Systemic prophylaxis with doxycycline in intestinal surgery on patients with high incidence of abnormal fecal flora.

Resistance of the fecal bacterial flora to doxycycline was studied before, during and after systemic prophylaxis with that agent in 24 patients undergoing surgery for complex intestinal disorders, 14 of whom had received antibiotics during the preceding 6 months. Fecal specimens for bacteriologic culture were obtained preoperatively, at operation and 3 days, 1 week and 4 weeks postoperatively. In nine patients (38%) there was dominance of doxycycline-resistant strains preoperatively. At 3 days and 1 week postoperatively the corresponding figures were around 55%. Dominance of doxycycline-resistant bacteria was found in altogether 20 patients at some time during the 4 postoperative weeks. At 4 weeks the fecal flora was normal in 22 of the 24 patients. Antibiotics other than doxycycline should be preferred for prophylaxis in patients undergoing complex, revisional or repeat bowel surgery, especially if they have received antibiotic treatment in the preceding 3-6 months.