1.   The compensatory response to extensive proximal small bowel resection includes growth of the remaining small intestine and of the gastric parietal cells, causing acid hypersecretion.

2.   Proximal small bowel resection had a clearcut effect on both absolute and relative pancreatic weight.

3.   Our results firmly implicate CCK as a key intermediary in the adaptive response of the pancreas to massive proximal small bowel resection.

4.   One patient had disease that seemed to be confirmed to the proximal small bowel.

5.   To protect the proximal bowel repeated colonoscopy may be required.