Here are a few things that you can try. Eliminate all refined sugar from your diet. One of the worst things you can do is to eat anything with artificial coloring in it. Especially Yellow #5 and red #40 or carmel coloring. They are all irritants. I have had this rpoblem for 24 years. I am only bothered buy it if I have one of these items. Ginger is also added to the list. I find that this does not cause problems unless I have too much. Do you drink unsweeted cranberry juice. The junk that you get in the market from any of the big companies has mostly sugar and not enough cranberry. That can be found at most health food stores. I hear people all the time say that the coloring is only such a small amount that they don't see how it can hurt them. If you are sensitive to it it can kill you. I now have severve allergies to most food coloring. The cystitis was just my body's way of telling me.