An infant with complete ileal resection and preserved ileocecal valve has which primary nutrition-related concern?

An infant with complete ileal resection and preserved ileocecal valve has which primary nutrition-related concern?

• A. Decreased vitamin B12 absorption
• B. Water-soluble vitamin malabsorption
• C. Dumping syndrome
• D. Protein malabsorption due to decreased cholecystokinin secretion

Answer: (A)

The key issue here is vitamin B12 absorption, which occurs in the terminal ileum as the B12–intrinsic factor complex is taken up by receptors there. If the ileum is completely removed, there is no site remaining to absorb B12, even if the ileocecal valve is preserved. The valve helps slow transit and limit bacterial overgrowth, but it does not provide an alternative absorption site for B12, so B12 deficiency becomes the primary nutrition-related concern. This can lead to macrocytic anemia and potential neurological problems if not addressed with B12 supplementation. Water-soluble vitamins are absorbed along the small intestine, not specifically dependent on the ileum, so they’re less immediately restricted by ileal resection. Dumping syndrome relates to rapid gastric emptying and is more of a GI motility issue than a direct consequence of ileal loss. Protein malabsorption due to decreased cholecystokinin secretion isn’t a primary consequence of removing the ileum; CCK is released in response to fat in the proximal small intestine and isn’t the main driver here.

The key issue here is vitamin B12 absorption, which occurs in the terminal ileum as the B12–intrinsic factor complex is taken up by receptors there. If the ileum is completely removed, there is no site remaining to absorb B12, even if the ileocecal valve is preserved. The valve helps slow transit and limit bacterial overgrowth, but it does not provide an alternative absorption site for B12, so B12 deficiency becomes the primary nutrition-related concern. This can lead to macrocytic anemia and potential neurological problems if not addressed with B12 supplementation.

Water-soluble vitamins are absorbed along the small intestine, not specifically dependent on the ileum, so they’re less immediately restricted by ileal resection. Dumping syndrome relates to rapid gastric emptying and is more of a GI motility issue than a direct consequence of ileal loss. Protein malabsorption due to decreased cholecystokinin secretion isn’t a primary consequence of removing the ileum; CCK is released in response to fat in the proximal small intestine and isn’t the main driver here.