Why does resection of the ileocecal valve result in malabsorption?

• A. Increases transit time preventing absorption
• B. Decreases pancreatic enzyme activity
• C. Decreases transit time and influx of nutrients to colon causing malabsorption
• D. Increases gastric acid production

Answer: (C)

Removing the ileocecal valve changes both the timing and flow of intestinal contents. That valve normally slows transit from the ileum to the colon and helps limit backflow of colonic contents into the ileum. When it’s gone, contents move more quickly into the colon, so there’s less contact time in the ileum for absorption and more nutrients and substrates reach the colon. This accelerated transit reduces absorption of many nutrients and bile acids in the distal small intestine, and the increased arrival of undigested material in the colon fosters bacterial overgrowth and fermentation, which further impairs absorption and can cause osmotic diarrhea.