Mechanical bowel preparation combined with oral antibiotics in colorectal cancer surgery: a nationwide population-based study.

The guidelines for reducing surgical site infection in colorectal surgery recommend mechanical bowel preparation with oral antibiotics; however, this recommendation remains controversial. This study aimed to reveal the effect of oral antibiotics combined with mechanical bowel preparation in colorectal surgery. This study was a nationwide population-based retrospective study. Data between January 1, 2016, and December 31, 2018, from the Korean National Health Insurance Service database were analyzed. Patients who underwent elective colorectal cancer surgery were included. A total of 20,740 patients were finally included, comprising 14,554 (70.2%) who underwent mechanical bowel preparation alone and 6186 (29.8%) who underwent mechanical bowel preparation with oral antibiotics. The mechanical bowel preparation alone group was older than the mechanical bowel preparation with oral antibiotics group (65.7 ± 11.9 vs. 64.7 ± 11.8 years, p < 0.001). Rectal cancer patients and patients who underwent open surgery were more likely to receive mechanical bowel preparation with oral antibiotics. Patients who underwent mechanical bowel preparation with oral antibiotics demonstrated lower surgical-site infection rate (2.9% vs. 9.4%, p < 0.001), shorter hospital stay (11.7 ± 5.5 vs. 13.5 ± 7.3 days, p < 0.001), and lower medical cost (US$7414 ± 2762 vs. US$7791 ± 3235, p < 0.001) than those who underwent mechanical bowel preparation alone. The 30-day readmission rates and mortality were not significantly different. The use of mechanical bowel preparation with oral antibiotics reduces surgical site infection, hospital stay, and medical cost in colorectal cancer surgery.