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.
Imipenem prophylaxis in elective colorectal surgery.
In a randomized controlled study of 411 patients undergoing elective colorectal surgery, the efficacy and safety of two different regimens of imipenem were compared with those of a control regimen of cefuroxime plus metronidazole. Surgical infections occurred in 92 (26.4 per cent) of 349 evaluable patients. There were no major differences between the three treatment groups. It is concluded that imipenem is as effective as cefuroxime plus metronidazole in the prevention of sepsis after elective colorectal procedures.