Stimulation of the pancreatic secretion of water, electrolytes, and enzymes is under neurohumoral control sensitive to the ingestion and digestion of food. Hormones interact to maximize physiologic responses to a meal and to autoregulate pancreatic secretion. Clinical manifestations of pancreatic exocrine insufficiency may result from obstruction to pancreatic flow through the major duct or to destructive disease of the exocrine cells; this insufficiency is a consequence of reduced volume, electrolytes, and enzyme output.