A Crohn disease patient presents with abdominal pain, vomiting, distension, hypotension, and decreased bowel sounds suggesting a small bowel obstruction. What is the most likely diagnosis?

• A. Perforated viscus
• B. Small bowel obstruction due to Crohn flare
• C. Mesenteric ischemia
• D. Acute pancreatitis

Answer: (D)

This item tests recognizing paralytic ileus from an inflammatory abdominal process rather than a pure mechanical blockage. When a patient with Crohn disease presents with abdominal pain, vomiting, abdominal distension, and decreased bowel sounds, it’s important to distinguish a true small-bowel obstruction from a generalized ileus.

Acute pancreatitis fits well here because it commonly causes vomiting and abdominal pain, and inflammation can lead to significant fluid shifts with third-spacing. Those fluid losses can drive hypotension. The bowel often becomes hypoactive, producing diminished or absent bowel sounds and distension not from a mechanical clamp but from reduced motility (ileus). In contrast, a mechanical small-bowel obstruction typically presents with crampy, intermittent pain, obstipation, and a more distinct pattern of bowel sounds that change from hyperactive to quiet as the obstruction progresses; perforated viscus would produce peritoneal signs, and mesenteric ischemia would usually present with severe pain out of proportion to exam and often occurs in patients with vascular risk factors rather than this described setting.

So the combination of pain with vomiting, distension, hypotension, and decreased bowel sounds aligns more with pancreatitis causing ileus than with a Crohn-related obstruction, making pancreatitis the most likely diagnosis in this scenario. Workup would include serum lipase and imaging to assess for pancreatitis and potential gallstone etiology, along with general fluid resuscitation and supportive care.