Toward a Precise Definition of Interstitial Cystitis: Further Evidence of Differences in Classic and Nonulcer Disease

PURPOSE: Interstitial cystitis is a bothersome condition in urological practice. There is continuous discussion on the extent and demarcation of this syndrome. Accumulated evidence indicates that interstitial cystitis is a heterogeneous syndrome. Today it is often divided into classic and nonulcer disease. Compared with classic interstitial cystitis the nonulcer type appears different in terms of demographic, endoscopic and histological findings as well as in the response to various types of treatment. However, in clinical series subdivision is not always performed, which makes it difficult to draw conclusions. We determined whether there are additional dissimilarities in clinical presentation in the 2 subtypes of interstitial cystitis. MATERIALS AND METHODS: We evaluated 130 patients with classic and 101 with nonulcer interstitial cystitis diagnosed according to National Institute for Diabetes and Digestive and Kidney Diseases criteria by surveying the clinical records, including voiding diaries. RESULTS: Patients with nonulcer disease were younger at diagnosis (p <0.0001) and at symptom onset. Furthermore, there was a marked and significant difference in bladder capacity while patients were under general anesthesia (p <0.0001). CONCLUSIONS: The current findings together with previous findings clearly demonstrate that the 2 subtypes of interstitial cystitis represent separate entities. We suggest refining the National Institutes of Health-National Institute for Diabetes and Digestive and Kidney Diseases criteria, so that subtyping scientific materials is considered mandatory, hence, ensuring that the 2 subtypes are evaluated separately in clinical studies.