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.
[Antibiotic prophylaxis in colon surgery: cefazolin (Kefzol- ornidazole (Tiberal) versus cephazolin-placebo].
A prospective, randomized, double-blind and controlled clinical trial of systemic antibiotic prophylaxis with Cefazolin and Ornidazol (CO) versus Cefazolin and Placebo (CP) was carried out consecutively in 100 patients undergoing elective, colorectal surgery. The incidence of wound infection in the CP-group was 20% (n = 10) and in the CO-group 8% (n = 4) (p less than 0.10 ns). The reduction of anaerobic bacterias from 20% (n = 10) in the CP-group to 0% (n = 0) (CO) was significant (a1 = 0.0139; a2 = 0.0277 s, Fischer's exact test). The time of hospitalization was reduced from 20.3 days (CP) to 16.7 days (CO) (p less than 0.05 s). The agent for antibiotic prophylaxis in elective colorectal surgery is to cover the spectrum of anaerobic bacterias.