PURPOSE: Although most randomized trials demonstrated no advantage of mechanical bowel preparation for colorectal resection, an oral solution is still widely used. The aims of this study were to evaluate whether a single phosphate enema is as effective as oral polyethylene glycol (PEG) solution in preventing anastomotic complications after laparoscopic colorectal surgery and to examine the clinical courses of anastomotic complications. METHODS: Between September 2006 and December 2007, 309 patients underwent laparoscopic colorectal resection with primary anastomosis. The bowel preparation used was PEG solution during initial period (PEG group), but since February 2007, a single phosphate enema (enema group) was utilized. Postoperative data were prospectively recorded. In patients with anastomotic complications, the clinical course was compared between the two groups. RESULTS: There were 150 patients in the PEG group and 159 patients in the enema group. Demographics did not differ between the two groups. Anastomotic leakage occurred in 3.3 percent of the patients in the PEG group and 5.7 percent of the patients in the enema group (P=0.326). The rates of anastomotic bleeding were 2.0 and 2.5 percent, respectively (P=0.761). The hospital stays for patients with anastomotic complication were not different between the two groups (P=0.137), but patients in the PEG group (80%) needed reoperation more frequently than those in the enema group (11.1%) (P=0.023). CONCLUSION: These results suggest that laparoscopic colorectal surgery may be safely performed with a single phosphate enema instead of oral polyethylene glycol.