Aug 10, 2010
While there are a number of diagnostic criteria for IC/PBS, there is no agreed upon gold-standard test that reliably makes the diagnosis. IC is therefore mostly a clinical diagnosis based on symptoms and signs, although, a number of tests are helpful. On first impression, the diagnosis of IC would seem to be straightforward. However, early in the course of the disease, IC can be more difficult to diagnosis. Studies suggest that 90% of patient who have IC have only one symptom in the beginning. Most patients will take 2 to 5 years to manifest the classic signs of IC/PBS. These include Pelvic Pain, Urinary Frequency, Urinary Urgency, Tenderness of the Urinary Bladder during exam, Frequent Voids at night. Another complicating factor is that symptoms are often episodic early in the disease.
Most patients are treated for multiple Urinary Tract Infections with antibiotics early in the disease and many report responding to therapy. However, the response is not due to the therapy, but more likely, due to the normal waxing and waning of symptoms that occur in early disease. Awareness of this disease is essential if early diagnosis is to be made.
Chronic Pelvic Pain and Painful Intercourse are common symptoms often associated with diseases such as Endometriosis and Uterine Fibroids. Unfortunately, they are also common symptoms of Interstitial Cystitis (Painful Bladder Syndrome) in women. One study found 80% of women who had persistent chronic pelvic pain after hysterectomy had interstitial cystitis.
The diagnosis Interstitial Cystitis is one of exclusion. Other causes of pelvic pain, frequent voids at night, urinary frequency and urgency must be eliminated. Urinalysis and culture, are essential tests and a pelvic ultrasound should be performed. Any abnormalities found should be investigated fully. For many years, Cystoscopy (looking into the bladder with a small scope) with distending of the urinary bladder under anesthesia was considered the “gold-standard”. Recent data suggests this test may not be as helpful as once thought. Studies have found some patients showing positive findings (Glomerulations) were not symptomatic for IC and other patients that were symptomatic, did not have positive findings. Still, cystoscopy is useful and should be included as part of the workup.
Potassium sensitivity testing (PST) may be useful in the diagnosis of IC in patients who present with complicated histories. The instillation of potassium into the bladder causes the patient to experience an increase in pain and/or frequency if the test is positive. It is believed this occurs due to a defect in the protective layer in the bladder that allows the potassium and/or urine cause pain receptors to react.
Two screening questionnaires are available to help with the diagnosis of IC/PBS. One is the O’Leary-Sant, which is often used in research settings, and the other is the Pelvic Pain and Urgency Frequency Symptom Scale, or PUF questionnaire, most often used in clinical practice. Click Here for a link to the PUF Questionnaire.
Any combination of the above test and questionnaires may be required to accurately make the diagnosis of IC.
J. Kyle Mathews, MD
Plano Urogynecology Associates
Plano OBGyn Associates