What is interstitial cystitis?

What is Interstitial Cystitis?

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic condition defined by an unpleasant sensation (pain, pressure, or discomfort) perceived to be related to the urinary bladder, associated with lower urinary tract symptoms lasting more than six weeks, in the absence of infection or other identifiable causes. 1, 2

Core Clinical Features

Pain as the Hallmark Symptom

• Pain, pressure, or discomfort is the defining characteristic that distinguishes IC/BPS from other bladder conditions like overactive bladder 1, 2
• Pain is typically felt in the suprapubic region but commonly extends throughout the pelvis—including the urethra, vulva, vagina, rectum—and to extragenital locations such as the lower abdomen and back 1
• Many patients use the word "pressure" rather than "pain" and may actually deny having pain, making it critical to use broad descriptors when evaluating symptoms 1, 2
• Pain characteristically worsens with bladder filling and improves with urination 1, 2
• Pain may be exacerbated by specific foods or drinks 1

Associated Urinary Symptoms

• Urinary frequency is nearly universal (92% of patients) but does not distinguish IC/BPS from other lower urinary tract disorders 1
• Urinary urgency occurs in 84% of patients but differs qualitatively from overactive bladder urgency 1
• IC/BPS patients experience a more constant urge to void and void to avoid or relieve pain, whereas overactive bladder patients void to avoid incontinence 1, 2
• Nocturia is common and contributes significantly to quality of life impairment 1

Diagnostic Criteria and Timeline

• Symptoms must be present for at least six weeks with documented negative urine cultures to establish the diagnosis 1, 2
• This six-week threshold allows for earlier treatment initiation compared to older definitions requiring longer symptom durations 2
• IC/BPS is fundamentally a diagnosis of exclusion—infections and other identifiable causes must be ruled out 1, 2

Presentation in Men

• Historically considered rare in men (female-to-male ratio of 10:1), but male IC/BPS may be more common than previously recognized 1
• The diagnosis of IC/BPS should be strongly considered in men with pain, pressure, or discomfort perceived to be related to the bladder and associated with urinary frequency, nocturia, or urgent desire to void 1, 2
• Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) shares nearly identical clinical characteristics with IC/BPS 1, 2
• CP/CPPS is characterized by pain in the perineum, suprapubic region, testicles, or tip of the penis, often exacerbated by urination or ejaculation 1
• Some men meet criteria for both IC/BPS and CP/CPPS, and treatment approaches can include therapies for both conditions 1, 2

Diagnostic Approach

• Diagnosis requires careful history, physical examination, and laboratory testing to document symptoms and exclude other disorders 1
• Document the number of voids per day, sensation of constant urge to void, and the location, character, and severity of pain, pressure, or discomfort 1
• Record dyspareunia, dysuria, ejaculatory pain in men, and relationship of pain to menstruation in women 1
• Perform a brief neurological exam to rule out occult neurologic problems and evaluate for incomplete bladder emptying to rule out occult retention 1
• Urine culture is essential even in patients with negative urinalysis to detect lower levels of bacteria that may not be readily identifiable with dipstick or microscopic exam 1

Role of Cystoscopy

• There are no agreed-upon cystoscopic findings diagnostic for IC/BPS; the only consistent cystoscopic finding that leads to a diagnosis is the appearance of Hunner lesions 1
• Cystoscopy should be performed in patients for whom Hunner lesions are suspected, as this is the only reliable way to diagnose their presence 1, 2
• Cystoscopy is also indicated when clinical mimics such as bladder cancer, bladder stones, or intravesical foreign bodies are suspected 1

Urodynamics

• There are no agreed-upon urodynamic criteria diagnostic for IC/BPS 1
• Urodynamics are not recommended for routine clinical use to establish an IC/BPS diagnosis 1, 2
• Specific indications where urodynamic evaluation may be useful include suspicion of outlet obstruction in either sex, possibility of poor detrusor contractility, or other conditions that could explain why patients are refractory to behavioral or medical therapies 1

Heterogeneity and Phenotypes

• IC/BPS is a heterogeneous clinical syndrome with subgroups or phenotypes within the condition 1
• Patients present with a wide spectrum of symptoms, physical exam findings, and clinical test responses 1
• This complexity causes significant misdiagnosis, underdiagnosis, and delayed diagnosis 1, 2
• No single treatment reliably benefits most or all patients, and most treatments may benefit only a subset of patients that is not readily identifiable before treatment 1

Common Diagnostic Pitfalls

• Do not use research or clinical trial definitions (such as NIDDK criteria) in clinical practice, as these are not appropriate outside of clinical trials and can lead to misdiagnosis or delays in treatment 1, 2
• Do not treat with antibiotics when no infection is present, as this can lead to antibiotic resistance and disruption of protective flora 2
• Failing to recognize that patients may describe symptoms as "pressure" rather than "pain" can lead to missed diagnoses 1, 2
• Assuming all urgency and frequency represent overactive bladder without assessing for pain can result in inappropriate treatment 1, 2