It is recommended that patients experiencing symptoms of interstitial cystitis (IC) notify their physician. Diagnosis of the condition typically begins with a complete medical history. Patients will be asked to describe their symptoms including how long they have experienced them and their severity. Patients also may be asked to answer a short questionnaire called the Pelvic Pain Urgency/Frequency (PUF) survey to help the physician identify if the pelvic pain is coming from the bladder. In some cases, the patient will be instructed to maintain a written record detailing the frequency of fluid intake and urination (bladder diary), also known as an intake and output log. A pelvic examination will be part of the evaluation for female patients.

The symptoms of IC closely resemble those of other urinary system disorders, and no diagnostic test can conclusively identify IC in patients. For these reasons, IC is considered a diagnosis of exclusion. Physicians must rule out conditions such as endometriosis, sexually transmitted diseases (e.g., herpes), urinary tract infection, kidney stones, bladder cancer, irritable bowel syndrome (IBS) and others before diagnosing interstitial cystitis. It is important to note that some conditions, such as endometriosis, can coexist with IC. Physicians will use appropriate diagnostic tests to determine which conditions may be present in addition to IC.

To exclude other conditions and diagnose IC, physicians typically use urine tests including a urine culture, a prostate secretion culture (in men) and procedures such as cystoscopy. During a cystoscopy, the patient is anesthetized while the physician uses a hollow, lighted tube with several lenses (cystoscope) to view the inside of the bladder and urethra. At this time, a liquid (generally saline) is released into the bladder to stretch (distend) the organ to its limits. Cystoscopy can detect inflammation, thickness and stiffness of the bladder wall and the presence of Hunner’s ulcers. These are large sores in the bladder wall, which occur in only 5 to 10 percent of cases.

When the bladder is completely distended, areas of pinpoint bleeding, known as glomerulations, may be identified. The physician may also choose to remove a tissue sample (biopsy) at this time to confirm if inflammation is present and rule out the possibility of bacterial infections and bladder cancer.

The KCL test is another diagnostic procedure that some physicians may use to test for IC and evaluate a patient’s potential response to treatments such as medications that work on the bladder lining. For the KCL test, a catheter is used to fill the bladder with a potassium chloride solution. The solution may reveal deficiencies in the layer of the bladder wall. However, the test is painful and may be only 60 to 75 percent accurate. The KCL test is not widely used to diagnose IC.

On average, individuals with IC typically experience symptoms for approximately four years before being definitively diagnosed with the condition, according to the Mayo Clinic. Patients are diagnosed with IC when:

• Urinary frequency, urgency and/or pain in the bladder, pelvic area or genitalia are present.
  
  
• Cystoscopy results confirm that the bladder wall is inflamed and Hunner’s ulcers or glomerulations are present.
  
  
• Other conditions that could cause the symptoms have been ruled out.