If i had a fistula would the poop only come out vagina when you poop or all the time?

All the time: Since the anal sphincter is below the vagina, feces would extrude into the vagina at all times without attempting to defecate.

Here are some....: If having rectovaginal fistula, the degree and amount of poop out of vagina could widely vary reflecting the size of fistula, the features of poop - formed or watery or in between, and the function of anus. So, one affected with rectovaginal fistula may not see poop out of vagina at all if the fistula is tiny like a pinhole, poop is formed, and anus relaxes well; vice versa. All the best to health