Increased Plasma Levels of Pancreatic Polypeptide and Decreased Plasma Levels of Motilin in Encopretic Children

Objective. Abnormalities of hormones affecting gastrointestinal motility have been found in "functional" disorders of the gastrointestinal system in adults. One such disorder of childhood, encopresis, is frequently associated with constipation, the treatment of which often eliminates the soiling. We hypothesized that hormones affecting gastrointestinal motility were different between encopretic patients and matched controls. Methods. Ten encopretic patients were matched by age, race, and sex with controls who had no history of encopresis or constipation. After an overnight fast, each child consumed a meal of Ensure, the amount of which was based on body weight. Plasma levels of gastrin, pancreatic polypeptide, cholecystokinin, motilin, thyroxine, estrogen, and insulin were measured 20 and 5 minutes before the meal, and 5, 10, 15, 30, 45, 60, 90, 120, 150, and 180 minutes after the meal. Results. Postprandial levels of pancreatic polypeptide remained consistently higher and peaked earlier (P < .05) for encopretic patients. The motilin response was lower (P < .03) for encopretic children than for controls. Conclusions. We conclude that pancreatic polypeptide and motilin responses to a meal are different in encopretic children than in children in the control group. These gastrointestinal hormone findings may in part explain and/or be the result of the severe constipation that frequently underlies the fecal soiling found in these patients. These findings also suggest the motility of the stomach and small intestine may be abnormal in encopresis.