I had several surgeries-glue, plug, seton, visceral sealing. I had UC and a jpouch at the time and my GI was more than willing to try any biologic as long as I was okay with it. I then became a patient of Dr. Shen at the Clinic because my GI was out of options and it wasn't healing. Dr. Shen did these injections in my pouch to help seal it up but that would require several visits that I could not do to Cleveland. I remember Dr. Shen not promoting biologics at all. Because the fistula was cumbersome (stool passing through my vagina), I had surgery for a 'temporary' ostomy in my home town and continued using biologics to try and heal. It never did heal; I decided to have my jpouch removed (it was failing and I would never be hooked up again) and knew the temporary ostomy became permanent. I went on to have a mucosectomy where a urogynecologist fixed the fistula by - simply put - using excess skin connect and 'cover'. This surgery 'cured' my fistula and all drainage associated with it, from vagina and rectum. But for me I had a permanent ostomy that I did not like.
I now have a K-pouch since I didn't live well with an ostomy. But I am sorry you are dealing with a fistula...there are no easy fixes and they are cumbersome and painful too.