For a long time I thought it was my bladder that hurt... turned out a fistula in the rectal region. not saying that's what your situation is, but it is something that came to my mind. The rectum and the bladder are quite close and it's tough to tell the difference. However, I never had any UTI symptoms - burning during urination, blood in urine, or even frequency. It just hurt like heck every time I sat on the toilet - for either reason. I also ran a fever, low-grade over severals weeks/months.
Just one idea, talk to your doc and get the tests done... Hope you feel better soon!
--40 year old female, dx as UC in '04 (1st symptoms in '03), switched to Crohn's in '05, 1 fistula, crohn's colitis, limited to large intestine
--rejected (reaction/didn't work): Asacol, AZA, 6-MP, MTX, Remicade, Humira, prednisone
--methylpred - finally off 6/15/08, tried Prochymal in Phase III study (can't wait til it's approved!)
--started Tysabri 3/21/08
--single mom to 10-yr-old girl