A 42-year-old woman with acute severe ulcerative colitis develops abdominal distension, fever, and tachycardia on day 3 of intravenous hydrocortisone. Abdominal radiograph shows a transverse colon diameter of 7.5 cm with mucosal islands. Bowel rest, nasogastric decompression, and broad spectrum antibiotics are already in place. What is the most appropriate next step?

• A Full colonoscopy with biopsies to assess mucosal healing
• B Barium enema to delineate the extent of dilatation
• C Urgent subtotal colectomy with end ileostomy ✓
• D Continue current therapy and reassess after two weeks

Explanation

Toxic megacolon is defined as colonic dilatation greater than 6 cm with systemic toxicity. Failure to improve within 48 to 72 hours of optimal medical therapy mandates urgent subtotal colectomy, because the mortality rises sharply once free perforation occurs. Full colonoscopy and barium enema are contraindicated in toxic megacolon since insufflation or filling can precipitate perforation. Two weeks of continued observation would be dangerously delayed given the dilatation and systemic signs.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.