I know how frustrating it is to run to the dr. over and over with burning and they don't find any infection..been there, done that! I have a disorder called interstitial cystitis which is basically an inflammation of the bladder and urinary tract. I don't think you have enough symptoms for that diagnosis, you have to have bladder pain, but you do have SOME of them and might be having some of the same issues. They don't know what causes it, maybe an autoimmune disorder or something in our processed food, no one knows.

I have bladder pain and burning, can be together or separate. Getting relief from drinking a lot of water and having irritation from certain foods are typical symptoms of this. I have problems if I overdo anything with too much caffeine but spicey things bother me too. Orange juice etc. are also offenders, I can't drink much oj unless I get the kind with calcium which seems to buffer the acid a little.

There really aren't any very good treatments for this. I respond to antibiotics because I tend to get lesions and blister-like eruptions but as soon as I'm off the drugs it all comes back anyway. What has actually helped me the most is I got one of those 'Pur' water filters you put on your faucet because my sister was complaining about chlorine taste in her coffee. It doesn't seem to make any sense, but even though I got relief from drinking cholorinated water it must have been irritating too, The filter really worked better than anything dr. has done. I don't drink nearly as much water and can eat more chocolate, etc.

There is also something called neurogenic bladder that they treat with antidepressants. It doesn't mean its all in your head, just that the pain comes from problems with the nerves instead of disease. I think that can cause burning too.

You can find info online about both of these. Try to be aware of anything you eat that sounds like it would irritate inflamed tissues and if you can afford it try a faucet filter, if nothing else your coffee will taste better. I assume they checked for a yeast infection, those will really make you burn. I was also wondering if you'd changed laundry soap, some of them can be irritating if you use too much. Have you asked an ob/gyn about irritation?

I hope I've given you some ideas on where to look for relief, there may not be a simple fix. You really are drinking a lot of water and I hope you can find some solutions.

Zygo