Interstitial cystitis (IC) has remained an unresolved problem in clinical urology. The etiology and pathophysiologic mechanisms of IC are still undetermined, and to date the diagnosis is based on the clinical characteristics of the disease and the exclusion of other diseases and pathology that can mimic the symptoms of IC. In clinical practice, much emphasis has been placed on finding a specific etiology and specific pathologic markers for the disease and on identifying specific events that precipitate IC; however, those have not been identified with certainty. In this review, an additional approach is proposed, taking into account the observation that IC shares many features with other chronic nonmalignant visceral pain syndromes. This approach is based on the conceptualization of 3 hypotheses: (1) a spectrum of different insults can lead to chronic visceral pain in patients with IC; (2) different underlying pathogenic pain mechanisms may require different pain treatment strategies for patients diagnosed with IC; and (3) multiple different pathogenic pain mechanisms may coexist in the same patient requiring several different pain treatment strategies (perhaps concomitantly) to successfully treat chronic visceral pain associated with IC. This concept is likely to lead to new insights into the pathophysiologic mechanisms of IC and to novel treatment avenues for patients with IC and - in a broader view - also for patients with other chronic visceral pain syndromes. © 2001, Elsevier Science Inc.