Changed integrated gastrointestinal response to a mixed meal in exocrine pancreatic insufficiency

Using a multiple-marker dilution technique to quantitate flow volumes at a jejunal sampling site 70 cm from pylorus, propulsion and absorption of a 300-ml mixed liquid test meal were compared in seven patients with exocrine pancreatic insufficiency and in ten healthy subjects. In pancreatic insufficiency, outputs of lipase and amylase were 8% of control levels. Early gastric emptying rate was similar in both groups, but emptying was completed earlier, and less gastric acid was emptied in pancreatic insufficiency. In pancreatic insufficiency, initial biliary output was larger than in controls, and transit time through the test segment was twice that of controls. During the prolonged transit time, larger amounts of glucose (but less fat) were absorbed in pancreatic insufficiency. Forty minutes after the meal, almost a third of the fatty content of the meal was propelled to lower parts of the intestine. In conclusion, pancreatic insufficiency is associated with impaired inhibitory regulation of gastric and biliary outputs after a mixed meal. The impaired digestion of nutrients in pancreatic insufficiency is partially compensated for by slowing of intestinal transit, permitting more efficient absorption. Exposure of the gut to large quantities of fat is suggested to trigger the slowing of upper intestinal transit in pancreatic insufficiency.