Changes in motility after jejunal and ileal resection: electromyographic study in rats

The aim of this work was to compare the effects of massive jejunal and ileal resections on intestinal motility using an electromyographic technique. Male Wistar rats were used: in the first group a massive jejunal resection was performed, conserving a 7-cm segment after the ligament of Treitz; the rats of the second group underwent an ileal resection, preserving 7 cm of the terminal ileum. Motility was studied at the 10th and 30th postoperative days by means of electrodes implanted throughout the remaining bowel and was expressed by the pattern of recurrence of the migrating myoelectric complex (MMC). In a fasting state, in both transected and resected animals at the 10th postoperative day, the gradient in the duration of MMC along the intestine still existed. However, on the 30th postoperative day, in animals with jejunal resection only, there was an adaptive process: the duration of MMC in the remaining jejunum was significantly increased to the duration in the ileum. After the end of the postprandial inhibition of the appearance of the MMC, on the 10th postoperative day there was a significant decrease in the duration of MMC in the ileum in both types of resection, compared to the controls. However, on the 30th postoperative day, the duration of MMC returned to its control value. In conclusion, jejunal resection seems to induce more important adaptive processes in intestinal motility than does ileal resection. The different results are discussed.