How to confirm diagnosis of suspected ischemic colitis?

• A. CT angiography
• B. Barium enema
• C. Flexible sigmoidoscopy showing inflamed friable mucosa or full-thickness necrosis
• D. Abdominal ultrasound

Answer: (C)

The key idea is that confirming ischemic colitis relies on direct visualization and tissue assessment of the colon. Flexible sigmoidoscopy lets you inspect the distal colon where ischemic injury typically presents and observe specific mucosal changes—inflamed, pale, friable mucosa with possible erosions or ulcers; in more severe cases you may see necrosis. Taking biopsies during the procedure provides histologic confirmation, showing ischemic injury such as mucosal necrosis with hemorrhage and edema, while also helping to rule out infectious or inflammatory causes. This combination of visual findings and pathology is what makes the diagnosis definitive.

Imaging like CT angiography can help evaluate blood vessels and perfusion, especially to assess for mesenteric ischemia, but it doesn’t provide the direct mucosal confirmation that endoscopy does. A barium enema is not ideal in suspected ischemia because it can irritate and potentially worsen the condition and its findings are non-specific. Abdominal ultrasound lacks sensitivity for mucosal ischemic changes and isn’t the confirming test. In severe cases, signs of full-thickness necrosis on endoscopy signal a need for urgent surgical intervention.