What is the role of mechanical bowel preparation in patients undergoing colorectal surgery?

BACKGROUND: Most surgeons use mechanical bowel preparation before performing operations on the colon and rectum. The aim of this study is to determine if there is any published literature that supports this practice.
METHODS: We undertook a review of the literature on the benefits of mechanical bowel preparation in patients undergoing surgery on the colon and rectum. A meta-analysis was conducted on all available clinical trials addressing this issue.
RESULTS: A meta-analysis of three clinical trials revealed a significantly greater incidence of wound infection in patients who received a mechanical bowel preparation (10.8 vs. 7.4 percent; P < 0.002; 95 percent confidence interval of the difference, -1.6-8.4 percent). Patients who received mechanical bowel preparation had an incidence of anastomotic leakage that was twice that of control patients; however, this difference was not significant (8.1 vs. 4 percent; P < 0. 1 14; 95 percent confidence interval of the difference, -0.4-8.4 percent).
CONCLUSION: There is limited evidence in the literature to support the use of mechanical bowel preparation in patients undergoing colorectal surgery. Hence, there is a need for clinical trials comparing the more traditional, aggressive forms of bowel preparation (e.g., polyethylene glycol solutions, sodium phosphate) with either no preparation or simpler techniques, such as a single phosphate enema.