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.
Effectiveness of single dose prophylaxis with cefotaxime and metronidazole compared with three doses of cefotaxime alone in elective colorectal surgery.
To compare three doses of cefotaxime alone with a single dose of cefotaxime and metronidazole for the prophylaxis of infection after elective colorectal operations.
                Prospective random control trial.
                Hillerød and Frederiksberg Hospitals, Copenhagen, Denmark.
                660 consecutive patients who were to undergo elective colorectal operations during a 48 month period (January 1987-January 1991); 93 (14%) were withdrawn after randomisation leaving 567 for assessment.
                Mechanical bowel preparation, and then either cefotaxime (Claforan) 2 g intravenously at induction of anaestesia and 3 and 9 hours later (n = 280) or a single dose of cefotaxime 2 g plus metronidazole (Flagyl) 1.5 g intravenously at induction of anaestesia (n = 287).
                44 patients in the cefotaxime group developed wound infection (16%) compared with 19 (7%) in the combined group (p < 0.001). In the cefotaxime group 22 of the 241 patients who had an anastomosis developed leaks (9%) compared with 8 of the 239 in the cefotaxime/metronidazole group (3%). There were no differences in the incidence of intra-abdominal abscesses or burst abdomens. The most common organisms isolated from wounds were Escherichia coli and Bacteriodes fragilis.
                One dose of cefotaxime and metronidazole is active against a wide range of organisms and resulted in significantly fewer wound infections than three doses of cefotaxime alone.