I ask, because if you had a fistula that let gas come through into the vagina from the colon or lower intestine, it would let
solids and liquids come through as well. Besides, your doctor would have seen or felt it. Did your doctor swab you for BV last time? It could be a combo of trapped air in the vagina making its way out (i.e., a queef) given an odor from BV or remnant of a forgotten tampon, or something like that.