It is approved on a case by case basis. You will need to submit the medical records from the urologist to the FAA in OKC and ask for a review of the file and a Special Issuance medical certificate. If you need help go to
http://www.faaspecialissuance.com
Interstitial cystitis is a very painful and debilitating disease. There is no known cause and the treatment works sometimes. If Elmiron works, be thankful. I have treeated several cases over the years and it is like the heartbreak of psoriasis.