Cefdinir-Ornidazole for Bowel Preparation Before Colorectal Surgery: A Retrospective Cohort Study.

Mechanical bowel preparation (MBP) combined with oral antibiotics (OAB) before colorectal surgery was significantly associated with reduced surgical site infection (SSI) rates. However, aminoglycoside oral preparations are not available in Chinese medical institutions; it is necessary to find an alternative. This study aimed to investigate whether MBP combined with oral cefdinir and ornidazole was associated with lower SSI rates. This retrospective cohort study included patients who underwent elective colorectal surgery between June 2019 and May 2021. Patients were stratified into two groups based on their preoperative bowel preparation regimen: MBP alone versus MBP combined with OAB (MBP+OAB). Propensity score matching and inverse probability of treatment weighting were employed to control for confounding variables. The primary outcome was the SSI rates within 30 d postoperatively. A total of 286 patients were included, of whom 180 received MBP combined with OAB. After propensity score matching (78 patients per group), the MBP+OAB group demonstrated significantly lower rates of SSI (1.3% versus 12.8%, P = 0.016) and incisional infection (0% versus 9.0%, P = 0.023). Inverse probability of treatment weighting analysis also confirmed a reduced risk of SSI (odds ratio = 0.37, 95% confidence interval: 0.14-0.99, P = 0.048) and incisional infection (odds ratio = 0.13, 95% confidence interval: 0.03-0.55, P = 0.007). No significant differences were observed in other complications or the postoperative length of hospital stay. MBP combined with oral cefdinir and ornidazole before colorectal surgery is associated with significantly lower SSI rates. However, it remains imperative that large-scale prospective studies be conducted to validate its safety profile.