Parenteral Antibiotics Compared to Combination of Oral and Parenteral Antibiotics in Colorectal Surgery Prophylaxis

Routine antibiotics for the intravenous and oral prophylaxis of colorectal surgery will be used. Experimental group: Patients undergoing elective colorectal surgery that involves, colonic resection. The antibiotic prophylaxis in this group will be composed of: An oral antibiotic pattern of ciprofloxacin (750mg / 12h, 2 doses) and metronidazole (250mg / 8h, 3 doses) the day before surgery. + Control group: Patients undergoing elective colorectal surgery that involves, colonic resection. The antibiotic prophylaxis in this group will be composed of: An intravenous antibiotic pattern of cefuroxime 1g and metronidazole 1,5gr during anesthetic induction. In both groups a second intravenous dose of cefuroxime (750mg) will be administered if the intraoperative time elongates more than three hours or there is an intraoperative bleeding over 1000cc. There won´t be a placebo treatment. Subject compliance will be evaluated according to the usual practice in surgical care field