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.
Peri-operative infection prophylaxis with ornidazole and gentamicin in elective colonic surgery.
In a study of 60 patients undergoing elective colonic surgery peri-operative infection prophylaxis by the "one-shot' method was compared with that of 48-hour duration. The antibacterial agents used were ornidazole and gentamicin. Considering the patient population as a whole, no significant differences were found in the results. All the infectious complications which occurred post-operatively were due to bacterial contamination by aerobic pathogens. No anaerobic pathogens were detected in any of the cases.