Simultaneous recording of myoelectrical activity and resistance from the human colon.

A system used to record myoelectrical activity from the rectosigmoid colon has been modified so that a continuous recording of electrical resistance is obtained simultaneously. Normal subjects, patients with diverticular disease and patients with the irritable colon syndrome have been studied by this method. There were variations in resistance in the form of waves for 74.7, 88.5 and 89.0% of the time in the three groups. These changes were abolished by intravenous glucagon. The predominant frequency of the waves was 2-4 c/min and often coincided with myoelectrical waves of the same frequency. It is concluded that the resistance changes are produced by local movement in the colonic wall at the electrode site and that this technique may be valuable in studying colonic motility.