Interstitial Cystitis
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Direct answer
Interstitial cystitis, now usually called bladder pain syndrome, is chronic (more than six weeks per American Urological Association guidance) suprapubic pain or pressure perceived to relate to the bladder, accompanied by urinary frequency and urgency in the absence of infection or another identifiable cause. Diagnosis is one of exclusion — urine culture, cytology in risk groups and cystoscopy to rule out carcinoma and tuberculosis — with Hunner ulcers and glomerulations on hydrodistension supporting the diagnosis in a minority. Treatment follows a stepped ladder from lifestyle changes and oral agents such as pentosan polysulfate and amitriptyline, through intravesical dimethyl sulphoxide, to botox and, rarely, major surgery.
What you must remember
- The AUA guideline triggers a basic evaluation once symptoms have persisted beyond six weeks — earlier than older six-month definitions — to avoid the historical years-long diagnostic delay.
- Classic triad: pain relieved (at least partly) by voiding, frequency, and nocturia; many patients void more than 15-20 times a day.
- Hunner ulcers — red patches with a sharply demarcated border and central fibrin — are seen in only about 10 per cent of patients but respond well to fulguration.
- Glomerulations (petechial haemorrhages) after hydrodistension are supportive but not specific; they also occur in normal bladders.
- Potassium sensitivity testing is rarely used now; the diagnosis is clinical after exclusion of mimics.
- First-line: stress reduction, dietary avoidance of acidic or spicy foods, caffeine and potassium-rich items; second-line: pentosan polysulfate 100 mg three times daily, amitriptyline, or cimetidine; intravesical dimethyl sulphoxide (RIMSO-50) remains the classic instillation agent.
- Ciclosporin A is the potent oral option for refractory disease; major surgery (augmentation, diversion, even cystourethrectomy) is a last resort for a small, strictly selected group.
A typical exam case
A 38-year-old woman gives a five-year story of worsening suprapubic burning, voiding 20 times daily and three times nightly; multiple antibiotic courses and antifungals have changed nothing, and repeated cultures are sterile. Work through her systematically. First, confirm the syndrome: symptom score tools (such as O'Leary-Sant ICIPI/ICPI indices), a frequency-volume chart, and urinalysis with culture. Second, exclude the dangerous mimics — carcinoma in situ of the bladder can produce exactly this picture in older patients, so urine cytology and cystoscopy with biopsies are mandatory in anyone over about 40 or with risk factors; in India, also send early-morning urines for tuberculosis, which is a far commoner cause of a painful frequency-sterile pyuria picture. Third, characterise: cystoscopy under anaesthesia with hydrodistension at 80 cm of water pressure looking for Hunner ulcers and diffuse glomerulations, and assessment of bladder capacity under anaesthesia (a small capacity suggests a more severe phenotype). Fourth, treat in steps: education and diet, then oral pentosan polysulfate or amitriptyline for 3-6 months, then intravesical DMSO weekly for six weeks; fulgurate any Hunner ulcer found. Fifth, escalate only on failure — intradetrusor botulinum toxin with caution about retention, neuromodulation, ciclosporin under supervision, and only very exceptionally urinary diversion or cystectomy.
How the exam frames it
Examiners love the exclusions more than the treatment: a stem describing a woman with "sterile pyuria, frequency and a shrunken bladder" is far more likely to be tuberculosis in an Indian setting than interstitial cystitis — the discriminators are pyuria (against BPS) and response to antitubercular therapy. The second trap is overcalling glomerulations: they are not diagnostic and do not mandate treatment. A frequently repeated viva line: Hunner ulcer = ulcerative phenotype (about 10 per cent), which is the subgroup that benefits most from endoscopic treatment and that can progress to a small fibrotic bladder. Finally, remember that pain persisting after cystectomy with a preserved urethra suggests the pain source was pelvic floor or neural, not the bladder — a sobering point that explains why surgery is the last rung of the ladder.
Frequently asked questions
How is interstitial cystitis distinguished from chronic cystitis?
Chronic bacterial cystitis has positive cultures and responds to antimicrobials; BPS by definition has sterile urine, no infection and no other identifiable pathology after full evaluation including cystoscopy.
What is the role of cystoscopy with hydrodistension?
It excludes carcinoma in situ, tuberculosis and other lesions, and identifies Hunner ulcers or glomerulations; it is part of evaluation rather than an obligatory diagnostic test in every patient.
Which oral drug is most characteristic of BPS treatment?
Pentosan polysulfate, a glycosaminoglycan analogue intended to repair the defective bladder lining, dosed 100 mg three times daily; amitriptyline at night is the other commonly used agent.
What is a Hunner ulcer and why does it matter?
A distinct inflammatory ulcer seen at cystoscopy in roughly 10 per cent of patients; it defines a more severe phenotype and can be treated directly by fulguration or injection of steroid, often with good symptomatic relief.
Is surgery ever indicated in interstitial cystitis?
Rarely — only for refractory, strictly ulcerative disease with a very small bladder; options include augmentation, diversion and cystectomy, and outcomes are unpredictable because pain may persist.