We designed a conscious pig model to investigate myoelectric activity and the number of interstitial cells of Cajal (ICC) in the proximal jejunum following the Roux-en-Y and 'uncut' Roux procedures in relation to clinical outcomes. Twelve male Polish White pigs (8 weeks old, 10-13 kg) underwent surgery under general anaesthesia first to implant bipolar electrodes and telemetry transmitters for continuous electromyography recordings and then, after 1 week recovery, to create Roux-en-Y (n = 6) and 'uncut' Roux loops (n = 6). Upper gut tissue specimens were studied for the expression of c-kit staining procedure to quantitatively identify the presence of interstitial cells of Cajal. The intestinal migrating motor complex was restored within 10.5 and 37 h in 'uncut' Roux and Roux-en-Y pigs, respectively (P < 0.05). During 2 weeks, the 'uncut' Roux piglets increased their body weight by 18.0%, whereas the Roux-en-Y piglets increased their body weight by only 7.3% (P < or = 0.05). Two weeks after surgery, the number of ICC located in the region of Auerbach's plexus was higher and adhesions in the abdominal cavity lower in the 'uncut' Roux group. In conclusion, in the pig model, preservation of smooth muscle and ICC network continuity in the proximal jejunum may play an important role in early postsurgical recovery.