I was prescribed metronidazole. i use feminine wash (outside, never inside vagina) but i read that you shouldn't use it while taking this.is that tru?

Probably a good idea: Metronidazole oral tablets are most typically prescribed for a trichomonas vaginal infection. While there are no specific instructions about avoiding "external washing" while taking this, one would want to avoid anything that could alter the vaginal pH in order to optimize the expected effect of these antibiotics. It probably is a good idea to avoid your external wash. Good wishes:)