Q- A 5-year-old boy is brought to the emergency department by his mother because of an episode of bloody stool 3 hours ago. The mother says the stool was hard “like pebbles” and she noted bright red blood on the tissue when the patient cleaned himself. His previous bowel movement was 5 days ago. The patient has no abdominal or rectal pain now, but he did have abdominal pain during his bowel movement 5 days ago. He has no history of major medical illness and receives no medications. Vaccinations are up-to-date. The patient has no recent history of travel. He is at the 5th percentile for height and the 10th percentile for weight; BMI is at the 50th percentile. Vital signs are within normal limits. Abdominal examination shows hypoactive bowel sounds and a soft, slightly distended abdomen that is not tender to palpation. Rectal examination shows 1 cm of bright red rectal mucosa protruding from the right side of the anus; there is no rectal bleeding. The remainder of the examination shows no abnormalities.
Which of the following is the most likely cause of this patient’s physical findings?
(A) Constipation
(B) Cystic fibrosis
(C) Hirschsprung disease
(D) Hookworm infestation
(E) Intussusception
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Answer and Explanation
The child has a history of infrequent, hard stools (last bowel movement 5 days ago, “pebble-like” stools). He experienced abdominal pain associated with defecation, which is a common symptom of constipation. The presence of bright red blood on the tissue suggests a rectal source of bleeding, likely due to anal fissures or rectal prolapse from straining. The physical exam reveals rectal mucosa protruding from the anus, suggesting rectal prolapse, a known complication of chronic constipation.
Cystic fibrosis: Can cause constipation due to meconium ileus in neonates or distal intestinal obstruction syndrome in older children, but it is often associated with failure to thrive, chronic respiratory infections, or steatorrhea.
Hirschsprung disease: Typically presents with failure to pass meconium in the neonatal period, chronic constipation, and abdominal distension, rather than isolated constipation in a 5-year-old.
Hookworm infestation: Causes chronic blood loss anemia but does not present with constipation or rectal prolapse.
Intussusception: Presents with intermittent, severe, colicky abdominal pain, lethargy, and “currant jelly” stools (mucus & blood), rather than chronic constipation and rectal prolapse.
The correct answer is A