Antibiotics covering aerobic and aerobic bacteria should be delivered orally and intravenously prior to colorectal surgery.  Antibiotics delivered within this framework will reduce the risk of postoperative SWI by at least 75%.  Further research is required to establish the optimal timing and duration of dosing, and frequency of longer-term adverse effects such as Clostridium difficile pseudomembranous colitis.
Prophylactic antibiotics in elective colon surgery.
A double-blind, randomized, prospective study comparing the efficacy of two intravenously administered antibiotics was conducted at Vancouver General Hospital on 98 patients undergoing elective colon surgery. The test drugs, erythromycin gluceptate and metronidazole, were each administered intravenously in 500 mg doses. The first dose was administered with the premedication 1 hour before surgery and the subsequent two doses were administered at 8-hour intervals. All patients received three doses of tobramycin intravenously, 1.5 mg/kg body weight, at the same time as the study drug. Fourteen patients developed wound infections, of which seven were classified as major and seven as minor infections. A major infection was diagnosed when the patient had a fever, required antibiotics, or had a prolonged hospital stay because of the wound infection. Three patients with major infections had received metronidazole and four had received erythromycin. Four patients with minor infections had received metronidazole and three patients had received erythromycin. The two treatment populations were similar with respect to type of surgery, age, gender, weight, and nutritional status. Both drugs were equally well tolerated. The overall wound infection was 14.4%, with no difference between erythromycin and metronidazole.