Interstitial cystitis (IC) is a syndrome of pelvic and/or perineal pain, urinary urgency, and frequency. It is now agreed that IC is a multifactorial syndrome, not a single condition. A variety of etiologies for IC have been proposed, but none has been definitively proven. Since the etiologies for IC remain unknown, the current treatments are empiric. This article will review the major theories of etiology for IC and discuss the current treatment options with relevance to the proposed etiologies. No single treatment is effective for all IC patients. Therefore, the approach is to try different treatments, alone or in combination, until symptom relief is satisfactory. In some cases, none of the empiric IC treatments are successful. These patients require adjunctive pain management, and a small minority of IC patients resort to surgery if all other options fail.