WBR0591

Author	[[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Yazan Daaboul, M.D.)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathology
Sub Category	SubCategory::Gastrointestinal
Prompt	[[Prompt::A 2-year-old boy is brought by his mother to the emergency department (ED) for new-onset nonbilious vomiting, severe colicky abdominal pain, and blood per rectum with stools. The mother reports that her child's stools have an unusual color and resemble currant jelly. The patient's past medical history is remarkable only for a recent upper respiratory tract infection and bilateral conjunctivitis. He was born by a normal vaginal delivery with an uneventful neonatal course. Physical examination in the ED is remarkable for an abdominal mass upon deep palpation of the right lower quadrant. Which of the following best describes the patient's condition?]]
Answer A	AnswerA::Circumferential infolding of the rectal mucosa
Answer A Explanation	AnswerAExp::Intussusception is characterized by the circumferential infolding of the rectal mucosa.
Answer B	AnswerB::Twisting of a portion of the bowel around its mesentery
Answer B Explanation	AnswerBExp::Volvolus is characterized by the twisting of a portion of the bowel around its mesentery
Answer C	AnswerC::Lack of ganglion cells of the enteric nervous plexus
Answer C Explanation	AnswerCExp::Hirschsprung's disease is characterized by the lack of ganglion cells of the enteric nervous plexus.
Answer D	AnswerD::Blind pouch that protrudes from the alimentary tract
Answer D Explanation	AnswerDExp::Diverticulum is characterized by the presence of a blind pouch that protrudes from the alimentary tract
Answer E	AnswerE::Submucosal inflammation with friable pseudopolyps
Answer E Explanation	AnswerEExp::Ulcerative colitis is characterized by the presence of submucosal inflammation with friable pseudopolyps on biopsy.
Right Answer	RightAnswer::A
Explanation	[[Explanation::The most common cause of small bowel obstruction in infants is intussusception. Intussusception is defined as the circumferential infolding of the rectal mucosa that is commonly present at the level of the ileocecal junction. It is a relatively common disease in the pediatric population that is characterized by the triad of nonbilious vomiting (that might become bilious in the case of complete obstruction), severe colicky abdominal pain, and currant jelly stools. Intussusception typically occurs following an upper respiratory tract infection, commonly an adenovirus infection (upper respiratory infection with bilateral conjunctivitis), similar to the patient's presentation. Physical examination may be remarkable for a palpable abdominal mass, commonly in the right lower abdominal quadrant side. Intussusception is considered an emergency and should be treated promptly, and air enema is considered both diagnostic and therapeutic. On the other hand, intussusception among the adult population usually prompts the investigation for a tumor that acts as a lead point for the infolding of the mucosa. Educational Objective: Intussusception is a pediatric emergency that is characterized by the circumferential infolding of the rectal mucosa. Symptoms include the triad of vomiting, colicky abdominal pain, and currant jelly stools. Air enema is both diagnostic and therapeutic. References: First Aid 2014 page 356]]
Approved	Approved::Yes
Keyword	WBRKeyword::Colicky, WBRKeyword::Abdominal, WBRKeyword::Pain, WBRKeyword::Vomiting, WBRKeyword::Nonbilious, WBRKeyword::Non-Bilious, WBRKeyword::Bilious, WBRKeyword::Currant, WBRKeyword::Jelly, WBRKeyword::Stools, WBRKeyword::Blood, WBRKeyword::Rectum, WBRKeyword::Pediatric, WBRKeyword::Rectal, WBRKeyword::Mucosa, WBRKeyword::Infolding, WBRKeyword::Intussusception
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