[Electrical and motor activity of the rectum following low anastomosis]

Electrical and motor activity of smooth muscle of the canine rectum was registered by transanal recording following low rectum anastomosis. The relaxation reflex of the anal canal had disappeared distal of the anastomosis in the first postoperative week, and electrical slow waves and pressure waves were desynchronized proximal and distal of the anastomosis. The resting pressure of the rectal wall had increased above preoperative values. After wound healing had accomplished the relaxation reflex and the synchronization of electrical and mechanical activity proximal and distal of the anastomosis did occur again. It is concluded that the rectal wall provides the pathways for the relaxation reflex of the anal canal. After wound healing has finished these pathways are restored across the anastomosis.