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__NOTOC__
{{Irritable bowel syndrome}}
'''For patient information click [[{{PAGENAME}} (patient information)|here]]'''
'''For patient information click [[{{PAGENAME}} (patient information)|here]]'''
{{CMG}}; {{AE}} {{Cherry}}


{{CMG}}
{{SK}} Spastic colon, functional bowel disorder, IBS


{{Infobox_Disease |
== [[Irritable bowel syndrome overview|Overview]] ==
  Name          = Irritable bowel syndrome synonymous with GILL/HT/IB |
  Image          = |
  Caption        = |
  DiseasesDB    = 30638|
  ICD10          = {{ICD10|K|58||k|55}} |
  ICD9          = {{ICD9|564.1}} |
  ICDO          = |
  OMIM          = |
  MedlinePlus    = 000246|
  MeshID        = D043183 |
}}
{{Template:Irritable bowel syndrome}}
==Overview==
In [[gastroenterology]], '''irritable bowel syndrome''' ('''[[IBS]]''') or '''[[spastic colon]]''' is a [[functional bowel disorder]] characterized by [[abdominal pain]] and changes in [[bowel]] habits which are not associated with any abnormalities seen on routine clinical testing. It is fairly common and makes up 20–50% of visits to gastroenterologists. Lower [[Abdomen|abdominal]] pain, and bloating associated with alteration of bowel habits and abdominal discomfort relieved with defecation are the most frequent symptoms. The abdominal pain type is usually described in a patient as either [[diarrhea]]-predominant ('''IBS-D'''), [[constipation]]-predominant ('''IBS-C''') or IBS with alternating stool pattern ('''IBS-A'''). In some individuals, IBS may have an acute onset and develop after an [[infectious]] illness characterised by two or more of the following: [[fever]], [[vomiting]], [[Acute (medical)|acute]] [[diarrhea]], or positive stool culture. This post-infective syndrome has consequently been termed "post-infectious IBS" ('''IBS-PI''') and is acute onset Rome II criteria positive. This condition is more homogeneous, being mostly IBS-D and is drawing much clinical investigation.


[[Chronic functional abdominal pain]] (CFAP) is quite similar to, but less common than IBS. CFAP can be diagnosed if there is no change in bowel habits.
== [[Irritable bowel syndrome historical perspective|Historical Perspective]] ==


Because of the name, IBS can be confused with [[inflammatory bowel disease]] (IBD).
== [[Irritable bowel syndrome classification|Classification]] ==


==Symptoms==
== [[Irritable bowel syndrome pathophysiology|Pathophysiology]] ==
The symptoms of IBS are abdominal pain in association with frequent diarrhea, constipation, or a change in bowel habits.<ref name="SCHMULSON_1999">{{cite journal |author=Schmulson MW, Chang L |title=Diagnostic approach to the patient with irritable bowel syndrome |journal=Am. J. Med. |volume=107 |issue=5A |pages=20S-26S |year=1999 |pmid=10588169 |doi=}}</ref>


==Diagnosis==
== [[Irritable bowel syndrome causes|Causes]] ==
The underlying biochemical cause of IBS is not well established, so there is no specific laboratory test which can be performed to diagnose this condition.<ref name="YAWN_2001">{{cite journal |author=Yawn BP, Lydick E, Locke GR, Wollan PC, Bertram SL, Kurland MJ |title=Do published guidelines for evaluation of irritable bowel syndrome reflect practice? |journal=BMC gastroenterology |volume=1 |issue= |pages=11 |year=2001 |pmid=11701092 |doi=}}</ref>  Diagnosis of IBS involves excluding conditions which produce with IBS-like symptoms, and then following a procedure to categorize the patient's symptoms. 


Because there are many [[List of causes of diarrhea|causes of diarrhea]] and IBS-like symptoms, the [[American Gastroenterological Association]] has published a [[AGA Guidelines for IBS testing| set of guidelines]] for tests to be performed to diagnose other conditions which may have symptoms similar to IBS.  These include gastrointestinal infections, [[lactose intolerance]] and [[Coeliac disease]].  Research has suggested that these guidelines are not always followed.<ref name="YAWN_2001" />  Once other causes have been excluded, the diagnosis of IBS is performed using a diagnostic [[algorithm]].  Well-known [[algorithms]] include the [[Manning Criteria]], the [[Rome process|Rome I Criteria]], the [[Rome process|Rome II Process]], the Kruis Criteria, and studies have compared their reliability.<ref name="FASS_2001">{{cite journal |author=Fass R, Longstreth GF, Pimentel M, ''et al'' |title=Evidence- and consensus-based practice guidelines for the diagnosis of irritable bowel syndrome |journal=Arch. Intern. Med. |volume=161 |issue=17 |pages=2081-8 |year=2001 |pmid=11570936 |doi=}}</ref>  The more recent [[Rome process|Rome III Process]] was published in 2006. Physicians may choose to use one of these criteria, or may use other guidelines based on their own experience and the patient's history.  The [[algorithm]] may include additional tests to guard against mis-diagnosis of other diseases as IBS.  Such "red flag" symptoms may include weight loss, GI bleeding, anemia, or nocturnal symptoms.  However, researchers have noted that red flag conditions may not always contribute to accuracy in diagnosis &mdash; for instance, as many as 31% of IBS patients have blood in their stool.<ref name="FASS_2001" /> 
== [[Irritable bowel syndrome differential diagnosis|Differentiating Irritable Bowel Syndrome from other Diseases]] ==


The diagnostic [[algorithm]] identifies a name which can be applied to the patient's condition based on the combination of the patient's symptoms of [[diarrhea]], abdominal pain, and constipation.  For example, the statement "50% of returning travelers had developed functional [[diarrhea]] while 25% had developed IBS" would mean that half the travelers had [[diarrhea]] while a quarter had [[diarrhea]] with abdominal pain.  While some researchers believe this categorization system will help physicians understand IBS, others have questioned the value of the system and suggested that all IBS patients have the same underlying disease but with different symptoms.<ref name="TALLEY_2006">{{cite journal |author=Talley NJ |title=A unifying hypothesis for the functional gastrointestinal disorders: really multiple diseases or one irritable gut? |journal=Reviews in gastroenterological disorders |volume=6 |issue=2 |pages=72-8 |year=2006 |pmid=16699476 |doi=}}</ref>
== [[Irritable bowel syndrome epidemiology and demographics|Epidemiology and Demographics]] ==


===Misdiagnosis===
== [[Irritable bowel syndrome risk factors|Risk Factors]] ==
Published research has demonstrated that some poor patient outcomes are due to treatable causes of diarrhea being mis-diagnosed as IBS.  Common examples include [[infectious diseases]], [[celiac disease]],<ref>{{cite journal |author=Spiegel BM, DeRosa VP, Gralnek IM, Wang V, Dulai GS |title=Testing for celiac sprue in irritable bowel syndrome with predominant diarrhea: a cost-effectiveness analysis |journal=Gastroenterology |volume=126 |issue=7 |pages=1721-32 |year=2004 |pmid=15188167 |doi=}}</ref> parasites,<ref>{{cite journal |author=Stark D, van Hal S, Marriott D, Ellis J, Harkness J. |title=Irritable bowel syndrome: a review on the role of intestinal protozoa and the importance of their detection and diagnosis. |journal=Int J Parasitol. |volume= 31 |issue=1 |pages=11-20 |year=2007 |pmid=17070814 |doi=}}</ref> food allergies<ref>{{cite journal |author=Drisko ''et al'' |title=Treating Irritable Bowel Syndrome with a Food Elimination Diet Followed by Food Challenge and Probiotics |journal=Journal of the American College of Nutrition |volume=25 |issue=6 |pages=514-22 |year=2006 |pmid=17229899 |doi=}}</ref>
(though considered controversial),  and [[lactose intolerance]].<ref>{{cite journal |author=Vernia P, Ricciardi MR, Frandina C, Bilotta T, Frieri G |title=Lactose malabsorption and irritable bowel syndrome. Effect of a long-term lactose-free diet |journal=The Italian journal of gastroenterology |volume=27 |issue=3 |pages=117-21 |year=1995 |pmid=7548919 |doi=}}</ref>  See '''[[List of causes of diarrhea]]''' for other conditions which can cause diarrhea.


[[Coeliac disease]] in particular is often misdiagnosed as IBS: <blockquote>
== [[Irritable bowel syndrome screening|Screening]] ==
Recognizing celiac disease can be difficult because some of its symptoms are similar to those of other diseases. In fact, sometimes celiac disease is confused with irritable bowel syndrome, iron-deficiency anemia caused by menstrual blood loss, Crohn’s disease, diverticulitis, intestinal infections, and chronic fatigue syndrome. As a result, celiac disease is commonly underdiagnosed or misdiagnosed.<ref>http://digestive.niddk.nih.gov/ddiseases/pubs/celiac/ - The United States National Institutes of Health Celiac Disease Page</ref></blockquote>


==Medical conditions that accompany IBS==
== [[Irritable bowel syndrome natural history, complications and prognosis|Natural History, Complications and Prognosis]] ==
Researchers have identified several medical conditions, or [[comorbidities]], which appear with greater frequency in patients diagnosed with IBS. 


:'''Headache, [[Fibromyalgia]], and Depression''':  A study of 97,593 individuals with IBS identified comorbidities as headache, [[fibromyalgia]], and depression.<ref>{{cite journal |author=Cole JA, Rothman KJ, Cabral HJ, Zhang Y, Farraye FA |title=Migraine, [[fibromyalgia]], and depression among people with IBS:  a prevalence study |journal=BMC gastroenterology |volume=6 |issue= |pages=26 |year=2006 |pmid=17007634 |doi=10.1186/1471-230X-6-26}}</ref>  [[Fibromyalgia]] has also been identified in other studies as a comorbidity of IBS.<ref name="pmid16614951">{{cite journal |author=Kurland JE, Coyle WJ, Winkler A, Zable E |title=Prevalence of irritable bowel syndrome and depression in [[fibromyalgia]] |journal=Dig. Dis. Sci. |volume=51 |issue=3 |pages=454-60 |year=2006 |pmid=16614951 |doi=10.1007/s10620-006-3154-7}}</ref><ref name="pmid16042909">{{cite journal |author=Frissora CL, Koch KL |title=Symptom overlap and comorbidity of irritable bowel syndrome with other conditions |journal=Current gastroenterology reports |volume=7 |issue=4 |pages=264-71 |year=2005 |pmid=16042909 |doi=}}</ref>
== Diagnosis ==


:'''[[Inflammatory bowel disease]]''': Some researchers have suggested that IBS is a type of low-grade inflammatory bowel disease.<ref name="BERCIK_2005">{{cite journal |author=Bercik P, Verdu EF, Collins SM |title=Is irritable bowel syndrome a low-grade inflammatory bowel disease? |journal=Gastroenterol. Clin. North Am. |volume=34 |issue=2 |pages=235-45, vi-vii |year=2005 |pmid=15862932 |doi=10.1016/j.gtc.2005.02.007}}</ref> Researchers have suggested that IBS and IBD are interrelated diseases,<ref name="QUIGLEY_2005">{{cite journal |author=Quigley EM |title=Irritable bowel syndrome and inflammatory bowel disease: interrelated diseases? |journal=Chinese journal of digestive diseases |volume=6 |issue=3 |pages=122-32 |year=2005 |pmid=16045602 |doi=10.1111/j.1443-9573.2005.00202.x}}</ref> noting that patients with IBD experience IBS-like symptoms when their IBD is in remission.<ref name="SIMREN_2002">{{cite journal |author=Simrén M, Axelsson J, Gillberg R, Abrahamsson H, Svedlund J, Björnsson ES |title=Quality of life in inflammatory bowel disease in remission: the impact of IBS-like symptoms and associated psychological factors |journal=Am. J. Gastroenterol. |volume=97 |issue=2 |pages=389-96 |year=2002 |pmid=11866278 |doi=}}</ref><ref name="MINDERHOUD_2004">{{cite journal |author=Minderhoud IM, Oldenburg B, Wismeijer JA, van Berge Henegouwen GP, Smout AJ |title=IBS-like symptoms in patients with inflammatory bowel disease in remission; relationships with quality of life and coping behavior |journal=Dig. Dis. Sci. |volume=49 |issue=3 |pages=469-74 |year=2004 |pmid=15139501 |doi=}}</ref>  A 3-year study found that patients diagnosed with IBS were 16.3 times more likely to develop IBD during the study period.<ref name="GARCIA_2000">{{cite journal |author=García Rodríguez LA, Ruigómez A, Wallander MA, Johansson S, Olbe L |title=Detection of colorectal tumor and inflammatory bowel disease during follow-up of patients with initial diagnosis of irritable bowel syndrome |journal=Scand. J. Gastroenterol. |volume=35 |issue=3 |pages=306-11 |year=2000 |pmid=10766326 |doi=}}</ref>  Serum markers associated with inflammation have also been found in patients with IBS (see Causes).
[[Irritable bowel syndrome history and symptoms|History and Symptoms]] | [[Irritable bowel syndrome physical examination|Physical Examination]] | [[Irritable bowel syndrome laboratory findings|Laboratory Findings]] | [[Irritable bowel syndrome x ray|X Ray]] | [[Irritable bowel syndrome CT|CT]] | [[Irritable bowel syndrome MRI|MRI]] | [[Irritable bowel syndrome ultrasound|Ultrasound]] | [[Irritable bowel syndrome other imaging findings|Other Imaging Findings]] | [[Irritable bowel syndrome other diagnostic studies|Other Diagnostic Studies]]


:'''Abdominal surgery''': A 2005 study published in ''Digestive Disease Science'' reported that IBS patients are 87% more likely to undergo abdominal and pelvic surgery, and three times more likely to undergo gallbladder surgery.<ref name="pmid16416174">{{cite journal |author=Cole JA, Yeaw JM, Cutone JA, ''et al'' |title=The incidence of abdominal and pelvic surgery among patients with irritable bowel syndrome |journal=Dig. Dis. Sci. |volume=50 |issue=12 |pages=2268–75 |year=2005 |pmid=16416174 |doi=10.1007/s10620-005-3047-1}}</ref>  A study published in ''Gastroenterology'' came to similar conclusions, and also noted IBS patients were twice as likely to undergo hysterectomy.<ref name="pmid15188159">{{cite journal |author=Longstreth GF, Yao JF |title=Irritable bowel syndrome and surgery: a multivariable analysis |journal=Gastroenterology |volume=126 |issue=7 |pages=1665–73 |year=2004 |pmid=15188159 |doi=}}</ref>
== Treatment ==
[[Irritable bowel syndrome medical therapy|Medical Therapy]] | [[Irritable bowel syndrome monitoring|Monitoring]] | [[Irritable bowel syndrome surgery|Surgery]] | [[Irritable bowel syndrome primary prevention|Primary Prevention]] | [[Irritable bowel syndrome secondary prevention|Secondary Prevention]] | [[Irritable bowel syndrome cost-effectiveness of therapy|Cost-Effectiveness of Therapy]]


:'''[[Endometriosis]]''': One study has reported a statistically significant link between migraine headaches, IBS, and endometriosis.<ref name="pmid17635599">{{cite journal |author=Tietjen GE, Bushnell CD, Herial NA, Utley C, White L, Hafeez F |title=Endometriosis is associated with prevalence of comorbid conditions in migraine |journal=Headache |volume=47 |issue=7 |pages=1069-78 |year=2007 |pmid=17635599 |doi=10.1111/j.1526-4610.2007.00784.x}}</ref>
==Case Studies==
[[Irritable bowel syndrome case study one|Case #1]]


==Etiology==
==Related Chapters==
Initially, IBS was considered a psychosomatic illness and the involvement of biological and pathogenic factors was not verified until the 1990s, a process common in the [[history of emerging infectious diseases]].  The risk of developing IBS increases six-fold after acute gastrointestinal infection.  Post-infection, further risk factors are young age, prolonged fever, anxiety and depression.<ref>{{cite journal | author = Thabane M, Kottachchi DT, Marshall JK | title = The incidence and prognosis of post-infectious irritable bowel syndrome. | journal = Aliment Pharmacol Ther | volume = 26 | issue = 4 | pages = 535-44 | year = 2007 | pmid = 17661757}}</ref>
[[AGA Guidelines for IBS testing]]
 
{{WH}}
===Psychosomatic illness===
{{WS}}
One of the first references to the concept of an "Irritable Bowel" appeared in the Rocky Mountain Medical Journal in 1950.<ref name="BROWN_1950">{{cite journal |author=BROWN PW |title=The irritable bowel syndrome |journal=Rocky Mountain medical journal |volume=47 |issue=5 |pages=343-6 |year=1950 |pmid=1541
8074
|doi=}}</ref>  The term was used to categorize patients who developed symptoms of diarrhea, abdominal pain, constipation, but where no well-recognized infective cause could be found.  Early theories suggested that the Irritable Bowel was caused by a [[Somatoform disorder|somatic]], or mental disorder.  One paper from the 1980s investigated "learned illness behavior" in patients with IBS and [[peptic ulcers]].<ref name="WHITEHEAD_1982">{{cite journal |author=Whitehead WE, Winget C, Fedoravicius AS, Wooley S, Blackwell B |title=Learned illness behavior in patients with irritable bowel syndrome and peptic ulcer |journal=Dig. Dis. Sci. |volume=27 |issue=3 |pages=202-8 |year=1982 |pmid=7075418 |doi=}}</ref>  Another study suggested that both IBS and stomach ulcer patients would benefit from 15 months of [[psychotherapy]].<ref name="pmid3895386">{{cite journal |author=Svedlund J, Sjödin I |title=A psychosomatic approach to treatment in the irritable bowel syndrome and peptic ulcer disease with aspects of the design of clinical trials |journal=Scand. J. Gastroenterol. Suppl. |volume=109 |issue= |pages=147-51 |year=1985 |pmid=3895386 |doi=}}</ref>  Later, it would be found that most stomach ulcers were caused by a bacterial infection with ''[[Helicobacter pylori]].''<ref name="pmid9191460">{{cite journal |author=Damianos AJ, McGarrity TJ |title=Treatment strategies for Helicobacter pylori infection |journal=American family physician |volume=55 |issue=8 |pages=2765–74, 2784–6 |year=1997 |pmid=9191460 |doi=}}</ref>
 
Additional publications suggesting the role of brain-gut "axis" appeared in the 1990s, such as a study entitled ''Brain-gut response to stress and cholinergic stimulation in IBS'' published in the ''Journal of Clinical Gastrotnerology'' in 1993.<ref>{{cite journal |author=Fukudo S, Nomura T, Muranaka M, Taguchi F |title=Brain-gut response to stress and cholinergic stimulation in irritable bowel syndrome. A preliminary study |journal=J. Clin. Gastroenterol. |volume=17 |issue=2 |pages=133-41 |year=1993 |pmid=8031340 |doi=}}</ref>  A 1997 study published in ''Gut'' magazine suggested that IBS was associated with a "derailing of the brain-gut axis."<ref>{{cite journal |author=Orr WC, Crowell MD, Lin B, Harnish MJ, Chen JD |title=Sleep and gastric function in irritable bowel syndrome: derailing the brain-gut axis |journal=Gut |volume=41 |issue=3 |pages=390-3 |year=1997 |pmid=9378397 |doi=}}</ref>
 
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{{"
|There was a greater improvement in the psychotherapy groups for patients with IBS after three months and for both IBS and PUD (peptic ulcer disease) patients after 15 months. The difference had become more pronounced after 15 months, with the patients given psychotherapy showing further improvement, and the patients who had received medical treatment only showing some deterioration.
|by J Svedlund, ''A psychosomatic approach to treatment in the irritable bowel syndrome and peptic ulcer disease with aspects of the design of clinical trials'', 1985. 
}}
 
''Most peptic ulcers are now treated with 1-2 weeks of antibiotic therapy, since it has been discovered that they are caused by a combination of a genetic trait in the patient and infection with the bacteria [[H. Pylori]].''<ref name="EL-OMAR_2000"> {{cite journal |author=El-Omar EM, Carrington M, Chow WH, ''et al'' |title=Interleukin-1 polymorphisms associated with increased risk of gastric cancer |journal=Nature |volume=404 |issue=6776 |pages=398-402 |year=2000 |pmid=10746728 |doi=10.1038/35006081}} </ref>
 
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===Immune reaction===
 
From the late 1990s, research publications began identifying specific biochemical changes present in tissue biopsies and serum samples from IBS patients that suggested symptoms had an organic rather than [[psychosomatic]] cause.  These studies identified [[cytokine]]s and secretory products in tissues taken from IBS patients.  The cytokines identified in IBS patients produce [[inflammation]] and are associated with the body's [[Immunity (medical)|immune]] response.
 
* A study showed that intestinal [[biopsies]] from patients with constipation predominant IBS secreted higher levels of [[serotonin]] in-vitro.<ref>{{cite journal |author=Miwa J, Echizen H, Matsueda K, Umeda N |title=Patients with constipation-predominant irritable bowel syndrome (IBS) may have elevated serotonin concentrations in colonic mucosa as compared with diarrhea-predominant patients and subjects with normal bowel habits |journal=Digestion |volume=63 |issue=3 |pages=188-94 |year=2001 |pmid=11351146 |doi=}}</ref>  [[Serotonin]] plays a role in regulating gastrointestinal motility and water content, and can be altered by some diseases and infections.<ref name="MCGOWAN_1983"> {{cite journal |author=McGowan K, Kane A, Asarkof N, ''et al'' |title=Entamoeba histolytica causes intestinal secretion: role of serotonin |journal=Science |volume=221 |issue=4612 |pages=762-4 |year=1983 |pmid=6308760 |doi=}} </ref><ref name="MCGOWAN_1985"> {{cite journal |author=McGowan K, Guerina V, Wicks J, Donowitz M |title=Secretory hormones of Entamoeba histolytica |journal=Ciba Found. Symp. |volume=112 |issue= |pages=139-54 |year=1985 |pmid=2861068 |doi=}} </ref><ref>{{cite journal |author=Banu, Naheed, et al. |title=Neurohumoral alterations and their role in amoebiasis. |journal=Indian J. Clin Biochem |volume=20 |issue=2 |pages=142-5 |year=2005 |url=http://medind.nic.in/iaf/t05/i2/iaft05i2p142.pdf}}</ref>
 
* A study of rectal biopsy tissue from IBS patients showed increased levels of cellular structures involved in the production of the cytokine [[Interleukin 1]] Beta.<ref>{{cite journal |author=Gwee KA, Collins SM, Read NW, ''et al'' |title=Increased rectal mucosal expression of interleukin 1beta in recently acquired post-infectious irritable bowel syndrome |journal=Gut |volume=52 |issue=4 |pages=523-6 |year=2003 |pmid=12631663 |doi=}}</ref>
 
* A study of blood samples from IBS patients identified elevated levels of cytokines [[Tumor necrosis factor-alpha]], [[Interleukin 1]], and [[Interleukin 6]] in patients with IBS.<ref name="pmid17383420">{{cite journal |author=Liebregts T, Adam B, Bredack C, ''et al'' |title=Immune activation in patients with irritable bowel syndrome |journal=Gastroenterology |volume=132 |issue=3 |pages=913-20 |year=2007 |pmid=17383420 |doi=10.1053/j.gastro.2007.01.046}}</ref>
 
* A study of intestinal biopsies from IBS patients showed increased levels of [[protease]] enzymes used by the body to digest proteins, and by infectious agents to combat the host's [[immune system]].<ref>{{cite journal |author=Cenac N, Andrews CN, Holzhausen M, ''et al'' |title=Role for protease activity in visceral pain in irritable bowel syndrome |journal=J. Clin. Invest. |volume=117 |issue=3 |pages=636-47 |year=2007 |pmid=17304351 |doi=10.1172/JCI29255}}</ref>
 
* A study of blood samples from IBS patients found elevated levels of [[antibodies]] to the [[protozoan]] ''[[Blastocystis]]''.<ref name="HUSSAIN_1997">{{cite journal |author=Hussain R, Jaferi W, Zuberi S, ''et al'' |title=Significantly increased IgG2 subclass antibody levels to Blastocystis hominis in patients with irritable bowel syndrome |journal=Am. J. Trop. Med. Hyg. |volume=56 |issue=3 |pages=301-6 |year=1997 |pmid=9129532 |doi=}}</ref>
 
Specific forms of immune response that have been implicated in IBS symptoms include [[Coeliac disease]] and other [[Food allergy]] conditions.<ref name="Wangen_2006">Wangen, Dr. Stephen. ''The Irritable Bowel Syndrome Solution''. 2006. ISBN 0976853787. Excerpted with author's permission at [http://www.IBSTreatmentCenter.com/]</ref>  [[Coeliac disease]] (also spelled "celiac") is an immunoglobulin type A-(IgA) mediated allergic response to the [[Gliadin]] protein in gluten grains,which exhibits wide variety of symptoms and can present as IBS.  "Some patients with diarrhea-predominant irritable bowel syndrome (IBS-D) may have undiagnosed celiac sprue (CS). Because the symptoms of CS respond to a gluten-free diet, testing for CS in IBS may prevent years of morbidity and attendant expense."<ref>{{cite journal |author=Spiegel BM, ''et al'' |title=Testing for celiac sprue in irritable bowel syndrome with predominant diarrhea: a cost-effectiveness analysis. |journal=Gastroenterology |volume=126 |issue=7 |pages=1721-32 |year=2004 |pmid=15188167 |doi=}}</ref>  "Coeliac disease is a common finding among patients labelled as irritable bowel syndrome. In this sub-group, a gluten free diet may lead to a significant improvement in symptoms. Routine testing for coeliac disease may be indicated in all patients being evaluated for irritable bowel syndrome."<ref>{{cite journal |author=Shahbazkhani B, ''et al'' |title=Coeliac disease presenting with symptoms of irritable bowel syndrome. |journal=Aliment Pharmacol Therapy |volume=18 |issue=2 |pages=231-5 |year=2003 |pmid=12869084 |doi=}}</ref>  Food allergies, particularly those mediated by IgE and IgG-type antibodies have been implicated in IBS.<ref>{{cite journal |author=Li H, ''et al'' |title=Allergen-IgE complexes trigger CD23-dependent CCL20 release from human intestinal epithelial cells. |journal=Gastroenterology |volume=133 |issue=6 |pages=1905-15 |year=2007 |pmid=18054562 |doi=}}</ref><ref>{{cite journal |Yang CM, Li YQ |title=The therapeutic effects of eliminating allergic foods according to food-specific IgG antibodies in irritable bowel syndrome - Article in Chinese |journal=Zhonghua Nei Ke Za Zhi. |volume=46 |issue=8 |pages=641-3 |year=2007 |pmid=17967233 |doi=}}</ref><ref>{{cite journal |author=Drisko ''et al'' |title=Treating Irritable Bowel Syndrome with a Food Elimination Diet Followed by Food Challenge and Probiotics |journal=Journal of the American College of Nutrition |volume=25 |issue=6 |pages=514-22 |year=2006 |pmid=17229899 |doi=}}</ref>
 
===Active infections===
 
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{{"
|Clearly this study highlights a new concept in the potential pathogenesis of IBS.  An infectious cause may offer a tremendous opportunity to manage an otherwise frustrating disease -- both for patients and their treating physician.
|by Dr. David A. Johnson, President of the [[American College of Gastroenterology]] , commenting on results from study of Rifaximin in treatment of IBS<ref>{{cite journal |author=Johnson, David. |title=Viewpoints: Efficacy of Rifaximin vs Placebo in Reducing Symptoms in Adults With IBS. |journal=Medscape Gastroenterology |volume=8 |issue=2 |year=2006 |url=http://www.medscape.com/viewarticle/547055}}</ref>
}}
 
</div>
 
There is research to support IBS being caused by an as-yet undiscovered active infection.  Most recently, a study has found that the antibiotic [[Rifaximin]] provides sustained relief for IBS patients.<ref name="pmid17043337">{{cite journal |author=Pimentel M, Park S, Mirocha J, Kane SV, Kong Y |title=The effect of a nonabsorbed oral antibiotic (rifaximin) on the symptoms of the irritable bowel syndrome: a randomized trial |journal=Ann. Intern. Med. |volume=145 |issue=8 |pages=557-63 |year=2006 |pmid=17043337 |doi=}}</ref>  While some researchers see this as evidence that IBS is related to an undiscovered agent, others believe IBS patients suffer from overgrowth of [[Gut flora|intestinal flora]] and the antibiotics are effective in reducing the overgrowth (known as ''[[Small bowel bacterial overgrowth syndrome|small intestinal bacterial overgrowth]]'').<ref name="pmid17148502">{{cite journal |author=Posserud I, Stotzer PO, Björnsson ES, Abrahamsson H, Simrén M |title=Small intestinal bacterial overgrowth in patients with irritable bowel syndrome |journal=Gut |volume=56 |issue=6 |pages=802-8 |year=2007 |pmid=17148502 |doi=10.1136/gut.2006.108712}}</ref>  Other researchers have focused on an unrecognized [[protozoa]]l infection as a cause of IBS<ref name="STARK_2007">{{cite journal |author=Stark D, van Hal S, Marriott D, Ellis J, Harkness J |title=Irritable bowel syndrome: a review on the role of intestinal protozoa and the importance of their detection and diagnosis |journal=Int. J. Parasitol. |volume=37 |issue=1 |pages=11-20 |year=2007 |pmid=17070814 |doi=10.1016/j.ijpara.2006.09.009}}</ref> as certain protozoal infections occur more frequently in IBS patients.<ref name="YAKOOB_2004">{{cite journal |author=Yakoob J, Jafri W, Jafri N, ''et al'' |title=Irritable bowel syndrome: in search of an etiology: role of Blastocystis hominis |journal=Am. J. Trop. Med. Hyg. |volume=70 |issue=4 |pages=383-5 |year=2004 |pmid=15100450 |doi=}}</ref><ref name="GIACOM_1999">{{cite journal |author=Giacometti A, Cirioni O, Fiorentini A, Fortuna M, Scalise G |title=Irritable bowel syndrome in patients with Blastocystis hominis infection |journal=Eur. J. Clin. Microbiol. Infect. Dis. |volume=18 |issue=6 |pages=436-9 |year=1999 |pmid=10442423 |doi=}}</ref>  Two of the protozoa investigated have a high prevalence in industrialized countries and infect the bowel, but little is known about them as they are recently emerged pathogens.
 
''[[Blastocystis]]'' is a single-celled organism which has been reported to produce symptoms of abdominal pain, constipation and diarrhea in patients, along with headaches and depression,<ref name="QADRI_1989">{{cite journal |author=Qadri SM, al-Okaili GA, al-Dayel F |title=Clinical significance of Blastocystis hominis |journal=J. Clin. Microbiol. |volume=27 |issue=11 |pages=2407-9 |year=1989 |pmid=2808664 |doi=}}</ref> though these reports are contested by some physicians.<ref name="MARKELL_1986">{{cite journal |author=Markell EK, Udkow MP |title=Blastocystis hominis: pathogen or fellow traveler? |journal=Am. J. Trop. Med. Hyg. |volume=35 |issue=5 |pages=1023-6 |year=1986 |pmid=3766850 |doi=}}</ref>  Studies from research hospitals in various countries have identified high [[Blastocystis]] infection rates in IBS patients, with 38% being reported from [[London School of Hygiene & Tropical Medicine]],<ref name="WINDSOR_2007">{{cite journal |author=Windsor J |title=B. hominis and D. fragilis: Neglected human protozoa |journal=British Biomedical Scientist |pages=524-7 |year=2007 |pmid= |doi= |url=http://www.ibms.org/index.cfm?method=publications.biomedical_scientist&subpage=contents_2007_July}}</ref> 47% reported from the Department of Gastroenterology at [[Aga Khan University]] in Pakistan<ref name="YAKOOB_2004" /> and 18.1% reported from the Institute of Diseases and Public Health at [[University of Ancona]] in Italy.<ref name="GIACOM_1999" />  Reports from all three groups indicate a [[Blastocystis]] prevalence of approximately 7% in non-IBS patients.  Researchers have noted that clinical diagnostics fail to identify infection,<ref name="STENSVOLD_2006">{{cite journal |author=Stensvold R, Brillowska-Dabrowska A, Nielsen HV, Arendrup MC |title=Detection of Blastocystis hominis in unpreserved stool specimens by using polymerase chain reaction |journal=J. Parasitol. |volume=92 |issue=5 |pages=1081-7 |year=2006 |pmid=17152954 |doi=}}</ref> and ''Blastocystis'' may not respond to treatment with common antiprotozoals.<ref name="pmid15250669">{{cite journal |author=Yakoob J, Jafri W, Jafri N, Islam M, Asim Beg M |title=In vitro susceptibility of Blastocystis hominis isolated from patients with irritable bowel syndrome |journal=Br. J. Biomed. Sci. |volume=61 |issue=2 |pages=75-7 |year=2004 |pmid=15250669 |doi=}}</ref><ref name="pmid10357863">{{cite journal |author=Haresh K, Suresh K, Khairul Anus A, Saminathan S |title=Isolate resistance of Blastocystis hominis to metronidazole |journal=Trop. Med. Int. Health |volume=4 |issue=4 |pages=274-7 |year=1999 |pmid=10357863 |doi=}}</ref><ref name="pmid3766850">{{cite journal |author=Markell EK, Udkow MP |title=Blastocystis hominis: pathogen or fellow traveler? |journal=Am. J. Trop. Med. Hyg. |volume=35 |issue=5 |pages=1023-6 |year=1986 |pmid=3766850 |doi=}}</ref><ref name="pmid10566723">{{cite journal |author=Ok UZ, Girginkardeşler N, Balcioğlu C, Ertan P, Pirildar T, Kilimcioğlu AA |title=Effect of trimethoprim-sulfamethaxazole in Blastocystis hominis infection |journal=Am. J. Gastroenterol. |volume=94 |issue=11 |pages=3245-7 |year=1999 |pmid=10566723 |doi=}}</ref> 
 
{{Further|[[Blastocystosis]]}}
 
[[Image:Wiki ibs cause figures.jpg|thumb|200px|left|Prevalence of protozoal infections in industrialized countries (United States and Canada) in 21st century.<ref name="CMAJ_2006" /><ref name="pmid12224595">{{cite journal |author=Amin OM |title=Seasonal prevalence of intestinal parasites in the United States during 2000 |journal=Am. J. Trop. Med. Hyg. |volume=66 |issue=6 |pages=799-803 |year=2002 |pmid=12224595 |doi=}}</ref>]]
 
''[[Dientamoeba fragilis]]'' is a single-celled organism which produces abdominal pain and diarrhea.  Studies have reported a high incidence of infection in developed countries, and symptoms of patients resolve following antibiotic treatment.<ref name="CMAJ_2006">{{cite journal |author=Lagacé-Wiens PR, VanCaeseele PG, Koschik C |title=Dientamoeba fragilis: an emerging role in intestinal disease |journal=CMAJ : Canadian Medical Association journal &#61; journal de l'Association medicale canadienne |volume=175 |issue=5 |pages=468-9 |year=2006 |pmid=16940260 |doi=10.1503/cmaj.060265}}</ref><ref name="STENSVOLD_2007f">{{cite journal |author=Stensvold CR, Arendrup MC, Mølbak K, Nielsen HV |title=The prevalence of Dientamoeba fragilis in patients with suspected enteroparasitic disease in a metropolitan area in Denmark |journal=Clin. Microbiol. Infect. |volume=13 |issue=8 |pages=839-42 |year=2007 |pmid=17610603 |doi=10.1111/j.1469-0691.2007.01760.x}}</ref>  One study reported on a large group of patients with IBS-like symptoms who were found to be infected with ''Dientamoeba fragilis'', and experienced resolution of symptoms following treatment.<ref name="BORODY_2002">{{cite journal |author=Borody T, Warren E, Wettstein A, et al. | title = Eradication of Dientamoeba fragilis can resolve IBS-like symptoms.  | journal=J Gastroenterol Hepatol | year= 2002 | volume=17 | issue=Suppl; pages=A103}}</ref>  Researchers have noted that methods used clinically may fail to detect some ''[[Dientamoeba fragilis]]'' infections.<ref name="STENSVOLD_2007f" />
 
{{Further|[[Dientamoeba fragilis]]}}
 
 
 
 
 
 
 
 
==Treatment==
 
Treatment for IBS, as for any physiological condition, works best when it successfully addresses the cause of the condition.  The various conditions that can cause IBS, outlined in the [[#Diagnosis| Diagnosis]] and [[#Etiology| Etiology]] sections above, require specific treatments.  High rates of success in resolving IBS symptoms have been reported when treatment is specifically tailored to the underlying causes revealed through proper testing for the range of known causes of IBS symptoms.<ref name="Wangen_2006">Wangen, Dr. Stephen. ''The Irritable Bowel Syndrome Solution''. 2006. ISBN 0976853787. Excerpted with author's permission at [http://www.IBSTreatmentCenter.com/]</ref>
 
A questionnaire in 2006 designed to identify patients’ perceptions about IBS, their preferences on the type of information they need, as well as educational media and expectations from health care providers, revealed misperceptions about IBS developing into other conditions, including [[colitis]], [[malnutrition]], and [[cancer]].<ref name="JClinGastro2006-Halpert">{{cite journal | author=Halpert AD, Thomas AC, Hu Y, Morris CB, Bangdiwala SI, Drossman DA | title=A survey on patient educational needs in irritable bowel syndrome and attitudes toward participation in clinical research | journal=J Clin Gastroenterol | year=2006 | pages=37–43 | volume=40 | issue=1 | id=PMID 16340632}}</ref>
 
The survey found IBS patients were most interested in learning about foods to avoid (60%), causes of IBS (55%), medications (58%), coping strategies (56%), and psychological factors related to IBS (55%). The respondents indicated that they wanted their physician to be available via phone or e-mail following a visit (80%), have the ability to listen (80%), and provide hope (73%) and support (63%).
 
===Diet===
There are a number of dietary changes a person with IBS can make to prevent the overreaction of the gastrocolic reflex and lessen pain, discomfort, and bowel dysfunction. Having [[dietary fiber|soluble fiber]] foods and supplements, substituting milk products with soy or rice products, being careful with fresh fruits and vegetables that are high in [[dietary fiber|insoluble fiber]], and eating frequent meals of small amounts of food, can all help to lessen the symptoms of IBS. Foods and beverages to be avoided or minimized include red meat, oily or fatty and fried products, [[milk]] products (even when there is no [[lactose intolerance]]), solid [[chocolate]], [[coffee]] (regular and decaffeinated), [[alcoholic beverage|alcohol]], carbonated beverages, especially those containing [[sorbitol]] or other artificial sweeteners. Care, however, should be taken to avoid adding foods to the diet to which the patient is allergic or intolerant.<ref name="EatingForIBS2000-VanVorous">Van Vorous, Heather. ''Eating for IBS''. 2000. ISBN 1-56924-600-9. Excerpted with author's permission at [http://www.HelpForIBS.com/ Help for Irritable Bowel Syndrome] (see IBS Diet Section)</ref>
 
Definitive determination of dietary issues can be accomplished by testing for the physiological effects of specific foods. The [[ELISA]] food allergy panel can identify specific foods to which a patient has a reaction. Other testing can determine if there are nutritional deficiencies secondary to diet that may also play a role. Removal of foods causing IgG immune response as measured using the ELISA food panel has been shown to substantially decrease symptoms of IBS in several studies.<ref name="Gut2004-Atkinson">{{cite journal | author=Atkinson W, Sheldon TA, Shaath N, Whorwell PJ | title=Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial | journal=Gut | year=2004 | pages=1459–64 | volume=53 | issue=10 | id=PMID 15361495 [http://gut.bmjjournals.com/cgi/content/full/53/10/1459 Full text]}}</ref>
 
There is no evidence that digestion of food or absorption of nutrients is problematic for those with IBS at rates different from those without IBS. However, the very act of eating or drinking can provoke an overreaction of the [[gastrocolic response]] in some patients with IBS due to their heightened visceral sensitivity, and this can lead to abdominal pain, diarrhea, and/or constipation.<ref>{{cite journal | author = Sjölund K, Ekman R, Lindgren S, Rehfeld J | title = Disturbed motilin and cholecystokinin release in the irritable bowel syndrome. | journal = Scand J Gastroenterol | volume = 31 | issue = 11 | pages = 1110-4 | year = 1996 | id = PMID 8938905}}</ref>
 
Several of the most common dietary triggers are well-established by clinical studies at this point; research has shown that IBS patients are hypersensitive to fats and fructose.<ref name="AMJGastro2005-Caldarella">{{cite journal | author=Caldarella MP, Milano A, Laterza F, Sacco F, Balatsinou C, Lapenna D, Pierdomenico SD, Cuccurullo F, Neri M | title=Visceral sensitivity and symptoms in patients with constipation- or diarrhea-predominant irritable bowel syndrome (IBS): effect of a low-fat intraduodenal infusion | journal=Am J Gastroenterol | year=2005 | pages=383–9 | volume=100 | issue=2 | id=PMID 15667496}}</ref><ref name="ACG2003-Choi">Choi, Y. ''Fats, Fructose May Contribute to IBS Symptoms.'' ACG 68th Annual Scientific Meeting: Abstract 21, presented [[October 13]], [[2003]]; Abstract 547, presented [[October 14]], 2003.</ref>
 
It also appears that some foods are more difficult for the gut as evidenced by elevated food-specific IgG4 antibodies being present,<ref name="AmJGastro2005-Zar">{{cite journal | author=Zar S, Benson MJ, Kumar D | title=Food-specific serum IgG4 and IgE titers to common food antigens in irritable bowel syndrome | journal=Am J Gastroenterol | year=2005 | pages=1550–7 | volume=100 | issue=7 | id=PMID 15984980}}</ref><!-- original Harvard reference was for (Kumar, 2005) --><ref name="ScandJGastro2005-Zar">{{cite journal | author=Zar S, Mincher L, Benson MJ, Kumar D | title=Food-specific IgG4 antibody-guided exclusion diet improves symptoms and rectal compliance in irritable bowel syndrome | journal=Scand J Gastroenterol | year=2005 | pages=800–7 | volume=40 | issue=7 | id=PMID 16109655}}</ref><!-- other paper published by same group in same year --> while others increase colonic contractions, which may be painful, due to increased visceral sensitivity in IBS sufferers.<ref name="Pain2005-Mayer">{{cite journal | author=Mayer EA, Berman S, Suyenobu B, Labus J, Mandelkern MA, Naliboff BD, Chang L | title=Differences in brain responses to visceral pain between patients with irritable bowel syndrome and ulcerative colitis | journal=Pain | year=2005 | pages=398–409 | volume=115 | issue=3 | id=PMID 15911167}}</ref><!-- orig Harvard ref was for 2004, but only Pubmed from same group in 2004 seems to be "The Visceral Sensitivity Index" with Labus as lead-author PubMed 15225175-->
 
;Fiber:
In patients who do ''not'' have diarrhea predominant irritable bowel, soluble fiber at doses of 20 grams per day can reduce overall symptoms but will not reduce pain. The research supporting [[dietary fiber]] contains conflicting, small studies that are complicated by the heterogeneity of types of fiber and doses used.<ref name=pmid14984370>{{cite journal | author = Bijkerk C, Muris J, Knottnerus J, Hoes A, de Wit N | title = Systematic review: the role of different types of fibre in the treatment of irritable bowel syndrome. | journal = Aliment Pharmacol Ther | volume = 19 | issue = 3 | pages = 245-51 | year = 2004 | id = PMID 14984370}}</ref> The one [[meta-analysis]] that controlled for solubility found that only soluble fiber improved global symptoms of irritable bowel and neither type of fiber reduced pain<ref name=pmid14984370>.</ref> Positive studies have used 20-30 grams per day of [[psyllium]] seed.<ref name=pmid3322956>{{cite journal | author = Prior A, Whorwell P | title = Double blind study of ispaghula in irritable bowel syndrome. | journal = Gut | volume = 28 | issue = 11 | pages = 1510-3 | year = 1987 | id = PMID 3322956}}</ref><ref name=pmid2129822>{{cite journal | author = Jalihal A, Kurian G | title = Ispaghula therapy in irritable bowel syndrome: improvement in overall well-being is related to reduction in bowel dissatisfaction. | journal = J Gastroenterol Hepatol | volume = 5 | issue = 5 | pages = 507-13 | year = | id = PMID 2129822}}</ref>  One study specifically examined the effect of dose and found that 20 grams of ispaghula husk was better than 10 grams and equivalent to 30 grams per day<ref name=pmid3030900>{{cite journal | author = Kumar A, Kumar N, Vij J, Sarin S, Anand B | title = Optimum dosage of ispaghula husk in patients with irritable bowel syndrome: correlation of symptom relief with whole gut transit time and stool weight. | journal = Gut | volume = 28 | issue = 2 | pages = 150-5 | year = 1987 | id = PMID 3030900}}</ref>An uncontrolled study noted increased symptoms with insoluble fibers.<ref name="BranIBS1994-Francis">{{cite journal | author=Francis CY, Whorwell PJ | title=Bran and irritable bowel syndrome: time for reappraisal | journal=Lancet | year=1994 | pages=39–40 | volume=344 | issue=8914 | id=PMID 7912305}}</ref><!-- originally listed as of Worrwell 1994, but see entry as per PubMed --> It is unclear if these symptoms are truly increased compared to a control group. If the symptoms are increased, it is unclear if these patients were diarrhea predominant (which can be exacerbated by insoluble fiber<ref name=pmid6365490>{{cite journal | author = Cann P, Read N, Holdsworth C, Barends D | title = Role of loperamide and placebo in management of irritable bowel syndrome (IBS). | journal = Dig Dis Sci | volume = 29 | issue = 3 | pages = 239-47 | year = 1984 | id = PMID 6365490}}</ref><ref name=pmid6319244>{{cite journal | author = Cann P, Read N, Holdsworth C | title = What is the benefit of coarse wheat bran in patients with irritable bowel syndrome? | journal = Gut | volume = 25 | issue = 2 | pages = 168-73 | year = 1984 | id = PMID 6319244}}</ref>), or if the increase is temporary before benefit occurs. There is a mistaken presumption that fiber therapy only works for those with constipation. In actuality soluble fiber can act as a counterbalance to both constipation, by retaining water in the bowel, and for diarrhea, by absorbing excess water.
 
===Medication===
====Initial treatments====
Medications may consist of stool softeners and [[laxative]]s in constipation-predominant IBS, and antidiarrheals (e.g., [[opioid]] or opioid [[analog (chemistry)|analog]]s such as [[loperamide]], [[diphenoxylate]] or [[codeine]] in diarrhea-predominant IBS for mild symptoms.<ref name=pmid15846668>{{cite journal | author = Quartero A, Meineche-Schmidt V, Muris J, Rubin G, de Wit N | title = Bulking agents, antispasmodic and antidepressant medication for the treatment of irritable bowel syndrome. | journal = Cochrane Database Syst Rev | volume = | issue = | pages = CD003460 | year = | id = PMID 15846668}}</ref><ref name=pmid15606387>{{cite journal | author = Lesbros-Pantoflickova D, Michetti P, Fried M, Beglinger C, Blum A | title = Meta-analysis: The treatment of irritable bowel syndrome. | journal = Aliment Pharmacol Ther | volume = 20 | issue = 11-12 | pages = 1253-69 | year = 2004 | id = PMID 15606387}}</ref><ref name=pmid10896640>{{cite journal | author = Jailwala J, Imperiale T, Kroenke K | title = Pharmacologic treatment of the irritable bowel syndrome: a systematic review of randomized, controlled trials. | journal = Ann Intern Med | volume = 133 | issue = 2 | pages = 136-47 | year = 2000 | id = PMID 10896640}}</ref>
 
=====Laxatives=====
{{main|laxative}}
For patients who do not adequately respond to [[dietary fiber]], osmotic agents such as [[polyethylene glycol]], [[sorbitol]], and [[lactulose]] can help avoid 'cathartic colon' which has been associated with stimulant laxatives.<ref name=pmid9649012>{{cite journal | author = Joo J, Ehrenpreis E, Gonzalez L, Kaye M, Breno S, Wexner S, Zaitman D, Secrest K | title = Alterations in colonic anatomy induced by chronic stimulant laxatives: the cathartic colon revisited. | journal = J Clin Gastroenterol | volume = 26 | issue = 4 | pages = 283-6 | year = 1998 | id = PMID 9649012}}</ref>  Among the osmotic laxatives, 17 to 26 grams/day of [[polyethylene glycol]] (PEG) has been well studied.
 
=====Antispasmodics=====
{{main|antispasmodic}}
The use of antispasmodic drugs (e.g. [[anticholinergic]]s such as [[hyoscyamine]] or [[dicyclomine]]) may help patients, especially those with cramps or diarrhea. A [[meta-analysis]] by the [[Cochrane Collaboration]] concludes that if 6 patients are treated with antispasmodics, 1 patient will benefit ([[number needed to treat]] = 6).<ref name=pmid15846668/> Antispasmodics can be divided in two groups: neurotropics and musculotropics. Neurotropics, such as [[atropine]], act at the nerve fibre of the parasympathicus but also affect other nerves and have side effects. Musculotropics such as [[mebeverine]] act directly at the smooth muscle of the gastrointestinal tract, relieving spasm without affecting normal gut motility. Since this action is not mediated by the autonomic nervous system, the usual anticholinergic side effects are absent. Antispasmodic drugs are also available in combination with [[tranquilizers]] or [[barbiturates]], such as [[chlordiazepoxide]] and [[Donnatal]].  The value of the combination therapies has not been established.
 
====Drugs affecting serotonin (5-HT)====
Drugs affecting [[serotonin]] (5-HT) in the intestines can help reduce symptoms.<ref name=pmid11755632>{{cite journal | author = Talley N | title = Serotoninergic neuroenteric modulators. | journal = Lancet | volume = 358 | issue = 9298 | pages = 2061-8 | year = 2001 | id = PMID 11755632}}</ref> Serotonin stimulates the gut motility and so agonists can help constipation predominate irritable bowel while antagonists can help diarrhea predominant irritable bowel:
 
=====Agonists=====
*[[Tegaserod]], a selective 5-HT4 agonist for IBS-C, is available for relieving IBS constipation in women and chronic idiopathic constipation in men and women. On March 30, 2007, the Food and Drug Administration (FDA) requested that Novartis Pharmaceuticals voluntarily discontinue marketing of Zelnorm (tegaserod) based on the recently identified finding of an increased risk of serious cardiovascular adverse events (heart problems) associated with use of the drug. Novartis agreed to voluntarily suspend marketing of the drug in the United States and in many other countries. On July 27, 2007 the Food and Drug Administration (FDA) approved a limited treatment IND program for Zelnorm in the USA to allow restricted access to the medication for patients in need if no comparable alternative drug or therapy is available to treat the disease.  The USA FDA had issued two previous warnings about the serious consequences of Tegaserod. In 2005, Tegaserod was rejected as an IBS medication by the European Union. Tegaserod, marketed as Zelnorm in the United States, was the only agent approved to treat the multiple symptoms of IBS (in women only), including constipation, abdominal pain and bloating. A [[meta-analysis]] by the [[Cochrane Collaboration]] concludes that if 17 patients are treated with typical doses of [[tegaserod]], 1 patient will benefit ([[number needed to treat]] = 17).<ref name=pmid14974049>{{cite journal | author = Evans B, Clark W, Moore D, Whorwell P | title = Tegaserod for the treatment of irritable bowel syndrome. | journal = Cochrane Database Syst Rev | volume = | issue = | pages = CD003960 | year = | id = PMID 14974049}}</ref>
*[[Selective serotonin reuptake inhibitor]] [[anti-depressants]] (SSRIs), because of their serotonergic effect, would seem to help IBS, especially patients who are constipation predominant. Initial [[crossover studies]]<ref name=pmid16401691>{{cite journal | author = Tack J, Broekaert D, Fischler B, Oudenhove L, Gevers A, Janssens J | title = A controlled crossover study of the selective serotonin reuptake inhibitor citalopram in irritable bowel syndrome. | journal = Gut | volume = 55 | issue = 8 | pages = 1095-103 | year = 2006 | id = PMID 16401691}}</ref> and [[randomized controlled trials]]<ref name=pmid16128675>{{cite journal | author = Vahedi H, Merat S, Rashidioon A, Ghoddoosi A, Malekzadeh R | title = The effect of fluoxetine in patients with pain and constipation-predominant irritable bowel syndrome: a double-blind randomized-controlled study. | journal = Aliment Pharmacol Ther | volume = 22 | issue = 5 | pages = 381-5 | year = 2005 | id = PMID 16128675}}</ref><ref name=pmid12557136>{{cite journal | author = Creed F, Fernandes L, Guthrie E, Palmer S, Ratcliffe J, Read N, Rigby C, Thompson D, Tomenson B | title = The cost-effectiveness of psychotherapy and paroxetine for severe irritable bowel syndrome. | journal = Gastroenterology | volume = 124 | issue = 2 | pages = 303-17 | year = 2003 | id = PMID 12557136}}</ref><ref name=>{{cite journal | author = Tabas G, Beaves M, Wang J, Friday P, Mardini H, Arnold G | title = Paroxetine to treat irritable bowel syndrome not responding to high-fiber diet: a double-blind, placebo-controlled trial. | journal = Am J Gastroenterol | volume = 99 | issue = 5 | pages = 914-20 | year = 2004 | id = PMID 15128360}}</ref> support this role.
 
=====Antagonists=====
* [[Alosetron]], a selective 5-HT3 antagonist for IBS-D, which is only available for women in the United States under a restricted access program, due to severe risks of [[adverse drug reaction|side-effect]]s if taken mistakenly by IBS-A or IBS-C sufferers.
* [[Cilansetron]], also a selective 5-HT3 antagonist, is undergoing further clinical studies in Europe for IBS-D sufferers. In 2005, Solvay Pharmaceuticals withdrew Cilansetron from the United States regulatory approval process after receiving a "not approvable" action letter from the FDA requesting additional clinical trials.
 
====Other agents====
Anti-depressants include both [[tricyclic antidepressants]] (TCAs) and the newer [[selective serotonin reuptake inhibitors]] (SSRIs). In addition to improving symptoms via treating any co-existing depression, TCAs have anti-cholinergic actions while SSRIs are serotonergic. Thus in theory, TCAs would best treat diarrhea-predominant IBS while SSRIs would best treat constipation-predominant IBS. A [[meta-analysis]] of [[randomized controlled trials]] of mainly TCAs found 3 patients have to be treated with TCAs for one patient to improve ([[number needed to treat]] = 3).<ref name=pmid11059442>{{cite journal | author = Jackson J, O'Malley P, Tomkins G, Balden E, Santoro J, Kroenke K | title = Treatment of functional gastrointestinal disorders with antidepressant medications: a meta-analysis. | journal = Am J Med | volume = 108 | issue = 1 | pages = 65-72 | year = 2000 | id = PMID}}</ref> A separate [[randomized controlled trial]] found that TCAs are best for patients with diarrhea-predominant IBS.<ref name=pmid12851867>{{cite journal | author = Drossman D, Toner B, Whitehead W, Diamant N, Dalton C, Duncan S, Emmott S, Proffitt V, Akman D, Frusciante K, Le T, Meyer K, Bradshaw B, Mikula K, Morris C, Blackman C, Hu Y, Jia H, Li J, Koch G, Bangdiwala S | title = Cognitive-behavioral therapy versus education and desipramine versus placebo for moderate to severe functional bowel disorders. | journal = Gastroenterology | volume = 125 | issue = 1 | pages = 19-31 | year = 2003 | id = PMID}}</ref>
 
Recent studies have suggested that [[rifaximin]] can be used as an effective treatment for abdominal bloating and [[flatulence]],<ref name="AmJGastro2006-Sharara"> {{cite journal | author=Sharara AI, Aoun E, Abdul-Baki H, Mounzer R, Sidani S, Elhajj I | title=A randomized double-blind placebo-controlled trial of rifaximin in patients with abdominal bloating and flatulence | journal=Am J Gastroenterol | year=2006 | pages=326–33 | volume=101 | issue=2 | id=PMID}}</ref><ref name=pmid17043337>{{cite journal | author = Pimentel M, Park S, Mirocha J, Kane S, Kong Y | title = The effect of a nonabsorbed oral antibiotic (rifaximin) on the symptoms of the irritable bowel syndrome: a randomized trial. | journal = Ann Intern Med | volume = 145 | issue = 8 | pages = 557-63 | year = 2006 | id = PMID}}</ref> giving more credibility to the potential role of bacterial overgrowth in some patients with IBS.<ref name="AmJGastro2006-Quigley"> {{cite journal | author=Quigley EM | title=Germs, gas and the gut; the evolving role of the enteric flora in IBS | journal=Am J Gastroenterol | year=2006 | pages=334–5 | volume=101 | issue=2 | id=PMID}}</ref>
 
The multi-herbal extract [[Iberogast]] was found to be significantly superior to placebo via both an abdominal pain scale and an IBS symptom score after four weeks of treatment.<ref name="Madisch2004">{{cite journal|journal=Aliment Pharmacol Ther|title=Treatment of irritable bowel syndrome with herbal preparations: results of a double-blind, randomized, placebo-controlled, multi-centre trial|author=Madisch A, Holtmann G, Plein K, Holz J|year=2004|volume=19|pages=271&ndash;9}}</ref>
 
Enteric coated [[peppermint]] oil capsules has been advocated for IBS symptoms in adults and children;<ref name="AmFamPhysician2005-Hadley">{{cite journal | author=Hadley SK, Gaarder SM | title=Treatment of irritable bowel syndrome | journal=Am Fam Physician | year=2005 | pages=2501–6 | volume=72 | issue=12 | id=PMID}}</ref> however, results from trials have been inconsistent.<ref name=pmid3527248>{{cite journal | author = Nash P, Gould S, Bernardo D | title = Peppermint oil does not relieve the pain of irritable bowel syndrome. | journal = Br J Clin Pract | volume = 40 | issue = 7 | pages = 292-3 | year = 1986 | id = PMID}}</ref><ref name=pmid9430014>{{cite journal | author = Liu J, Chen G, Yeh H, Huang C, Poon S | title = Enteric-coated peppermint-oil capsules in the treatment of irritable bowel syndrome: a prospective, randomized trial. | journal = J Gastroenterol | volume = 32 | issue = 6 | pages = 765-8 | year = 1997 | id = PMID}}</ref>
 
For severe diarrhea-predominant IBS, more potent [[opioids]] may be used, such as [[codeine]] or [[propoxyphene]]; refractory cases may even be treated with [[paregoric]], or, more rarely, [[laudanum|deodorized tincture of opium]] or [[morphine sulfate]]. The use of opioids remains controversial due to the lack of evidence supporting their benefit and the potential risk of [[tolerance]], [[physical dependence]] and [[addiction]].<ref>{{cite book |title=Principles and Practice of Pain Medicine |last=Warfield |first=Carol A. |coauthors=Zahid H. Bajwa |year=2003 |publisher=McGraw-Hill Professional |isbn=0071443495 }}</ref>
 
[[Cannabis]] has theoretical support for its role,<ref name=pmid16133420>{{cite journal | author = Massa F, Storr M, Lutz B | title = The endocannabinoid system in the physiology and pathophysiology of the gastrointestinal tract. | journal = J Mol Med | volume = 83 | issue = 12 | pages = 944-54 | year = 2005 | id = PMID}}</ref><ref name=pmid15159679>{{cite journal | author = Russo E | title = Clinical endocannabinoid deficiency (CECD): can this concept explain therapeutic benefits of cannabis in migraine, fibromyalgia, irritable bowel syndrome and other treatment-resistant conditions? | journal = Neuro Endocrinol Lett | volume = 25 | issue = 1-2 | pages = 31-9 | year = | id = PMID}}</ref> but has not been subject of clinical studies. Although illegal in many counties, it has been prescribed to patients in nations such as [[Canada]]. Some of the argued benefits of cannabis are the reduction of pain and nausea, appetite stimulation, and assisting in falling asleep.
 
===Psychotherapy and hypnotherapy===
There is a strong brain-gut component to IBS, and [[cognitive therapy]] may improve symptoms in a portion of patients in conjunction with [[antidepressant]]s.<ref name="BMJ2005-Kennedy">{{cite journal | author=Kennedy T, Jones R, Darnley S, Seed P, Wessely S, Chalder T | title=Cognitive behaviour therapy in addition to antispasmodic treatment for irritable bowel syndrome in primary care: randomised controlled trial | journal=BMJ | year=2005 | pages=435 | volume=331 | issue=7514 | id=PMID 16093252 [http://bmj.bmjjournals.com/cgi/content/full/331/7514/435 Full text]}}</ref> In a [[randomized controlled trial]] of referred patients, [[cognitive behavioral therapy]] helped even though patients in this study ''did not'' have any psychiatric diagnoses.<ref name=pmid10763948>{{cite journal | author = Heymann-Mönnikes I, Arnold R, Florin I, Herda C, Melfsen S, Mönnikes H | title = The combination of medical treatment plus multicomponent behavioral therapy is superior to medical treatment alone in the therapy of irritable bowel syndrome. | journal = Am J Gastroenterol | volume = 95 | issue = 4 | pages = 981-94 | year = 2000 | id = PMID 10763948}}</ref>
 
Gut-directed or gut-specific [[hypnotherapy]] or self-hypnosis is one of the most promising areas of IBS treatment. An uncontrolled study shows that symptom reduction/elimination from IBS hypnotherapy can last at least five years.<ref name="Gut2003-Gonsalkorale"> {{cite journal | author=Gonsalkorale WM, Miller V, Afzal A, Whorwell PJ | title=Long term benefits of hypnotherapy for irritable bowel syndrome | journal=Gut | year=2003 | pages=1623–9 | volume=52 | issue=11 | id=PMID 14570733}}</ref>
 
Relaxation therapy in four 90-minute group sessions was found to help in a [[randomized controlled trial]].<ref name="pmid17767479">VAN DER Veek PP, VAN Rood YR, Masclee AA. Clinical trial: short- and long-term benefit of relaxation training for irritable bowel syndrome.Aliment Pharmacol Ther. 2007 Sep 15;26(6):943-52. PMID 17767479</ref>
 
===Alternative treatments===
;Probiotics:
[[Probiotics]] are generally accepted to be potentially beneficial strains of [[bacteria]] and [[yeast]], often found in the human gut. One research study has shown a clear link between the ingestion of [[Lactobacillus plantarum]] LP299V and sufferers of IBS who reported resolution of their abdominal pain.<ref name="EurJGastroHepatol2001-Niedzielin"> {{cite journal | author=Niedzielin K, Kordecki H, Birkenfeld B | title=A controlled, double-blind, randomized study on the efficacy of [[Lactobacillus]] plantarum 299V in patients with irritable bowel syndrome | journal=Eur J Gastroenterol Hepatol | year=2001 | pages=1143–7 | volume=13 | issue=10 | id=PMID 11711768}}</ref> Another study showed the utility of B. infantis 35625, a strain of [[Bifidobacteria]], in normalizing bowel movement frequency in sufferers of IBS.<ref name="AmColGastro2005-StudiesProbiotics">[http://www.acg.gi.org/media/releases/ACG05Release_ProbioticsinIBS.pdf New Studies Examine the Evidence of Probiotics on IBS] (Oct 2005). American College of Gastrointerologists. Retrieved on March 2, 2006</ref> Some practitioners of [[Integrative Medicine]] now recommend a strain of [[Lactobacillus]] known commonly as "LGG" after its discoverers Gorbach and Goldin. This strain in particular has shown an ability to endure the acidic environment of the stomach and survive until presentation to the intestinal tract
 
A prospective placebo-controlled study found patients with diarrhea predominant IBS taking ''[[Saccharomyces boulardii]]'', a probiotic [[yeast]], had a significant reduction on the number and improvement in consistency of bowel movements.<ref>{{ cite journal | title=Treatment of irritable bowel syndrome with ''Saccharomyces boulardii'': a double blind, placebo controlled study | year=1983 | journal=Medicine Chirurgie Digestives | author=Maupas J, Champemont P, Delforge M | volume=12(1) | pages=77&ndash;9}}</ref>
 
;Acupuncture:
Many sufferers of IBS seek relief using [[Acupuncture]], a component of [[Traditional Chinese Medicine]]. The [[meta-analysis]] by the [[Cochrane Collaboration]] concluded 'Most of the trials included in this review were of poor quality and were heterogeneous in terms of interventions, controls, and outcomes measured. With the exception of one outcome in common between two trials, data were not combined. Therefore, it is still inconclusive whether acupuncture is more effective than sham acupuncture or other interventions for treating IBS'.<ref name=pmid17054239>{{cite journal | author = Lim B, Manheimer E, Lao L, Ziea E, Wisniewski J, Liu J, Berman B | title = Acupuncture for treatment of irritable bowel syndrome. | journal = Cochrane Database Syst Rev | volume = | issue = | pages = CD005111 | year = | id = PMID 17054239}}</ref> One practitioner of Traditional Chinese Medicine asserts that IBS has become a bit of a "garbage diagnosis" for some medical practitioners. Traditional Chinese Medicine does not recognize the Western diagnosis of IBS per se, as the named condition has no definitive single test for diagnosis, clear cause, or cure. Traditional Chinese Medicine approaches IBS on an individual symptom-by-symptom basis, rather than recognizing a standard "IBS" diagnosis, which then warrants a blanket "IBS" treatment.<ref name="IBSTCM2006-Stone"> [http://beyondwellbeing.com/ibs/ Irritable Bowel Syndrome - A Traditional Chinese Medicine Perspective], (2006). Al Stone L.Ac. Retrieved on February 14, 2006.</ref> According to the National Institutes of Health, "Preclinical studies have documented acupuncture's effects, but they have not been able to fully explain how acupuncture works within the framework of the Western system of medicine that is commonly practiced in the United States."<ref name="NCCAM2006-Acupuncture">[http://nccam.nih.gov/health/acupuncture/ Get the Facts, Acupuncture], (2006). National Institute of Health. Retrieved on March 2, 2006.</ref>
 
==Epidemiology and demographics==
 
[[Image:wiki ibs prevalence.jpg|left|thumb|200px]]
 
'''By Country''': Studies have reported that the prevalence of IBS varies by country and by age range examined. The bar graph at right shows the percentage of the population reporting symptoms of IBS in studies from various geographic regions (see table below for references).
 
The following table contains a list of studies performed in different countries that measured the prevalence of IBS and IBS-like symptoms:
 
{| class="wikitable collapsible"
|-
! colspan="4" | Percentage of Population Reporting Symptoms of IBS in Various Studies from Various Geographic Areas
|-
|-
! Country
! Prevalence
! Author/Year
! Notes
|-
| Canada
| 6%<ref name="BOIVIN_2001">{{cite journal
| author =Boivin M.
| title =  Socioeconomic impact of irritable bowel syndrome in
| journal =Canada. Can J Gastroenterol.
| year =2001 Oct;15
| volume = Suppl B
| pages=:8B-11B. 
| id=PMID 11694908}} </ref>
| Boivin,2001
|
|-
| Japan
| 10%<ref name="QUIGLEY_2006">{{cite journal
| author =Quigley EM, Locke GR, Mueller-Lissner S, Paulo LG, Tytgat GN, Helfrich I, Schaefer E.  Prevalence and management of abdominal cramping and pain: a multinational survey. 
|title=Aliment Pharmacol Ther.
| year= 2006 Jul
| volume = 24
| issue=2
| pages=411-9
| id=PMID 16842469
| url=http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2036.2006.02989.x}} </ref>
| Quigley,2006
| Study measured prevalence of GI abdominal pain/cramping
|-
| United Kingdom
|  8.2%<ref name="EHLIN_2003">{{cite journal
| author =Ehlin AG, Montgomery SM, Ekbom A, Pounder RE, Wakefield AJ.
| title =  Prevalence of gastrointestinal diseases in two British national birth cohorts.
| journal =Gut.
| year =2003  Aug
| volume = 52
| issue=8
| pages=1117-21. 
| id=PMID 12865268}} </ref>
10.5%<ref name="WILSON_2004">{{cite journal
| author =Wilson S, Roberts L, Roalfe A, Bridge P, Singh S.
| title =  Prevalence of irritable bowel syndrome: a community survey.
| journal =Br J Gen Pract.
| year=2004
| volume = 54
| issue=504
| pages=495-502. 
| id=PMID 15239910}} </ref>
| Ehlin,2003
Wilson,2004
| Prevalence increased substantially 1970-2004
|-
| United States
| 14.1%<ref name="HUNGIN_2005">{{cite journal |author=Hungin AP, Chang L, Locke GR, Dennis EH, Barghout V |title=Irritable bowel syndrome in the United States: prevalence, symptom patterns and impact |journal=Aliment. Pharmacol. Ther. |volume=21 |issue=11 |pages=1365–75 |year=2005 |pmid=15932367 |doi=10.1111/j.1365-2036.2005.02463.x}}</ref>
| Hungin, 2005
| Most undiagnosed
|-
| United States
| 15%<ref name="BOIVIN_2001" />
| Boivin,2001
| Estimate
|-
| Pakistan
| 14%<ref name="JAFRI_2007">{{cite journal
| author =Jafri W, Yakoob J, Jafri N Islam M, Ali QM.
| title = Irritable bowel syndrome and health seeking behaviour in different communities of Pakistan.
| journal =J Pak Med Assoc.
| year =2007 Jun
| volume = 57
| issue=6
| pages=285-7
| id=PMID 17629228}} </ref>
| Jafri, 2007
| Much more common in 16-30 age range.  Of IBS patients, 56% male, 44% female
|-
| Pakistan
| 34%<ref name="JAFRI_2005">{{cite journal
| author =Jafri W, Yakoob J, Jafri N, Islam M, Ali QM. 
| title = Frequency of irritable bowel syndrome in college students.
| journal =J Ayub Med Coll Abbottabad.
| year =2005 Oct-Dec
| issue=17
| volume=4
| pages=9-11
| id=PMID 16599025 }} </ref>
| Jafri,2005
| College students
|-
| Mexico City
| 35%<ref name="SCHMULSON_2005">{{cite journal
| author =Schmulson M, Ortiz O, Santiago-Lomeli M, Gutierrez-Reyes G, Gutierrez-Ruiz MC, Robles-Diaz G, Morgan D.
| title = Frequency of functional bowel disorders among healthy volunteers in Mexico City.
| journal =Dig Dis.
| year =2006
| volume = 24
| oissue=3-4
| pages=:342-7
| id=PMID 16849861
| url=http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=92887&Ausgabe=231847&ProduktNr=224231&filename=92887.pdf}} </ref>
 
| Schmulson, 2006
| n=324.  Also measured functional diarrhea and functional vomiting.  High rates attributed to "stress of living in a populated city."
|-
| Brazil
| 43%<ref name="QUIGLEY_2006" />
| Quigley,2006
| Study measured prevalence of GI abdominal pain/cramping
|-
| Mexico
| 46%<ref name="QUIGLEY_2006" />
 
| Quigley,2006
| Study measured prevalence of GI abdominal pain/cramping
|-
|}
 
'''Returning Travelers''': A study of United States residents returning from international travel found a high rate of IBS and persistent diarrhea which developed during travel and persisted upon return.  The study examined 83 subjects in Utah, most of whom were returning missionaries.  Of the 68 who completed the gastrointestinal questionnaire, 27 reported persistent diarrhea that developed while traveling, and 10 reported persistent IBS that developed while traveling.<ref name="TUTEJA_2007">{{cite journal
| author =Tuteja AK, Talley NJ, Gelman SS, Adler SC, Thompson C, Tolman K, Hale DC.
E.
|title=Development of Functional Diarrhea, Constipation, Irritable Bowel Syndrome, and Dyspepsia During and After Traveling Outside the USA.
| journal=Dig. Dis. Sci
| year= 2007
| volume =
| issue=
| id=PMID 17549631
|}} </ref>
 
==Cost-effectiveness of therapy==
 
The aggregate cost of irritable bowel syndrome in the United States has been estimated at $1.7-$10 billion in direct medical costs, with an additional $20 billion in indirect costs, for a total of $21.7-$30 billion.<ref name="HULISZ_2004"> {{cite journal
| author = Hulisz D.
| title = The burden of illness of irritable bowel syndrome: current challenges and hope for the future.
| journal = J Manag Care Pharm.
| volume = 10
| issue = 4
| pages = 299-309
| year =2004
| id = PMID 15298528 
|}} </ref>  A study by a managed care company comparing medical costs of IBS patients to non-IBS controls identified a 49% annual increase in medical costs associated with a diagnosis of IBS.<ref name="LEVY_2001">{{cite journal
| author = Levy RL, Von Korff M, Whitehead WE, Stang P, Saunders K, Jhingran P, Barghout V, Feld AD.
| title = Costs of care for irritable bowel syndrome patients in a health maintenance organization
| journal = Am J Gastroenterol
| volume = 96
| issue = 11
| pages = 3122-9
| year =2001
| id = PMID 11721759
| }}  </ref> A 2007 study from a managed care oganization found that IBS patients incurred average annual direct costs of $5,049 and $406 in out-of-pocket expenses.<ref name="NYROP_2007">{{cite journal
| author Nyrop KA, Palsson OS, Levy RL, Korff MV, Feld AD, Turner MJ, Whitehead WE.
| title = Costs of health care for irritable bowel syndrome, chronic constipation, functional diarrhoea and functional abdominal pain.
| journal = Aliment Pharmacol Ther
| volume = 26
| issue = 2
| pages = 237-48
| year =2007
| id = PMID 17593069
| }}</ref>A study of workers with IBS found that they reported a 34.6% loss in productivity, corresponding to 13.8 hours lost per 40 hour week.<ref name="PARE_2006">{{cite journal |author=Paré P, Gray J, Lam S, ''et al'' |title=Health-related quality of life, work productivity, and health care resource utilization of subjects with irritable bowel syndrome: baseline results from LOGIC (Longitudinal Outcomes Study of Gastrointestinal Symptoms in Canada), a naturalistic study |journal=Clinical therapeutics |volume=28 |issue=10 |pages=1726–35; discussion 1710–1 |year=2006 |pmid=17157129 |doi=10.1016/j.clinthera.2006.10.010}}</ref> A study of employer-related health costs from a Fortune 100 company conducted with data from the 1990's found IBS patients incurred US $4527 in claims costs vs. $3276 for controls.<ref name="LEONG_2003">{{cite journal |author=Leong SA, Barghout V, Birnbaum HG, ''et al'' |title=The economic consequences of irritable bowel syndrome: a US employer perspective |journal=Arch. Intern. Med. |volume=163 |issue=8 |pages=929–35 |year=2003 |pmid=12719202 |doi=10.1001/archinte.163.8.929}}</ref> A study on Medicaid costs conducted in 2003 by the University of Georgia's College of Pharmacy and [[Novartis]] found IBS was associated in an increase of $962 in Medicaid costs in California, and $2191 in North Carolina.  IBS patients had higher costs for physician visits, outpatients visits, and prescription drugs.  The study suggested the costs associated with IBS were comparable to those found in asthma patients.<ref name="MARTIN_2003">{{cite journal |author=Martin B, Ganguly R, Pannicker S, Feride F;Barghout V|title=Utilization Patterns and Net Direct Medical Costs Medicaid of Irritable Bowel Syndrome |journal=Curr Med Res Opin|volume=19 |issue=8 |pages=771-780 |year=2003 |pmid=12719202 |url=http://www.medscape.com/viewarticle/465472}}</ref>
==Research spending on IBS==
 
{{Further|[[NIH funding of IBS Research]]}}
 
The [[National Institutes of Health]] provides a searchable database for grant awards since 1974 on its [[CRISP]] database, and provides dollar amounts for recent awards on its [http://grants.nih.gov/grants/award/trends/AggregateData.cfm Intramural Grant Award Page]. 
In 2006, the NIH awarded approximately 56 grants related to IBS, totalling approximately $18,787,710.
 
==Summary==
IBS does not lead to more serious conditions in most patients.<ref name="BERCIK_2005" /><ref name="QUIGLEY_2005" /><ref name="SIMREN_2002" /><ref name="MINDERHOUD_2004" /><ref name="GARCIA_2000" /> But it is a source of chronic pain, fatigue and other symptoms, and it increases a patient's medical costs,<ref name="NYROP_2007" /><ref name="LEVY_2001" /> and contributes to work absenteeism.<ref name="PARE_2006" /><ref name="MAXION_2006">{{cite journal |author=Maxion-Bergemann S, Thielecke F, Abel F, Bergemann R |title=Costs of irritable bowel syndrome in the UK and US |journal=PharmacoEconomics |volume=24 |issue=1 |pages=21–37 |year=2006 |pmid=16445300 |doi=}}</ref>  Researchers have reported that the high prevalence of IBS,<ref name="BOIVIN_2001" /><ref name="WILSON_2004" /><ref name="SCHMULSON_2005" /> in conjunction with increased costs produces a disease with a high societal cost.<ref name="HULISZ_2004" />
 
==References==
{{reflist|2}}
 
==External links==
*{{dmoz|Health/Conditions_and_Diseases/Digestive_Disorders/Intestinal/Irritable_Bowel_Syndrome/}}
*[http://www.InnateHealthFoundation.org The Innate Health Foundation - A public charity dedicated to supporting the IBS and food allergy communities]
*[http://digestive.niddk.nih.gov/ddiseases/pubs/ibs/ The US National Institutes of Health National Digestive Diseases Information Clearinghouse webpage for Irritable Bowel Syndrome]
 
<br>
 
{{Gastroenterology}}
 
[[de:Reizdarmsyndrom]]
[[es:Síndrome irritable de intestinos]]
[[fr:Côlon irritable]]
[[he:תסמונת המעי הרגיז]]
[[nl:Prikkelbare-darmsyndroom]]
[[pt:Síndrome do cólon irritável]]
[[ru:Синдром раздражённого кишечника]]
[[fi:Ärtynyt suoli]]
[[sv:IBS]]
[[pl:Zespół jelita drażliwego]]


[[Category:Gastroenterology]]
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[[Category:Ailments of unknown etiology]]
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Latest revision as of 22:26, 29 July 2020

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Synonyms and keywords: Spastic colon, functional bowel disorder, IBS

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