Migrating action potential complexes in a patient with secretory diarrhea.

A 70-year-old woman with secretory diarrhea was studied with a novel technique of recording small intestinal myoelectrical activity which allowed us to obtain long, uninterrupted records of slow waves and spikes at eight or more different intestinal levels simultaneously. Typical migrating action potential complexes (MAPCs) were observed, consisting of spike bursts that extended over more than one slow wave and migrated distally at the same propagation velocity as the slow waves. This motility pattern occurred frequently during the period the patient presented with secretory diarrhea and disappeared with the disappearance of the diarrhea. It was observed only once in a series of 10 normal control subjects. This is the first report on MAPC activity in man and on the association of this myoelectrical pattern with secretory diarrhea in man.