Introduction: Clinical observations suggest that postoperative gastrointestinal motility disorders are attenuated following laparoscopic-assisted compared to open sigmoid colectomy (Dis Colon Rectum 2000: 45; 61). We aimed to investigate whether postoperative colonic motility is increased following laparoscopic-assisted sigmoid colectomy compared to the conventional operation. Methods: 11 patients (median age 63 years; range 48-79) underwent laparoscopic-assisted sigmoid colectomy for recurrent diverticulitis (n=8) or carcinoma (n=3). 9 patients (median age 61; 38-74 years) had open sigmoid colectomy for recurrent diverticulitis (n=4) or carcinoma (n=5). Postoperative colonic motility was recorded by a 4-channel microtransducer manometry system combined with a portable data logger (Standard Instruments, Karlsruhe, Germany). The recording catheter was inserted during surgery via the anus following the completion of the anastomosis. The tip of the catheter was placed in the splenic flexure. Continuous manometry recordings were performed from 6 p.m. on the day of surgery until the 3rd postoperative day. Recordings were evaluated blinded in 3 sequential recording periods, each consisting of 24 hour. Statistical comparison was performed by two-way ANOVA. Data are mean+/-SEM. Results: Data of colonic motility index are given in the table (mmHg per min). Two-way ANOVA demonstrated a significant influence of the operative technique on the postoperative motility index (p<0.05) and the mean amplitude (p<0.001) but not the mean frequency of contractions (n.s.). Conclusions: Following laparoscopic-assisted sigmoid colectomy colonic motility appears to be increased compared to the open operation. This may explain the previously described earlier recovery of normal gastrointestinal function in patients following the laparoscopic approach.