Large bowel myoelectrical activity in man

SUMMARY The myoelectrical activity of human colon and rectum has been studied by three types of electrode in man-intraluminal (suction), serosal and cutaneous. The patterns obtained indicate a high degree of consistency between the methods and the value of surface electrodes is emphasized. Gradients along the large bowel of both frequency and percentage electrical activity have been observed and possible physiological roles are postulated for them. By correlating the features of regular electrical and corresponding regular motor waves an alteration in the myoelectrical pattern is observed in the region of the rectosigmoid junction. The main electrical wave form detected in the smooth muscle of the stomach and small bowel is known as the slow wave or basic electrical rhythm and is present all the time. Slow waves are thought to coordinate gastrointestinal motility and their characteristics have been described both in vivo and in vitro (Daniel, Wachter, Honour, and Bogoch