Interstitial Cystitis (IC) is a debilitating bladder disorder characterized by urinary urgency, frequency, and pain. The presentation of symptoms can be quite variable among patients, suggesting that IC is a multi-factorial syndrome with several proposed etiologies, some of which may be interrelated.1 Painful Bladder Syndrome (PBS), as defined by the International Continence Society, is "the complaint of suprapubic pain related to bladder filling, accompanied by other symptoms, such as increased daytime and night-time frequency, in the absence of proven urinary infection or other obvious pathology. 2" PBS is a clinical description of disease based on the patient's symptoms and does not depend on urodynamic or cystoscopic findings. These symptoms may be related to interstitial cystitis, although diagnostic criteria are still lacking for this entity, and the relationship between PBS and interstitial cystitis is not clear. For clarity and compliance with current nomenclature, this protocol will use the term IC/PBS.