Complications after colorectal surgery without mechanical bowel preparation

Background: The current practice of mechanical bowel preparation (MBP) before colorectal surgery is questionable. Mechanical bowel preparation is unpleasant for the patient, often distressful, and potentially harmful. The results are often less than desired, increasing the risk of contamination. Cleansing the colon and rectum before surgery has never been shown in clinical trials to benefit patients. In animal experiments MBP has a detrimental effect on colonic healing. Study design: To investigate the outcomes of colorectal surgery without MBP, we prospectively evaluated a consecutive series of patients who underwent resection and primary anastomosis of the colon and upper rectum, including emergency operations. One surgeon performed all operations. Endpoints were wound infection, anastomotic failure, and death. Late signs and symptoms that might be secondary to leakage of the anastomosis were considered as an anastomotic failure as well, during a followup of 1 year. Results: Two hundred fifty operations were performed, of which 199 (79.6%) were elective. Colectomies were left-sided in 65.6%. Anastomoses were ileocolic in 32%, colocolic in 20.8%, colorectal intraperitoneal in 34.4%, and extraperitoneal in 12.8%. No patient suffered from fecal impaction. Followup was complete in 97.2%. Eight patients (3.3%; 95% confidence interval [CI]: 1.4–6.4) developed superficial wound infections. In three patients there was leakage from an extraperitoneal colorectal anastomosis, in two of them after hospital discharge. The overall anastomotic failure rate was 1.2% (95% CI: 0.3–3.6). The in-hospital mortality rate was 0.8% (95% CI: 0.1–2.9) and was not related to abdominal or septic complications. Conclusions: Mechanical bowel preparation is not a sine qua non for safe colorectal surgery.