The role of gastrointestinal hormones in the control of postprandial and interdigestive gastrointestinal function.

Gastric, pancreatic, biliary, and intestinal functions during interdigestive and postprandial periods can now be quantified and correlated with changes in gastrointestinal hormone concentrations. Through this type of study, we can begin to glimpse the physiological roles of gastrointestinal hormones. The segments of the gastrointestinal tract which regulate each digestive function can be determined by experimental manipulations in which postprandial chyme is diverted from or exposed to particular areas of the bowel through the use of occlusive balloons. These studies suggest that the upper gut is capable of regulating biliary and pancreatic function, while the stomach and the entire small bowel affect stomach function. In addition, gastric secretion is regulated more proximally than gastric emptying. Knowledge of the hormones present in different segments of the bowel permits hypothesis of their physiological regulatory functions.