Our goal was to determine whether intestinal absorption could be enhanced by pacing the small bowel backward in dogs with the short bowel syndrome. In five dogs the aborad one third of the small bowel and the entire colon were removed, and an ileorectostomy was established. The small bowel and the entire colon were removed, and an ileorectostomy was established. The duodenum was transected and reanastomosed 10 cm from the pylorus to facilitate pacing, and cannulas were inserted in the intestine at 15, 110, and 115 cm for perfusion, sample collection, and balloon occlusion, respectively. Recording and stimulating electrodes were affixed to the bowel between perfusion and collection cannulas. In four or more trials in each dog, an isotonic perfusate of glucose (138 mM), NaCl (76 mM), and 3H-polyethylene glycol was introduced via the proximal cannula at 2.9 ml/min and effluent collected from the distal cannula for 3 hours. During hour 2, electrical stimuli were applied to the distal end of the perfused segment to drive the pacesetter potentials, hence contractions, of the perfused segment backward. Pacing decreased markedly the output of water, glucose, sodium, and potassium and increased the concentration of polyethylene glycol in the effluent. We concluded that retrograde electrical pacing increased small intestinal absorption of water, glucose, and sodium and decreased output of potassium in dogs with short bowel syndrome.