Definition Change and Update of Clinical Guidelines for Interstitial Cystitis and Bladder Pain Syndrome

The clinical guidelines for interstitial cystitis (IC) and bladder pain syndrome (BPS) have been revised by updating our previous guidelines. The symptoms of IC and BPS, collectively called as hypersensitive bladder (HSB) symptoms, are virtually indistinguishable between IC and BPS; however, IC and BPS should be considered as a separate entity of disorders. We define IC as a bladder disease with Hunner lesions, usually associated with HSB symptoms and bladder inflammation, and BPS as a condition with HSB symptoms in the absence of Hunner lesions and any confusable diseases. Pathophysiology totally differs between IC and BPS. IC involves immunological inflammation probably resulting from autoimmunity, while BPS is associated with the interaction of multiple factors such as neurogenic inflammation, exogenous substances, urothelial defects, psychological stress, and neural hyperactivity. Histopathology also differs between IC and BPS. IC is associated with severe inflammation of the whole bladder accompanied by plasma cell infiltration and urothelial denudation, while BPS shows little pathological changes. Management should begin with a differential diagnosis of IC or BPS, which would require cystoscopy to determine the presence or absence of Hunner lesions. The patients should be treated differently based on the diagnosis following the algorithm, although pain management would be common to IC and BPS. Clinical studies are also to be designed and analyzed separately for IC and BPS.