Chagas' disease: a model of denervation in the study of digestive tract motility.

The enteric nervous system (ENS) is an important neural network that integrates, modulates and coordinates various motor functions of the digestive tract. Chagas' disease, to a variable extent and in a nonsystematic way, causes destruction of ENS neurons throughout the digestive tract. The studies carried out on the pathophysiology of the digestive form of this disease have provided, as a corollary, a better understanding of the participation of the ENS in the regulation of the normal motor activities of the digestive tract and have led to the conclusion that the disease is a true model of intrinsic denervation of the human digestive tract. Among the motor alterations caused by impairment of the digestive tract in Chagas' disease are: absence of peristalsis in the esophagus, achalasia of the cardia, loss of the accommodation reflex in the proximal stomach, gastric emptying disorders, changes in the migrating motor complex (MMC), disappearance of postprandial motor phenomena in the colon and rectum, lack of relaxation of the internal sphincter of the anus, and anomalous responses of the gall bladder to cholekinetic stimuli.