Human Rectosigmoid Electromyography: A New Approach and Some Pitfalls

A method has been developed to record directly myoelectrical activity from the smooth muscle of the colon of intact subjects using pairs of intramuscular wires. Discrete bursts of myoelectrical activity occurred at 4–20 per min. A small interelectrode distance in this method allows contamination of colonic myoelectrical activity by the electromyogram of skeletal muscle to be excluded. This artefact has not been considered in previous recordings of ‘colonic’ activity.