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.
Short-term antibiotic prophylaxis in elective colorectal surgery.
In the last 2 years, 50 patients who underwent elective colorectal surgery were prospectively studied about antibiotic prophylaxis. Two groups of 25 patients each were randomly selected. Both received: (a) a colic preparation: hypactic drugs and two enemas during the day before surgery and (b) metronidazole 0.5 g plus neomycin 1 g per 8 h orally for 1 day before surgery. Every group also received: group A, metronidazole 0.5 g plus amikacin 500 mg i.v. 2 h before surgery and the same doses per 8 or 12 h, respectively, for 2 days postoperatively; group B, ornidazole 1 g by intravenous infusion plus ceftriaxone 2 g i.v. 2 h before surgery and the same doses of the drugs per 24 h for 2 days postoperatively. Wound infection occurred in 1 case of group A versus 2 cases of group B (p greater than 0.25). Ornidazole plus ceftriaxone prophylactic antibiotic therapy is therefore as effective as a classic therapy (metronidazole plus amikacin) and constitutes an alternative choice for patients undergoing elective colorectal surgery, because the simple manner of its administration (once per 24 h) is resulting in cost saving due to gained nursing time.