BackgroundColorectal surgery still experiences high rates of infectious complications, such as anastomotic leakage and surgical site infections. Therefore, oral antibiotic bowel decontamination has experienced a renaissance. But data on perioperative selective digestive tract decontamination (SDD) based regimens or combined bowel preparation are inconsistent. Nonetheless, with widespread use of enhanced-recovery after surgery concepts, the ideal length for perioperative SDD treatment has to be reconsidered. MethodsPerioperative outcome was analysed in a cohort of patients undergoing minimally invasive surgery for left sided colorectal cancer in a retrospective study. Additional to usual perioperative outcome measures anastomotic leakage, surgical site infections and overall infectious complications, the efficacy of a shortened 3 postoperative day perioperative oral antibiotic bowel decontamination treatment was compared to a 7 postoperative days regimen based on a non-inferiority analysis. ResultsOverall, n=256 patients were included into analysis, of whom n=84 patients were treated by a 3 days and n=172 patients by a 7 days perioperative oral antibiotic bowel decontamination regimen. Anastomotic leakage occurred in 1.2% in the 3 days and 5.2% in 7 days groups and surgical site infections in 3.6% respectively 5.8% without significant difference. The shortened 3 days perioperative SDD based regimen was non-inferior to the regular 7 days SDD based regimen with regard to rates of anastomotic leakage, surgical site infections and infectious complications. ConclusionFor the first time, these data demonstrate non-inferiority of a shortened 3 days perioperative SDD based treatment compared to a 7 days regimen for anastomotic leakage, surgical site infections and overall infectious complications.