Postoperative intestinal motility in dogs and sheep.

Electrical activity of the small intestine was recorded from chronically implanted electrodes in dogs and sheep. The effects of laparotomy and surgical procedures were identified under general anesthesia. Laparotomy induced in both species a complete inhibition of electrical spiking activity during the stage of muscular and peritoneal incision. The inhibitory period due to laparotomy was shorter in dogs than in sheep and in both species less marked at the duodenal level. A secondary period of inhibition (ileus) lasting from 6 hr for a resection of the colon to 24 hr for a transection of the small bowel was observed in dogs after a transient phase of normal activity during 3-6 hr. The period of inhibition due to abdominal surgery lasted from 48 to 72 hr and occurred at the time of surgery in sheep. In both species, inhibition due to laparotomy and surgical procedures was prevented by splanchnicectomy. The results showed that myoelectric activity of the different parts of the small intestine is specifically inhibited and/or disorganized through peripheral reflex pathways. They are activated at different degrees by laparotomy and abdominal surgery.