Change in colonic motility after extrinsic autonomic denervation in dogs.

Changes in colonic motility were compared in dogs undergoing autonomic denervation of the paraaortic and presacral (group A), paraaortic (group B), or mesocolonic region (group C), and sham operation (group D). Five bipolar recording electrodes were placed into the seromuscular layer of the colon and rectum. The numbers of continuous electrical response activity and contractile electrical complex after an intragastric olive oil injection were smaller in group A than in the other groups (P < 0.05) from three weeks through six months after denervation. This difference was significant even in the proximal colon. These data suggest that the pelvic plexus may play an important role in colonic motility including the proximal colon. The damage to the plexus did not recover for at least six months after denevation. Pelvic plexus injury may thus be one of possible explanations for the prolonged change in bowel habit after anterior resection of the rectum.