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.
Multicenter study of aztreonam in the prophylaxis of colorectal, gynecologic and urologic surgery.
The preliminary results of four multicenter, comparative protocols on the efficacy and safety of aztreonam are discussed. This monobactam antibiotic was used as short-term prophylaxis in patients undergoing colorectal, gynecologic or urologic surgery. When compared with gentamicin in a group of 295 patients undergoing colorectal surgery, aztreonam significantly reduced the incidence of abdominal wound infection (p less than 0.025); it also reduced the incidence of perineal wound and intra-abdominal infections, although these differences were not statistically significant. In patients undergoing abdominal and vaginal hysterectomy, aztreonam was compared with cefotaxime (both combined with clindamycin) in 170 and 142 patients, respectively. No difference in the incidence of infection was found between the two treatment regimens. In the 175 patients undergoing transurethral resection of the prostate, aztreonam was compared with placebo. The prophylactic regimen significantly reduced the number of urinary tract infections (p less than or equal to 0.0001). Its efficacy was particularly evident during the first 10 postoperative days. Side effects experienced by patients taking aztreonam were minor and similar in all three treatment groups studied. Aztreonam (alone or combined with clindamycin) offers a new and efficacious alternative to the standard antibiotic regimens currently used prophylactically in the high-risk postoperative patient.