A prospective, randomized, controlled clinical trial compared metronidazole 250 mg orally four times daily ... failures occurred with vancomycin use, but the difference was not significant.

Metronidazole (Flagyl) 500 mg orally twice a day for 7 days Metronidazole (Flagyl) 250 mg orally three times a day for 7 days Clindamycin 300 mg orally twice a day for 7 days Metronidazole (Flagyl ...