I have been recently diagnosed with interstitial cystitis. I haven't been able to link it to my diet, although green tea seems to irritate it a bit.
I found a supplement called serrapeptase and have been taking it for a couple weeks. It seems to help the inflammation of this and also arthritis pain and migraine headaches.
A google search will lead you to research and sources to purchase it. I highly recommend checking it out, especially if you don't like to take pharmaceuticals for inflammatory conditions.