What is interstitial cystitis?

What is Interstitial Cystitis?

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic bladder condition defined as 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

Core Clinical Features

Hallmark Symptom: Pain

• Pain is the defining characteristic that distinguishes IC/BPS from other bladder disorders. 1
• The pain encompasses a broad spectrum of descriptors—many patients use terms like "pressure" or "discomfort" and may actually deny using the word "pain." 1
• Pain locations extend beyond the suprapubic region to include the entire pelvis (urethra, vulva, vagina, rectum) and extragenital sites (lower abdomen, back). 1
• Pain characteristically worsens with bladder filling and improves with urination, and often intensifies with specific foods or drinks. 1, 2

Associated Urinary Symptoms

• Urinary frequency occurs in approximately 92% of patients, though it does not distinguish IC/BPS from other lower urinary tract disorders. 1
• Urgency affects about 84% of patients but differs qualitatively from overactive bladder—IC/BPS patients experience a more constant urge to void to relieve pain, whereas overactive bladder patients void to avoid incontinence. 1, 2
• Nocturia is nearly universal in affected patients. 1

Diagnostic Approach

Key Diagnostic Criteria

• Symptoms must persist for at least 6 weeks to allow earlier treatment initiation and prevent delays that occur with definitions requiring 6+ months. 1, 3
• Urine cultures must be negative—the absence of infection is essential to the diagnosis. 1, 4, 3
• The diagnosis remains one of exclusion after ruling out urinary tract infection, bladder cancer, and other identifiable pathology. 1

Clinical Presentation Patterns

• The diagnosis is challenging because patients present with a wide spectrum of symptoms, leading to significant misdiagnosis, underdiagnosis, and delayed diagnosis. 1
• Patients may initially report a single symptom such as dysuria, frequency, or pain, with symptom flares that suddenly intensify for hours, days, or weeks. 1, 3
• A history of recent culture-proven UTI can be identified in 18-36% of women at presentation, though subsequent cultures remain negative. 1, 3

Special Populations

Male Patients

• Historically considered rare in men (female-to-male ratio of 10:1), but the incidence may be higher than previously recognized. 1
• 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
• Significant overlap exists with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS)—some men meet criteria for both conditions simultaneously. 1, 4
• When both conditions coexist, treatment should include established IC/BPS therapies plus therapies more specific to CP/CPPS. 1, 4

Common Comorbidities

• IC/BPS frequently coexists with fibromyalgia, irritable bowel syndrome, chronic fatigue syndrome, Sjögren's syndrome, chronic headaches, and vulvodynia, suggesting possible systemic dysregulation. 1
• High rates of prior pelvic surgery (especially hysterectomy) and levator ani pain occur in women with IC/BPS, though these may represent missed diagnoses rather than causative factors. 1
• Mental health disorders including depression and anxiety are common, potentially sharing a common biological mechanism rather than being purely reactive. 1

Critical Diagnostic Pitfalls to Avoid

• Do not use research definitions (NIDDK criteria) in clinical practice—these are designed for clinical trials and will cause misdiagnosis and treatment delays. 1
• Do not dismiss patients who deny "pain"—many describe their symptoms as "pressure" or "discomfort" instead. 1
• Do not confuse IC/BPS urgency with overactive bladder urgency—IC/BPS patients void to relieve pain, not to prevent incontinence. 1, 2
• Do not treat with antibiotics when cultures are negative—IC/BPS is defined by the absence of infection. 4, 3
• Do not assume all pelvic pain with urinary symptoms in men is prostatitis—consider IC/BPS as a primary or coexisting diagnosis. 1, 4

Impact on Quality of Life

• IC/BPS causes significant disability with profound negative impacts on work, family life, and psychological well-being. 1, 5
• Sexual dysfunction is moderate to severe and occurs at high rates, with pain mediating sexual dysfunction and its associated effects on quality of life. 1
• Women with IC/BPS report significantly more pain and fear of pain with intercourse compared to controls, with rates diverging in adulthood despite similar adolescent sexual function. 1