Inflammatory Bowel Disease USMLE Step 1 Practice Question
A full-term male newborn presents with progressive abdominal distention and bilious vomiting; meconium has not been passed by 48 hours of life. Vital signs show HR 145/min, RR 38/min, and temperature 37.2°C. Physical examination reveals a distended abdomen; rectal examination causes explosive stool release. Abdominal X-ray demonstrates transition zone with proximal bowel dilation. There is no maternal polyhydramnios history. Rectal suction biopsy is most likely to show which of the following?
Answer choices
- ATransmural granulomatous inflammation
- BHypertrophy of the circular muscle layer of the pylorus
- CAbsence of ganglion cells in the submucosal and myenteric plexusesCorrect answer
- DEctopic pancreatic tissue in an ileal diverticulum
- EMucosal pseudopolyps limited to the rectum
- FIncreased acetylcholinesterase activity in the lamina propria and muscularis mucosae
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