infectious surgical site complications after oral antibiotic bowel preparation for minimally-invasive rectal cancer surgery

Interventions: Drug : 1. experimental group (A)
- mechanical bowel preparation (PEG) + IV antibiotics
2. control group (B)
- mechanical bowel preparation (PEG) + IV antibiotics + oral antibiotics (rifaximin + metronidazole)
3. pre-operative preparation
3.1. mechanical bowel preparation
- PEG prefered
- water only permitted on the day before operation
3.2. oral antibiotics
- 14, 16, 22 hour the day before surgery
- 400mg rifaximin + 500mg metronidazole
3.3. IV antibiotics
- 2nd generation cephalosporin
- venous injection within 30 minutes before surgery
- additional dose is at the discretion of the operators
Primary outcome(s): surgical site infection rate during first 30 days
Primary Purpose : Prevention, Intervention Model : Factorial, Blinding/Masking : Open, Allocation : RCT