Ileal resection can impair fat digestion due to a change in which pool?

• A. Decreased bile salts
• B. Increased bile salts
• C. No effect on bile salts
• D. Increased fat absorption

Answer: (A)

Fat digestion depends on bile salts to emulsify fats and form micelles for lipase action. The bile salt pool is maintained by enterohepatic circulation, with most bile acids reabsorbed in the terminal ileum and recycled to the liver. If the ileum is resected, reabsorption drops, shrinking the hepatic bile acid pool. With fewer bile salts available in the intestine, emulsification and micelle formation are impaired, leading to reduced fat digestion and fat malabsorption. Increased bile salts or no effect would not explain the problem, and increased fat absorption would be opposite to what happens.