BACKGROUND: Bowel preparation has long been used to prevent infectious complications and facilitate easy colorectal surgery. Both mechanical and oral antibiotic bowel preparation have been thoroughly studied in the elective colorectal resection population, but no studies exist on their use before adult colostomy reversals. This study aims to evaluate the effect of preoperative bowel preparation on anastomotic leak and infectious complication rates after colostomy reversal surgery. METHODS: Retrospective cohort analysis of the 2016-2020 American College of Surgeons National Surgical Quality Improvement Program colorectal-specific database was performed. Adults who underwent elective colostomy reversal were stratified into 4 groups: no bowel preparation, oral antibiotic only, mechanical bowel preparation only, or combined oral antibiotic + mechanical bowel preparation. Outcomes measured were infectious complications, anastomotic leak, prolonged ileus, wound disruption, acute kidney injury, Clostridium difficile colitis, return to the operating room, survivor-only length of stay, mortality, and unplanned readmissions. Logistic regression analyses were performed to identify predictors of infectious complications and anastomotic leak. RESULTS: A total of 793 patients who underwent colostomy takedown were identified (no bowel preparation: 37%
oral antibiotic only: 7%
mechanical bowel preparation only: 13%
combined oral antibiotic + mechanical bowel preparation: 42%). Patients who had oral antibiotic + mechanical bowel preparation had significantly lower 30-day rates of organ/space surgical site infection, sepsis, septic shock, anastomotic leak, prolonged ileus, wound disruption, and length of stay (P <
.05). On multivariate analysis, combined oral antibiotic + mechanical bowel preparation was associated with lower adjusted odds of infectious complications (adjusted odds ratio: 0.52, P <
.05) and anastomotic leak (adjusted odds ratio: 0.37, P <
.05). CONCLUSION: This is the first study specifically demonstrating that combined oral antibiotic and mechanical bowel preparation may reduce infectious complications and anastomotic leaks without increasing Clostridium difficile colitis and acute kidney injury after adult elective colostomy reversal. Granular, large-scale, prospective studies are warranted to replicate these findings and identify opportunities for quality improvement.