Intravenous Versus Combined Oral and Intravenous Antimicrobial Prophylaxis for the Prevention of Surgical Site Infection in Elective Colorectal Surgery

Inclusion Criteria: * Age \> 18 * Laparoscopic or non-laparoscopic elective colorectal surgery Exclusion Criteria: * Non elective colorectal surgery (emergent surgery and/or reintervention or revision of a previous colorectal procedure) * Significant concomitant surgical procedure (e.g., liver resection for metastasis) * Bacterial infection at the time of surgery or antimicrobial therapy up to 2 weeks before surgery * Inflammatory bowel disease * Severe obesity (defined as a BMI \>35 kg/m2) * Known history of hypersensitivity to β-lactams and imidazoles * Preoperative severe impairment in renal function (creatinine clearance (MDRD) \< 30 ml/min) * Patients with known colonization with multidrug-resistant digestive bacteria, especially multidrug-resistant gram-negative bacteria (requiring specific infection control measures) * Allergy to lactose, galactose intolerance, Lapp lactase deficiency or glucose/galactose malabsorption (rare metabolic disease) * Pregnant women, breastfeeding women, women of childbearing age without effective contraceptive- Refusal to participate or inability to provide informed consent