Combined tinidazole and doxycycline prophylaxis in colorectal surgery. An interhospital trial.

There were no significant differences between randomized groups on either preoperative tinidazole or placebo added to pre-, per, and postoperative doxycycline. Cases of anaerobic infection among the placebos patients as well as a general trend of the parameters studied suggest that tinidazole gives added protection, i.e. that antibiotic prophylaxis should also comprise anaerobic microbes.