I've been having weird probs with my bladder, too! Tested for UTI, nothing there! Like once a week, I get this horrible pressure and I have to pee immediately, then it starts to burn like crazy, from the bladder all the way through the urethra. The only thing that helps is sitting on the toilet and waiting for the percocet to kick in, and then it goes away. Always happens once a week now. The only condition that matches my symptoms is interstitial cystitis. Check it out, if you figure out what's wrong with your bladder, pass on the info-maybe it'll help!