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.
Comparison of systemic prophylaxis with metronidazole/placebo and metronidazole/fosfomycin in colorectal surgery. A clinical study demonstrating the need for additional anti-aerobic prophylactic cover.
The aim of this randomized double-blind study comparing the efficacy of two prophylactic regimens, metronidazole/placebo (n = 23) and metronidazole/fosfomycin (n = 26) was two-fold. First, to evaluate the need for anti-aerobic cover in addition to short-term systemic administration of metronidazole against anaerobes in colorectal surgery. Secondly, to explore the prophylactic effect of fosfomycin on aerobes of intestinal origin. An unacceptably high rate of surgical sepsis (16.3%) forced premature conclusion of the study after 49 patients had entered it. All surgical and remote infections occurred in the metronidazole/placebo group and were caused solely by aerobes. Anaerobic sepsis was not seen at all and the surgical infection rate was 34.8%. No septic complications occurred in the 26 patients (0%) receiving metronidazole/fosfomycin (p less than 0.01). Thus the study demonstrated both the need to administer an effective anti-aerobic agent in addition to metronidazole in colorectal surgery and the efficacy of fosfomycin in preventing aerobic sepsis of intestinal origin. Adverse reactions to the two drugs were not observed and resistance did not occur.