Prevention of wound infections after colorectal surgery using antibiotics prior to surgery

INTERVENTION: Intervention The intervention is a preoperative oral antibiotic prophylaxis (Pre‐OP), which is a solution of colistin sulphate and tobramycin. Pre‐OP is administered 4 times daily (5 mL per dose) during the last 3 days prior to surgery. Control group The control group receives a placebo without the active antimicrobial ingredients but with a similar taste and color. All patients receive perioperative intravenous antibiotic prophylaxis in accordance with the national infection control guidelines. CONDITION: Postoperative inflammation, Colorectal surgery ; ; PRIMARY OUTCOME: The cumulative incidence of deep surgical site infections and/or mortality within 30 days after elective colorectal surgery SECONDARY OUTCOME: 1. Deep surgical site infections ; ; 2. 30‐day mortality ; ; 3. Superficial surgical site infections ; ; 4. Anastomotic leakage ; ; 5. Relaparotomy ; ; 6. Bacteremia ; ; 7. Infections with highly resistant Enterobacteriaceae (HRE) or Clostridium difficile ; ; 8. Presence of HRE in intestinal flora ; ; 9. In‐hospital use of antibiotics ; ; 10. 6‐month mortality ; ; 11. Postoperative length of hospital stay ; ; 12. Postoperative length of ICU stay ; ; 13. Quality of life ; ; 14. In‐hospital costs ; INCLUSION CRITERIA: • Patients aged 18 years or older • Patients undergoing elective colorectal surgery • Patients may not meet any of the exclusion criteria