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.
A multicenter study to compare cefotetan alone with cefotetan and metronidazole as prophylaxis against infection in elective colorectal operations.
The role of antibiotic prophylaxis in operations upon the colon and rectum is now well recognized. In this study, the efficacy of cefotetan, a broad spectrum cephamycin antibiotic, given alone (n = 315), is compared with that of the combination of cefotetan and metronidazole (n = 300). The groups were well matched for age, sex, pathologic features and operations performed. There was no statistical difference in the incidence of operation-related infection between the two groups. We conclude that cefotetan given alone is as effective as the combination of cefotetan and metronidazole for prophylaxis against operation-related infection in elective colorectal operations.