PURPOSE: The aim of this study was to compare the length of postoperative ileus in patients undergoing colectomy by either laparotomy or laparoscopy. METHODS: A total of 166 patients were studied. These patients were divided into two groups: Group 1, in which colectomy was done laparoscopically, and Group 2, consisting of patients undergoing laparotomy. Both groups contained 83 patients who were matched for disease severity, indications for surgery, and procedure. Indications for surgery included sigmoid diverticulitis in 12 (14 percent) patients, polyps in 22 (27 percent), Crohn's disease in 21 (25 percent), colorectal cancer in 11 (13 percent), stoma reversal in 8 (10 percent), rectal prolapse in 3 (4 percent), and other indications in 6 (7 percent) in each group. Operations were colectomy with anastomosis (42 ileocolic, 26 colorectal, 6 colocolic, 4 ileorectal, and 2 ileal J pouch) or without anastomosis (3 abdominoperineal resections) performed by the same surgeons during the same time period (January 1993 to October 1996). The nasogastric tube was removed from all patients immediately after surgery in both groups. All patients received a clear liquid diet on the first postoperative day, followed by a regular diet as tolerated. The nasogastric tube was reinserted if two or more episodes of emesis of more than 200 mi occurred in the absence of bowel movement. Patients were discharged from the hospital when tolerating a regular diet without evidence of ileus. Statistical analysis was performed using unpaired t-test and Fisher's exact probability test. RESULTS: The male-to-female ratio was 38 to 45 in both groups. A total of 10 (12 percent) and 23 (28 percent) patients in Group 1 and Group 2 had emesis (P = 0.02), and the rate of nasogastric tube reinsertion was 5 (6 percent) and 13 (16 percent), respectively (P > 0.05). There were significant differences between Groups 1 and 2 relative to the lengths of ileus (3.5 +/- 1.3 vs. 5.4 +/- 1.7 days, respectively, P < 0.001), hospitalization (6.6 +/- 3.3 vs. 8.1 +/- 2.5 days, respectively; P < 0.002), and operative time (170 +/- 60 vs. 114 +/- 46 minutes, respectively; P < 0.001). The morbidity rate was 16 (19.2 percent) and 18 (21.6 percent) in the laparoscopy and laparotomy groups, respectively. CONCLUSIONS: Although early oral intake is safe and can be tolerated by 84 percent of patients after colectomy by laparotomy, laparoscopic colectomy reduced the lengths of both postoperative ileus and hospitalization.