I had my illeostomy on 5/5/06 and the reversal on 7/14/06. I never really had butt burn, at least not to the extent that some people on this site have had it. In fact, I have more constipation than diarrhea.
As for the incision with my reversal, mine was stitched closed. The surgeon closed it through the ostomy site and I did not have to have the large original incision re-opened. He told me before the surgery that he would not know if he could do it through the ostomy until he got in there. If there had been excessive scar tissue or if he had other problems, he might have had to open the larger incision.
I was readmitted to the hospital several days after discharge ( from the reversal) because of pevic abscesses. I had been doing great but ended up with severe pain and a high fever. After several tests, they determine I had the two abscesses. I had a drain inserted and spent another 11 days in the hospital. I've recently been back to the ER because of abdominal pain. It feels like spasms and it's very painful. They did a CT scan but said it looks normal. I see the surgeon later this week in hopes of finding out why I'm having this pain. It just comes occasionally. Barring some major complication related to this recent pain, I am completely happy that I had the reversal. Best of luck to you and I hope this helps. I remember wanting every bit of information I could find before my reversal.