Interstitial Cystitis? or something else?

ive been to so many urologist and gyno doctors and they never figured out what was wrong with me. they said i had overactive bladder to and put me on pills for it which didnt help and i was experiencing the side effects. the urologist wanted to do a camera test to see if anything was wrong its were they stick a little scope camera up the uretha i think but i didnt want to do that becuase of the pain and the money mostly the pain so you could ask for that if you want but its sounds to painful. what i started doing was taking cranberry pills everyday and drinking tons of water staying away from soda. it helps a bit.