Have you been able to determine it's not a leak? Do you still have the discharge in the vagina? (as per your other post) I had a fever and just felt unwell with an undetected leak shortly after surgery that resulted in the fistula. Although I also developed pouchitis early on so it's hard to sort it out. (I still maintain the pouchitis was due to the clean out of the bowel followed by a diet of sugar (fruit juice and jello) and no probiotic...a recipe for bad bacterial production) . I also developed an 'autoimmune rash' all over my legs.
I'm hope you find a quick resolution and some peace.