Effect of oral antibiotic bowel preparation on colorectal surgical site infection rates

Patients who undergo colorectal surgery are at a 25% increased risk of developing a surgical site infection (SSI) compared to other surgery types, with 55% of these infections categorized as preventable. Oral antibiotic bowel preparation (OABP), consisting of neomycin plus metronidazole and/or erythromycin, has been demonstrated to reduce the rate of SSIs from colorectal surgery by up to 67%. This was a single-center, retrospective study conducted at an academic hospital for the time period from January to October 2023. All adult patients who underwent colorectal surgery were included except those who were pregnant or had emergent surgery. Use of OABP resulted in a significantly lower rate of colorectal SSIs (0% in the OABP group vs 6.6% in the no-OABP group; P = 0.0425). We found that outpatients were more likely to receive OABP than inpatients (89% vs 62%; P = 0.0003), and more patients received concomitant mechanical bowel preparation in the OABP group (85%) than in the no-OABP group (65%), with a P value of 0.0053. Additionally, those without OABP had a longer length of stay (5.4 days with OABP vs 8.9 days without OABP; P = 0.0008). There appears to be an association between use of OABP and SSI rate in patients undergoing colorectal surgery. This study, in agreement with available literature, supports the standardization of OABP utilization. Larger studies are warranted to explore the financial implications of utilizing OABP.