In addition to bile salt malabsorption, cholestyramine can be used with antidiarrheal agents in which clinical scenario?

• A. To manage ulcerative colitis
• B. After extensive bowel resection
• C. To treat dehydration
• D. For infectious diarrhea

Answer: (B)

Cholestyramine works by binding bile acids in the gut, preventing their reabsorption and reducing the colonic irritation and secretory diarrhea they cause. After extensive bowel resection, especially when the ileum is involved, the ability to reabsorb bile acids is greatly diminished, leading to bile acid–driven diarrhea. In this scenario, combining a bile acid sequestrant with an antidiarrheal helps address two mechanisms at once: the excess bile acids that stimulate secretion and motility, and the overall reduced intestinal transit time controlled by the antidiarrheal. The other situations listed don’t primarily involve bile acid–driven diarrhea, so cholestyramine is not as beneficial there.