Hi Oddiggy-
I was diagnosed with Crohn's Disease and had a vaginal fistula all within 2 months. I had a seton put in then they took it out to see if the fistula would heal, it didn't so they put the seton back in then took it back out in about 3 months. They started me on Remicade, which made the fistula smaller but it still didn't heal and continued to drain. Last July I had surgery to repair the fistula. My surgery was not easy. They had to do a skin graft in addition to the fistula repair to cover the mucosal tissue they pulled down. I did not fully heal until September. I now am very happy that the surgery was successful. I don't miss the drainage at all. I notice now though when I have a Crohn's flare up that I have discomfort and itching on the scar tissue at the surgery site. When they first advised me that I needed to have surgery I refused and put it off for about a year. You have to be ready to do it.
Hope all goes well for you-