Ileal resection may lead to fat malabsorption due to depletion of which pool?

• A. Increased water absorption in the colon
• B. Bile salt pool is depleted and fat absorption is reduced
• C. Increased bile salt pool leading to improved fat absorption
• D. No effect on fat absorption

Answer: (B)

Fat absorption depends on bile salts to form micelles that solubilize fats for absorption in the small intestine. When ileal tissue is removed or bypassed, enterohepatic circulation of bile salts is disrupted, depleting the bile salt pool available to emulsify fats. With fewer bile acids available, micelle formation declines, fat is less efficiently emulsified and absorbed, leading to fat malabsorption after ileal resection. The colon’s water absorption isn’t the primary driver here, and increasing the bile salt pool would not occur if the ileum is resected; saying there’s no effect would be incorrect. In more extensive resections, fat-soluble vitamins may also be affected due to reduced fat absorption.