Mechanical Bowel Preparation: Are We Ready for a Paradigm Shift?

Abstract

which however actually did not happen. On the contrary, serious questions were raised on the accuracy of these RCTs. Unfortunately, none of these actually met the CONSORT guidelines completely. A historic meta-analysis by Bucher et al. [3] evaluating seven RCTs concluded that there was no evidence to support the use of MBP in patients undergoing elective colorectal surgery. Though it was the highest form of evidence, it was not devoid of technical errors and the outcome analysis was conflicting and incongruent. More recent multicentric randomized trials are better structured, however, and statistically robust. To name a few, a multicentric trial from Sweden which accrued 1,505 patients to give the study almost the desired power failed to demonstrate any significant benefit of MBP in reducing wound infection, overall infection and relaparotomy rate [4] . A systematic review by Guenaga et al. [5] done with meticulous selection of studies to prevent bias and type II error concluded that prophylactic MBP was not beneficial for the patients and controversially the bowel preparation might lead to more anastomotic leakage. Though it was not a part of consensus statement, the authors recommended such procedure should be omitted. In a multicenter randomized trial by Contant et al. [6] , the rate of anastomotic leakage did not differ significantly between with and without MBP groups (p ! 0.69). Although other septic complications, fascial dehiscence and mortality did not differ, those with MBP had fewer abscesses after anastomotic leakage (p ! 0.001). In another novel study, Colorectal surgery is still a challenge to the surgeon with respect to wound infection, intra-abdominal abscess and anastomotic leak. Since these complications are mainly caused by endogenous colonic bacteria, it was always thought logical that reducing the fecal load and bacterial count would reduce the rate of complications. This led to the concept of bowel antisepsis and cleansing in the 1940s and was accepted as a dogma in the 1970s. Since then various techniques of bowel preparation, the agents used and the modus operandi have changed many times. Such rapid changes indicate that either the surgeons are not uniformly happy with the procedure or are still looking for an ideal agent. Although traditionally mechanical bowel preparation (MBP) had its proposed advantages and shortcomings which were matter of some debate, its true role was never assessed through the eyes of evidence-based medicine. Hughes [1] (1972) was the first to challenge its longclaimed beneficial role when MBP was an incontestable routine. It was followed by a flurry of randomized controlled trials (RCTs) in the last two decades scrutinizing the role of MBP in elective colorectal surgery. Interestingly, all had concluded that MBP does not have any significant advantage in decreasing complications of colorectal surgery. Researchers went on further to prove that MBP actually increases infectious complications and anastomotic leaks and causes significant morphological and inflammatory changes in the colonic mucosa [2] . These were evidence enough to abandon it as a routine, Published online: September 26, 2008