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.
[Antimicrobial chemoprevention in colorectal interventions: a single parenteral dose at the start of surgery is adequate].
The effectivity in reducing septic complications after colorectal operations of oral 1 g Neomycin plus 0.25 g Metronidazol t.i.d. on the last preoperative day vs. intravenous single dose 5 g Mezlocillin plus 0.5 g Metronidazole was tested by sequential medical plan. There was no statistically significant difference between both chemoprophylaxis groups (p = 0.10). It is concluded that the intravenous chemoprophylaxis should be preferred because of the lowest dosage and therefore the fewest side-effects.