Gastric secretion and serum gastrin in human small bowel bypass

Jejunolieal bypass (JIB) patients provide a unique opportunity to study the relationship between small bowel loss and gastric secretory function. Preoperatively, and approximately one year postoperatively, measurements of gastric secretion were taken in 37 patients who underwent JIB for massive obesity. Basal acid output increased by 0.52 plus or minus 0.35 mEq/hr (P greater than.2), and peak stimulated acid output increased by 1.99 plus or minus 0.96 mEq/30 min (P smaller than .05). A separate group of 26 postoperative and 17 preoperative (control) JIB patients had fasting serum gastrin levels measured by radioimmunoassay. Postoperative patients had levels of 37 plus or minus 5 pg/ml, and control patients had levels of 36 plus or minus 4 pg/ml (P greater than .5). We conclude that following JIB for obesity, there is no significant change in basal acid secretion or in serum gastrin. There is a small, but statistically significant, increase in peak stimulated acid output. We currently find no clinical correlation with this change.