Pacing the canine ileostomy.

The aim of this study was to determine whether retrograde electric pacing of a 50 cm isoperistaltic duodenal segment transposed to a location 30 cm proximal to the stoma would provide continence and improve absorption in dogs with incontinent ileostomies. In five ileostomy dogs with transposed duodenal segments, electrodes were applied to the segments for monitoring electric activity and for pacing the segments in a backward or orad direction at will. After recovery, each of the fasted, conscious dogs underwent four control and four pacing experiments during which ileostomy output and enteric transit and absorption were monitored for 9 hours after a meal of 200 gm of technetium-99m-labeled liver and 50 ml of polyethylene glycol-labeled water. In pacing experiments the pacesetter potentials of the transposed segment were driven backward by pacing during the first 3 postcibal hours. Pacing markedly slowed gastrointestinal transit of both liquid and solid and decreased output from the stoma during the pacing period, thus changing an incontinent ileostomy into a more continent one. Output was only 9 +/- 3 ml/hr (mean +/- SEM) during pacing, compared with 19 +/- 3 ml/hr without pacing (p = 0.01). Pacing, however, did not improve overall enteric absorption after the meal. In conclusion, pacing a duodenal segment transposed to a preileostomy location slowed intestinal transit and converted an incontinent ileostomy into a more continent one, but it did not improve overall intestinal absorption.