<i>Background:</i> At the beginning of 2004, a large Dutch randomized study comparing mechanical bowel preparation with a single preoperative enema reported no differences in anastomotic leakage rates, septic complications, or mortality. On the basis of this study, this institution abandoned the routine practice of bowel preparation with polyethylene glycol and introduced a single preoperative enema. <i>Methods:</i> A consecutive series of 78 patients undergoing elective colorectal surgery with mechanical bowel preparation using polyethylene glycol (PG group) was compared to a consecutive series of 71 patients with a single preoperative enema (SE group). The PG group was operated between June 2003 and December 2004, the SE group between January 2005 and January 2006. Mortality, anastomotic leakage, and infectious and noninfectious complications were compared. <i>Results:</i> Mortality, anastomotic leakage, frequency of reoperations, and hospital stay were comparable for both groups. The overall postoperative morbidity was significantly higher in the SE group (26 vs. 9, p = 0.003). Specifically, the incidence of wound infections was significantly higher in the SE group (7 vs. 1, p = 0.041). Furthermore, a trend was observed in the incidence of intra-abdominal infections which was higher in the SE group (8 vs. 2, p = 0.070). Also a trend toward more extra-abdominal infectious complications was seen in the SE group (11 vs. 4, p = 0.086). <i>Conclusions:</i> Based on both the conflicting data currently available from different randomized studies and our results, the preoperative bowel preparation protocol in our institution has been changed. All left-sided colonic resections, in patients who can tolerate mechanical bowel preparation, are prepared with polyethylene glycol.