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.
Metronidazole vs. erythromycin, neomycin, and cefazolin in prophylaxis for colonic surgery.
A prospective, double-blind, randomized study was undertaken to compare perioperative parenteral metronidazole and erythromycin, One neomycin, and cefazolinhundred fifty-five patients were randomized into two groups by the pharmacy department. The resulting difference between the overall septic complication rate in patients receiving erythromycin, neomycin, and cefazolin (10.9 percent) and the rate in patients receiving metronidazole alone (31.9 percent) was significant. This indicates that an antibiotic to cover aerobic bacteria should be added to the regimen when metronidazole is used.