You need a good colon & rectal surgeon. Having the best surgeon doesn't mean you will have success however. I am on my 3rd right now because the second made it way worse. Really wish i wouldn't have messed with it after the first surgery. The first wasn't successful buy it was just a pin hole from the rectum to the vagina. Dealt with it for 16 years and thought I would try to have it repaired again. There was sphincter muscle damage and since the first one didn't work, which was just an advancement flap, that having the more invasive sphinctoplasy surgery would give me a greater chance of success. WRONG!! The would opened (they go in through the perineum rather than the rectum) and the wound opened. Now much worse as I had gas coming through my ass, vagina and now the perineum opening. Talk about suck. Third surgery now (12 days post-op) and no luck. I've seen two stitches for sure and gas and BM is coming through the perineal and vagina.
Wish you luck but if you only have gas coming through your vagina. Let well enough alone.