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.
Amoxycillin/clavulanic acid prophylaxis in elective colorectal surgery: a prospective randomized trial.
In a randomized trial of 440 patients undergoing elective colorectal surgery, the prophylactic efficacy and the safety of amoxycillin/clavulanic acid were compared with that of a control regimen of clindamycin and gentamicin. Surgical wound healing was assessed by the ASEPSIS points scale; it was normal in 86% of patients and the scores for both groups were not statistically different (amoxycillin/clavulanic acid: 11.1; clindamycin + gentamicin: 10.9). Intra-abdominal infections were more frequent in the clindamycin + gentamicin arm of the study (Fisher's exact test, P = 0.035). It is concluded that amoxycillin/clavulanic acid is as effective and safe as clindamycin + gentamicin in the prevention of wound infection and may provide better protection against intra-abdominal infections.