The diagnostic criteria for IC, agreed to in the mid 1980's at an NIDDK conference, was developed for research purposes. These criteria require cystoscopy with hydrodistention in the operating room under general anesthesia. There also are multiple exclusionary criteria for diagnosis which limit its utility. The end result is that up to 60% of cases of IC can be missed using NIDDK criteria for the diagnosis of IC2. Because of these limitations, cystoscopy is now used less often for diagnosis.