Gastrointestinal myoelectric activity in fasting and nonfasting canine models of ileus

We studied postoperative gastrointestinal (GI) tract myoelectric activity (MEA) in three fasting and nonfasting models of ileus. After implantation of a gastric cannula and bipolar electrodes in the antrum, duodenum, proximal jejunum, midjejunum, terminal ileum, and ascending and descending colon, five dogs underwent ileus-producing laparotomies, including handling, in which the entire GI tract was manually crushed, obstruction, in which a distal ileal obstruction was created and released 24 hours later, and peritonitis, in which an ileal perforation was created and closed 24 hours later. The fasting 24-hour postoperative colonic MEA in the handling and obstruction models was significantly less than control levels but returned to normal by 48 hours. The nonfasting 24-hour postoperative duodenal and jejunal MEA in the obstruction model was significantly less than control levels. These significantly decreased MEA levels persisted for 72 hours. Nonfasting 24-hour postoperative ileal and colonic MEA in the peritonitis model was significantly greater than control levels and remained significantly elevated for 48 to 72 hours before returning to normal.