To report the reasons patients with interstitial cystitis/painful bladder syndrome (IC/PBS) give for the perception that the bladder is the source of their pain. The perception that the bladder is the source of pain is a necessary criterion for many definitions of IC/PBS.

Events Preceding Interstitial Cystitis was a case-control study seeking risk factors for IC/PBS. The inclusion criteria for incident cases included “lower abdominal pain” or “bladder pain” and ≥2 of the following symptoms: urinary frequency, urgency, and/or nocturia. The patients were systematically followed and at 18 months after the baseline interview were asked an open-ended question about their reasons for perceiving the bladder to be the source of their pain.

Of the 179 patients with current pain, 164 (92%) claimed ≥1 bladder or lower urinary tract symptoms caused them to perceive that their pain involved the bladder. Of these, 41% noted a “bladder” location for their pain; 34% noted pain increasing with bladder filling and/or decreasing with bladder emptying; 31% claimed the presence of urgency and/or frequency; 23% described worsened pain during and/or after urination; and 17% mentioned other urinary symptoms. Finally, 8% noted only nonurinary symptoms (4 patients) or “do not know” (11 patients).

No predominant reason was found that patients with IC/PBS gave for suspecting the bladder to be the source of pain. The common reasons included pain location, changes with the urinary cycle, and an association with other urinary symptoms. To clarify the relationship of IC/PBS to other chronic pain syndromes, which often are comorbidities, these features of IC/PBS should be queried.