Which segment of the small intestine has greater adaptive capacity after resection?

• A. Duodenum
• B. Jejunum
• C. Ileum
• D. Cecum

Answer: (C)

Adaptive capacity after resection depends on how well the remaining bowel can remodel and take over lost absorptive functions. The distal ileum has the strongest ability to do this. It responds to feeding with marked mucosal growth—villus height and crypt depth increase—expanding the absorptive surface. Hormonal signals from the distal gut, especially GLP-2, promote this mucosal adaptation, making the ileum particularly capable of compensating for losses by increasing absorption of nutrients, bile acids, and vitamin B12 when portions are removed or other segments are stressed. The duodenum is relatively fixed in form and short, so its capacity to enlarge surface area is limited; the jejunum can adapt but generally not to the same extent as the ileum. The cecum isn’t part of the small intestine, so it doesn’t apply here. Therefore, the segment with the greatest adaptive capacity after resection is the ileum.