Clinical reports on laparoscopic-assisted sigmoid colectomy (LASC) suggest that the period of postoperative inhibition of gastrointestinal motility is shortened as compared to open sigmoid colectomy (OSC). We aimed to specifically investigate whether colonic motility increases more rapidly following LASC compared to OSC. LASC was performed in 11 patients and OSC in nine patients for recurrent diverticulitis or carcinoma. During surgery a manometry catheter was inserted into the colon via the anus, and the tip was placed in the splenic flexure. Continuous manometric recordings were performed from the day of surgery until postoperative day 3 with a four-channel microtransducer manometry system combined with a portable data logger. The postoperative colonic motility index was 101+/-18, 199+/-30, and 163+/-27 mm Hg/min on days 1, 2, and 3 after LASC, respectively, which was increased compared to indexes of 53+/-15, 71+/-18, and 76+/-23 following OSC (mean+/-standard error of the mean; P<0.05). The amplitude but not the frequency of contractions was higher following LASC compared to OSC. Following LASC, patients requested a similar amount of pain medication but resumed oral food more rapidly on postoperative days 2 and 3 (P<0.05), and they were discharged from the hospital earlier (P<0.05). Colonic motility in particular and the patient's condition in general seem to improve more rapidly following LASC compared to the open procedure.