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.
Peroperative systemic prophylaxis in colorectal surgery.
In an effort to reduce infection rates in elective colorectal surgery to acceptable levels without oral non-absorbable antimicrobials, using only a short course of systemic antimicrobials, 50 patients were studied in a multicentre trial. Each patient received metronidazole for anti-anaerobic coverage. The anti-aerobic coverage consisted of netilmicin, cefuroxime or placebo, administered in a double-blind manner. Five out of 36 evaluable patients had an infection at the operation site. Two patients had peritonitis (one metronidazole-netilmicin and one metronidazole-placebo) and three had a wound abscess in the abdominal wall (all metronidazole-placebo). It is concluded that a short course of peroperative systemic prophylaxis with metronidazole and netilmicin or cefuroxime--without the use of oral non-absorbable antimicrobials--gave acceptable results in the centres studied.