A 34-year-old woman presents with copious vaginal discharge with foul odour. Discharge is gray in color, microscopic examination reveals clue cells. The treatment of choice is:-

BACTERIAL VAGINOSIS A fishy vaginal odor, which is paicularly noticeable following coitus. Vaginal secretions are gray and thinly coat the vaginal walls. The pH of these secretions is higher than 4.5 (usually 4.7 to 5.7). Microscopy of the vaginal secretions reveals an increased number of clue cells, and leukocytes are conspicuously absent. Severe BV, more than 20% of the epithelial cells are clue cells The addition of KOH to the vaginal secretions (the "whiff" test) releases a fishy, amine like odor. Metronidazole is drug of choice: