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The reasons for having brown vaginal discharge could be many. Each of these following causes have additional symptoms associated along with having brown discharge as one of the symptoms. These are: PID (pelvic inflammatory disease), Genital warts, Gonorrhoea, Chlamydia, Vulvovaginitis, cervical cancer, menopause, vaginal bleeding in between periods.
If you are having brown vaginal discharge, then discuss about these with your gynecologist and get examination and tests done to see which one the underlying cause in your case.
Take care.