I had metronidazole flagyl 2grams last 2days ago. but i still have this vaginal discharge. when will i see the effect?

Trichomonas Rx: If the Flagyl was for trichomonas, then the dose may need to be repeated or given for a longer period of time if it was a 2 gram dose taken all at once. Your sexual partner should also have been treated before sexual activity was resumed. Your MD should re-check the discharge to see if it has been cleared or not to determine the next step.

Trichomonas: 2 gms of Flagyl is typically given for trichomonas as single dose and it should work promptly. If after 48 hours there is no effect, I doubt the diagnosis of trichomonas without something else like bacterial vaginosis, and if it still is trichomonas an extended course of Flagyl, e.g., 7 days, may yield results.