Bacteroides fragilis pelvic abscess: resolution with metronidazole therapy alone.

An 81-year-old woman had Bacteroides fragilis sepsis with a sonographically demonstrated, multiply echogenic collection in the pelvis. She failed to respond to clindamycin therapy. The patient and her family refused surgical intervention. On intravenous metronidazole alone, the patient's fever decreased, she improved, and the pelvic collection disappeared in a period of between six and 30 weeks.