I had that surgery 3 weeks ago this Saturday. It was done laproscopicly. Mine was so bad ( an abcess formed in the fistula ) they had to remove 10 " of colon.
I was lucky that the bladder had healed, and didn't need any work. On the other hand, I did have to have a bag, so I will have to go through it again in a few months to reconnect the original plumbing.
The surgery does have quite a lot of pain with it, but with the meds they have now in iv form, it is tolerable. I would say to you, have the surgery done before it gets out of hand like mine did. It was 10 days before I got out of the hospital. It is also not much fun peeing poop. And talk about
One last thought, the ostomy bag is something I had feared all my life. With the new new bags they have, it is a breeze, and cleanup is simple.
I can now sleep all through the night without having to empty the bag. I have only had 3 accidents, and they were all in the middle of the night.
These were all caused by trying to use the 2 piece bags on a round belly. With the one piece, no problem.
Hope this helps, and best of luck.