Chronic diarrhea laboratory findings
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Omodamola Aje B.Sc, M.D. [2]
Overview
The laboratory findings in chronic diarrhea include complete blood count to evaluate for anemia, abnormal white blood cell count, electrolytes, thyroid tests, serological tests for celiac disease and stool analysis for fecal leukocytes, fecal lactoferrin, fecal occult blood.
Laboratory Findings
Blood Tests
Initial laboratory tests should include a complete blood count to evaluate for anemia and an abnormal white blood cell count, as well as electrolytes, thyroid tests, and serological tests for celiac disease. [1][2][3][4]
Stool Analysis
- Fecal leukocytes; the presence of white blood cells in the stool has a sensitivity of 70% and a specificity of 50% for detecting inflammation in studies of infectious diarrhea. Fecal white blood cells can be present in both infectious colitis and inflammatory bowel diseases such as ulcerative colitis, Crohn’s disease, and microscopic colitis.
- Fecal lactoferrin; this is an iron-binding glycoprotein that is a major component of the secondary granules of polymorphonuclear neutrophils and is secreted by most mucosal membranes. Fecal lactoferrin levels have never been evaluated in the workup of chronic diarrhea.
- Fecal occult blood; the sensitivity and specificity of stool guaiac cards for detecting inflammatory or neoplastic causes of diarrhea have not been studied.
- Stool electrolytes
Measuring stool potassium and sodium concentrations can determine the stool osmotic gap. For secretory diarrhea, the osmotic gap is less than 50 mOsm/kg. In osmotic diarrhea, the osmotic gap is greater than 50 mOsm/kg.
References
- ↑ Fine, K; Schiller, L (1999). "AGA Technical Review on the Evaluation and Management of Chronic Diarrhea☆". Gastroenterology. 116 (6): 1464–1486. doi:10.1016/S0016-5085(99)70513-5. ISSN 0016-5085.
- ↑ "American Gastroenterological Association medical position statement: Guidelines for the evaluation and management of chronic diarrhea☆, ☆☆". Gastroenterology. 116 (6): 1461–1463. 1999. doi:10.1016/S0016-5085(99)70512-3. ISSN 0016-5085.
- ↑ Camilleri M (2004). "Chronic diarrhea: a review on pathophysiology and management for the clinical gastroenterologist". Clin Gastroenterol Hepatol. 2 (3): 198–206. PMID 15017602.
- ↑ Fine KD, Seidel RH, Do K (2000). "The prevalence, anatomic distribution, and diagnosis of colonic causes of chronic diarrhea". Gastrointest Endosc. 51 (3): 318–26. PMID 10699778.