NCT04931173.

Study name	Mechanical Bowel Prep Randomized Study
Methods	Study type: interventional Study design Allocation: randomised Intervention model: this is a multi‐centre, parallel, two‐arm, non‐inferiority randomised controlled trial comparing IVA+OA+MBP versus IVA+OA to reduce surgical site infection following colon surgery Masking: none (Open Label) Primary purpose: other
Participants	Condition or disease: Colorectal surgery Inclusion criteria Undergoing elective colon surgery for benign or malignant disease Over the age of 18 years Provides informed consent Exclusion criteria Known anaphylaxis to neomycin or metronidazole Pregnancy or lactation Chronic renal failure (serum creatinine > 220 umol/L). Target sample size: 1062
Interventions	Treatment arms Group A: IV and Oral antibiotics (IVA+OA)Patients will receive cefazolin 2g IV and metronidazole 500 mg IV administered by the anaesthesiologist within 60 minutes prior to the skin incision on the day of surgery. Standardised re‐dosing of cefazolin 2g IV will occur every 4 hours and metronidazole 500 mg IV will occur every 8 hours during the surgical procedure. Following surgery, no further IVA will be given for SSI prophylaxis. In addition, patients will self‐administer 1g neomycin and 1g metronidazole orally at 1500, 1700 and 2300 hours the day before surgery. Following this, they will not receive any further OAs for SSI prophylaxis. Group B: IV antibiotics, MBP and oral antibiotics (IVA+MBP+OA) Patients will receive IVA and OA per Group A. In addition, patients will stay on clear fluids and self‐administer a 2L polyethylene glycol MBP orally, between 1500 and 2300 hours on the day before surgery.
Outcomes	Primary outcome Surgical Site Infection Rate [Time Frame: 30 days following date of surgery] Secondary outcomes Patient tolerability of the bowel preparation [Time Frame: 5 minutes (completed in pre‐operative holding area on the day of surgery)] Length of stay [Time Frame: 2‐7 days] 30‐day ER rate [Time Frame: 30 days] 30‐day readmission rate [Time Frame: 30 days]
Starting date	Date of registration: June 18, 2021 EstimatedStudy Start Date: April 2022 Estimated Primary Completion Date: December 2025 Recruitment Status: not yet recruiting
Contact information	Contact person: Erin Kennedy Affiliation: Division of General Surgery, Mount Sinai Hospital, Canada Country of origin: Canada
Notes	Ethics approval: ‐ Source of funding: ‐