[Modern mechanical antibiotic preparation in colorectal operations. Results of a prospective study].

A prospective clinical study was made to compare the effectiveness of a short-term oral antibiotic prophylaxis (neomycin) and a longacting oral-parenteral aerobically and anaerobically effective combination (neomycin, metronidazol, chloramphenicol) on the incidence of wound infections. All patients had orthograde lavage as a mechanical bowel preparation. Preoperative administration of the antibiotic combination before lavage could not reduce the relative aerobic bacterial count of the faeces. The incidence of wound infections was nearly identical with 4/89 in the neomycin group and 5/114 in the combination group. In the neomycin group there occurred 2/44 anastomotic dehiscences, but none in the combination group (0/65). Lethal complications were significantly higher in the neomycin group (7/89 to 2/114), whereas nonlethal complications were not significantly higher in the combination group. These data suggest that long-term, oral-parenteral prophylaxis with an antibiotic combination was not superior to a short-term, sole neomycin prophylaxis applied after orthograde lavage. Cleansing the bowel as completely as possible is a fundamental prerequisite for an effective antibiotic prophylaxis.