Does Mechanical Bowel Preparations really prevent infective complications after colorectal surgery? Is a Myth or Fact? Mechanic Bowel Preparations: Is a Myth or Fact?

Abstract Purpose: Despite mechanical bowel preparation (MBP) was routinely used before elective colorectal surgery in most of surgical clinics, using MBP remains controversial. This study aimed to investigate the postoperative infectious complications and outcomes of right, left or rectosigmoid resection without MBP and compare with each other.Methods: Patients who underwent elective colorectal surgery without mechanical bowel preparation between January 2011 and December 2021 were included in the study. Patients were categorized according to the side of resection (right, left and rectosigmoid resection), and these subgroups compared for the anastomotic leakage and surgical site infections (SSI) and overall morbidity measured using the Clavien-Dindo classification Results: The data of 422 patients who met the study criteria were analyzed. There were 152 (36%) patients in the right colectomy group, 106 (25.1%) patients in the left colectomy group, and 164 (38.9%) patients in the rectosigmoid resection group. Overall anastomotic leakage was found in 14 (3.3%), SSI was in 46 (10.9%), the collection was in 14 (3.3%), mortality was 18 (4.3%), and reoperation was in 17 (%4) patients. Anastomotic leakage was observed in 6 (3.9%) in the right colectomy, 2 (1.9%) in the left colectomy, and 6 (3.7%) patients in the rectosigmoid resection group when the groups were evaluated separately. There was no statistical difference between the groups (p=0.630). Considering the mortality rates, it was found to be higher in the right colectomy group compared to the other groups, and the p value was 0.003. Furthermore, there was no statistical difference between the groups regarding collection, and reoperation; p values were p=0.31, and p=0.251, respectively.Conclusion: There was no increase in anastomotic leakage, surgical site infection, intra-abdominal collection, reoperation, and mortality rates in patients undergoing colorectal surgery without MBP. In addition, these results were not changes for right, left or rectosigmoid resection sub-groups.