[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.