Interstitial cystitis (in-tur-STISH-ul sis-TIE-tis) is a chronic condition causing bladder pressure, bladder pain and sometimes pelvic pain. The pain ranges from mild discomfort to severe pain. The condition is a part of a spectrum of diseases known as painful bladder syndrome. Your bladder is a hollow, muscular organ that stores urine. The bladder expands until it's full and then signals your brain that it's time to urinate, communicating through...