Interstitial cystitis (IC/BPS), also known as bladder pain syndrome, is a chronic condition characterized by discomfort, pressure, or pain in the bladder and pelvic region, along with urinary urgency and frequency. These symptoms typically persist for at least six weeks and are not caused by infection or other identifiable conditions. Diagnosing IC/BPS is challenging because its symptoms overlap with many other bladder disorders, and there is no single definitive test. A thorough diagnostic process is essential to systematically rule out other potential causes.
Initial Evaluations
The diagnostic process for IC/BPS typically begins with a thorough initial evaluation by a healthcare provider, focusing on symptom assessment and ruling out common conditions. A detailed patient history is paramount, where the provider gathers information about the duration, frequency, and severity of urinary symptoms, as well as any potential triggers. Patients may be asked to complete symptom questionnaires or keep a bladder diary to track voiding patterns and pain levels, providing objective data for assessment.
A physical examination follows, including abdominal palpation for tenderness. For women, a pelvic exam assesses pelvic organs, while for men, a rectal exam evaluates the prostate. This examination identifies other conditions that might cause similar pain or discomfort, such as vaginitis, urethritis, or prostatitis, and assesses for muscle tenderness or structural issues.
Urinalysis and urine culture are fundamental initial tests. Urinalysis checks for the presence of blood, white blood cells, or other abnormalities in the urine. A urine culture specifically identifies if a bacterial infection, such as a urinary tract infection (UTI), is present. Negative urine cultures are a key indicator when considering an IC/BPS diagnosis, as IC/BPS is not caused by infection.
Urine cytology involves examining urine under a microscope for abnormal cells. This test is primarily used to screen for bladder cancer or precancerous conditions, as these can also cause bladder-related symptoms. While urine cytology alone does not diagnose cancer, it helps to rule out malignancies that might mimic IC/BPS symptoms.
Advanced Diagnostic Procedures
When initial evaluations do not yield a clear diagnosis and interstitial cystitis remains a strong possibility, a urologist or urogynecologist may perform more specialized procedures. One such procedure is cystoscopy, which involves inserting a thin tube with a camera through the urethra to visually examine the bladder lining. During cystoscopy, the doctor looks for specific findings that are sometimes associated with IC/BPS, such as pinpoint hemorrhages called glomerulations or distinctive inflamed patches known as Hunner’s lesions. While Hunner’s lesions are considered diagnostic for IC/BPS when present, they are uncommon, appearing in only about 5% to 10% of cases. Glomerulations are more common but are not specific to IC/BPS and can be seen in other conditions or even in individuals without symptoms.
Cystoscopy is often performed with hydrodistention, a procedure where the bladder is filled with fluid under controlled pressure while the patient is under anesthesia. This stretches the bladder wall, allowing for a more thorough visual inspection and sometimes revealing glomerulations or other bladder wall changes that might not be visible otherwise. Hydrodistention also has a therapeutic aspect, as stretching the bladder can provide temporary symptom relief for some individuals, though the exact mechanism is not fully understood. The procedure also allows for the measurement of bladder capacity under anesthesia, which can be reduced in IC/BPS.
During cystoscopy, a bladder biopsy may be taken. This involves removing small tissue samples from the bladder wall for microscopic examination. The primary purpose of a biopsy in the context of suspected IC/BPS is to rule out other conditions, such as bladder cancer or chronic infections, rather than to confirm IC/BPS itself. While a biopsy does not directly diagnose IC/BPS, it is a crucial step in excluding alternative explanations for bladder symptoms.
Urodynamic studies assess bladder function, including its ability to store and empty urine. These tests measure bladder pressure, urine flow rate, and bladder capacity to identify bladder dysfunction. Urodynamic studies help differentiate IC/BPS from other conditions like overactive bladder or bladder outlet obstruction by providing information about how bladder muscles and nerves function.
The potassium sensitivity test (PST) was historically used as a diagnostic tool for IC/BPS. This test involves instilling solutions of water and then potassium chloride into the bladder. A positive result, indicated by increased pain or urgency with the potassium solution, was thought to suggest a compromised bladder lining. However, the PST is now considered controversial and is not routinely recommended due to its invasiveness, potential to cause severe pain, and lack of specificity, as it can yield positive results in other bladder conditions.
The Diagnostic Journey
The diagnosis of interstitial cystitis is primarily a diagnosis of exclusion. This means that a definitive diagnosis is made not by a single confirmatory test, but by systematically ruling out other conditions that could be causing similar bladder and pelvic pain symptoms. The process requires careful consideration of a patient’s symptoms in combination with the results of various tests.
Healthcare providers must rule out common conditions like urinary tract infections, sexually transmitted infections, kidney stones, and bladder cancer. For women, endometriosis or vulvodynia are considered. In men, chronic prostatitis or benign prostatic hyperplasia must be investigated.
An IC/BPS diagnosis is established when persistent bladder pain, urgency, and frequency have been present for at least six weeks, and a comprehensive evaluation has excluded other identifiable causes. Advanced procedures like cystoscopy and urodynamic studies provide insights into bladder health and function, primarily supporting the diagnosis by ruling out other disorders.
Once an IC/BPS diagnosis is established, working with a specialist, such as a urologist or urogynecologist, is important. These specialists help develop a personalized management plan aimed at alleviating symptoms and improving quality of life.