Pressure responses of canine ileocolonic junctional zone to intestinal distention

Abstract

The purpose of this investigation was to study the effects of transient intestinal distention on pressures in the ileocolonic junctional zone of dogs. A fluid-filled, radiopaque, 5 x 20-mm recording balloon, from which pressures could be transmitted via a polyethylene tube to a transducer and recorded photokymographically, was positioned fluoroscopically through fistulas in the cone-shaped structure denoting the point of confluence of the barium-filled small and large bowel in 4 conscious, fasted animals. Stimulation was produced by infalting a miniature distending balloon in the ileum (131 times) or colon (88 times). Mean junctional area pressure prior to stimulation was 66 SEM[plus or minus] 2.2 cm H2O above ambient. A decline in pressure interpreted as relaxation was the most common junctional zone response to ileal stimulation by distention. This was frequently followed by a pressure increase indicating contraction. Contraction alone was more common with colonic distention whereas relaxation was infrequent. Despite the pressure changes, no alteration in the X ray configuration of the junction occurred with either small or large bowel distention.