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.
Selective decontamination of the colon before elective colorectal surgery. West of Scotland Surgical Infection Study Group.
The controversy over the route of administration of antibiotic prophylaxis in patients undergoing elective colorectal operations persists for oral, parenteral, and a combination of the two routes. The oral antibiotics commonly administered for colorectal prophylaxis, neomycin and eythromycin base, are not absorbed in the gastrointestinal tract (GIT). However, the 4-fluoroquinolones are absorbed in the upper GIT and are excreted in part by the colonic mucosa. Their action is then to remove, or severely depress, the gram-negative aerobic bacilli leaving the anaerobic flora unaffected. This action is the principle of selective decontamination. We have assessed the efficacy of oral ciprofloxacin in a prospective randomized clinical trial in which all patients received piperacillin 4 g i.v. as single-dose parenteral prophylaxis. A group of 327 evaluable patients were randomized to receive ciprofloxacin 500 mg b.i.d. with the preoperative cathartic (group OA, n = 159) or no oral antibiotic (group NOA, n = 168). Postoperative wound infection occurred in 18 (11.3%) patients in group OA and 39 (23.2%) patients in group NOA (chi 2 = 7.2, p = 0.007). Operation-related infection of any type occurred in 23 (14.5%) patients in group OA compared with 55 (32.7%) in group NOA (chi 2 = 14.0, p = 0.0002). The median postoperative hospital stay was 11 days (interquartile range 4.5 days) for group OA and 12 days (interquartile range 8 days) for group NOA (Mann Whitney U test, p = 0.005). Ignoring the treatment group, the median postoperative hospital stay was 17 days (interquartile range 10 days) for infected patients and 11 days (interquartile range 4 days) for those not infected.(ABSTRACT TRUNCATED AT 250 WORDS)