In ulcerative colitis, what risk is associated with excessive use of diphenoxylate (Lomotil)?

• A. Toxic megacolon
• B. Appendicitis
• C. Dehydration
• D. Seizures

Answer: (A)

In ulcerative colitis, using diphenoxylate (Lomotil) excessively can dangerously slow the bowel and allow the colon to become massively distended. Diphenoxylate is an opioid-like antidiarrheal that reduces intestinal motility; in an inflamed colon, this can lead to gas and stool buildup, resulting in toxic megacolon, a life-threatening dilation of the colon with systemic toxicity. This scenario is the main risk because it directly stems from suppressing colonic movement in a diseased colon, whereas dehydration is a broader consequence of diarrhea and seizures aren’t a typical risk with standard use. Appendicitis isn’t linked to this medication, so it doesn’t fit the specific danger posed by overuse in ulcerative colitis.