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.
Is neomycin necessary for bowel preparation in surgery of the colon? Oral neomycin plus erythromycin versus erythromycin-metronidazole.
In 132 patients who underwent elective surgery of the colon, the value of bowel preparation with a conventional oral antibiotic preparation of neomycin-erythromycin (N-E) was compared with erythromycin-metronidazole (E-M). Of 125 patients who were available for assessment, 61 received N-E and 64 E-M. The two groups were evenly matched. Two wound infections occurred in patients receiving E-M, neither due to anaerobic bacteria, but seven wound infections developed in patients given N-E (p = 0.057), five of them caused by anaerobic bacteria. Anaerobic bacteria of the colon are the dominant cause of postoperative wound infection in elective surgery of the colon. Adequate antibiotic preparation directed against these bacteria makes the use of neomycin unnecessary.