In Crohn disease presenting with signs of small bowel obstruction, what is the most likely cause of the obstruction?

• A. Adhesions
• B. Gallstone ileus
• C. Volvulus
• D. Crohn flare

Answer: (D)

In Crohn disease, the small-bowel obstruction is most often caused by the inflammatory process itself. An active Crohn flare leads to edema, thickening of the bowel wall, and sometimes fibrosis, all of which narrow the lumen and impede passage of contents. Over time, chronic inflammation can create fixed strictures, again causing obstruction.

Adhesions are a frequent cause of SBO in patients with prior abdominal surgery, but in someone with Crohn disease, the immediate obstruction is more likely due to the active inflammatory changes of the disease itself. Gallstone ileus and volvulus can cause obstruction, but they are not specifically tied to Crohn disease and are less likely the explanation in this clinical context.