Living with interstitial cystitis (IC) or painful bladder syndrome (PBS) raises many questions. The condition is poorly understood, symptoms vary wildly between individuals, and what works for one person may do nothing for another. This FAQ addresses the questions that IC/PBS patients most commonly ask, drawing on current medical understanding and clinical experience.

Why do so many IC sufferers also have irritable bowel syndrome, fibromyalgia, and allergies?

This is one of the most striking patterns in IC/PBS research, and frustratingly, nobody has a definitive explanation for it. Studies consistently show that IC patients have higher rates of other chronic conditions compared to the general population. Research published in The Journal of Urology found that IC patients were significantly more likely to have irritable bowel syndrome (IBS), fibromyalgia, chronic fatigue syndrome, and various allergic conditions 1.

The statistics are quite remarkable. Approximately 40% of IC patients meet diagnostic criteria for IBS, and an estimated 75% report some form of allergy or atopic condition. The overlap with fibromyalgia is so common that some researchers have proposed these conditions share underlying mechanisms.

Several theories attempt to explain these connections:

The mast cell hypothesis: One leading theory centres on mast cells, which are specialised immune cells found throughout the body’s tissues. When activated, mast cells release inflammatory chemicals including histamine, cytokines, and other substances that cause pain and inflammation. Mast cells are found in increased numbers in the bladder walls of IC patients, but they also appear in the gut (potentially explaining IBS) and throughout connective tissue (potentially explaining fibromyalgia pain). Some researchers believe a systemic tendency toward mast cell activation might underlie multiple conditions simultaneously 2.

Sensitised nervous system: Another possibility is that IC and these other conditions all involve central sensitisation, where the nervous system becomes hypersensitive to pain signals. Once central sensitisation occurs, it can affect multiple organ systems, potentially explaining why so many chronic pain conditions cluster together.

Shared inflammatory pathways: There may be common immunological or inflammatory processes driving multiple conditions. Research is ongoing, but early findings suggest overlapping patterns of inflammatory markers between IC, IBS, and fibromyalgia.

My honest take: we simply do not know why these conditions cluster together so frequently. The fancy diagnostic labels disguise our ignorance about the underlying causes. It is possible they are all manifestations of the same disease process expressed in different organs. Until we understand the root causes better, we are left managing symptoms rather than addressing fundamental mechanisms.

Are there different types of interstitial cystitis?

There are certainly different presentations of IC, and whether these represent truly distinct conditions or variations of the same disease remains debated.

What we call IC is really a diagnosis of exclusion. Patients receive this label once other causes of cystitis have been ruled out, including bacterial infections, bladder cancer, and other identifiable pathologies. This means the IC diagnostic category likely contains multiple subgroups with different underlying causes.

Clinically, two main types have been traditionally distinguished:

Ulcerative (classic) IC: Characterised by Hunner’s lesions or ulcers visible during cystoscopy. This affects perhaps 5 to 10% of IC patients and tends to present with more severe symptoms and smaller functional bladder capacity.

Non-ulcerative IC: The more common form, where the bladder lining shows inflammation and glomerulations (pinpoint bleeding) during hydrodistension but no ulcers. This category is likely the most heterogeneous, potentially containing multiple distinct subtypes.

Research from the MAPP (Multidisciplinary Approach to the Study of Chronic Pelvic Pain) network has identified symptom clusters suggesting IC/PBS may include subgroups with bladder-focused pain versus more widespread pelvic pain, and groups with or without significant pelvic floor dysfunction 3.

Why does this matter for patients? Because different IC subtypes may respond differently to treatments. Someone with significant pelvic floor involvement might benefit more from physiotherapy, while someone with primarily bladder-based symptoms might respond better to bladder instillations. Unfortunately, we cannot yet reliably match patients to treatments based on subtype, but research is moving in this direction.

What can help severe urethral burning after urinating?

Urethral burning is one of the most distressing IC symptoms, and unfortunately there is no universal remedy because multiple different causes can produce similar sensations.

First, it is worth checking for conditions that can be specifically treated:

Urinary tract infection: Even if you have IC, you can still develop bacterial infections. A urine culture can confirm or rule this out.
Vulvovaginal conditions: In women, infections or inflammatory conditions affecting the vulva or vagina can cause burning that feels urethral. Herpes simplex virus infection, lichen sclerosus, and atrophic vaginitis should be considered.
Bladder stones: These can cause burning and irritation, diagnosed via imaging.

If no specific cause is found, symptomatic approaches include:

Urinary alkalinisers: Products that make urine less acidic may reduce irritation. Potassium citrate or sodium citrate preparations are available, though they should be used cautiously and not long-term without medical supervision.

Topical numbing agents: Some patients find relief from lidocaine-based products applied to the urethral opening. This is not a long-term solution but can help during flares.

Bladder instillations: If burning relates to bladder lining irritation, treatments like Cystistat (sodium hyaluronate) or DMSO instilled directly into the bladder may help by coating and protecting the bladder lining.

Urethral dilation: Occasionally, a minor procedure to gently stretch the urethra provides relief, though this is not appropriate for everyone and should only be performed by a urologist who has thoroughly evaluated your specific situation.

Why can they not just transplant bladders?

This is a reasonable question. If heart, lung, and kidney transplants are possible, why not bladders?

The short answer is that bladder dysfunction, while miserable, is not life-threatening in the way that heart or kidney failure can be. Organ transplantation carries substantial risks, including rejection requiring lifelong immunosuppressive drugs that increase vulnerability to infections and certain cancers. These trade-offs make sense when the alternative is death. They make much less sense for a condition that, however difficult, is not going to kill you.

The longer answer involves practical surgical alternatives. When a bladder is truly non-functional and causing intolerable symptoms despite all other treatments, surgeons can create a neobladder using segments of the patient’s own bowel. This avoids rejection issues entirely. The surgically constructed reservoir is not a perfect bladder, but it allows urine storage and controlled emptying.

Some IC patients do eventually opt for bladder removal (cystectomy) with urinary diversion or neobladder construction, but this is generally considered a last resort after years of failed conservative treatments. The surgery is major, recovery is lengthy, and outcomes vary.

Why does anxiety make my bladder symptoms worse?

The connection between stress, anxiety, and bladder symptoms is well-documented and affects people with and without IC. The mechanism involves the autonomic nervous system, which regulates involuntary bodily functions including bladder filling and emptying.

During periods of stress or anxiety, the body’s sympathetic nervous system (the “fight or flight” response) becomes activated. This triggers complex effects on the bladder including altered blood flow, changes in sensation, and increased muscle tension in the pelvic floor. For someone who already has a sensitised bladder with reduced capacity, these changes become much more noticeable.

Research has also shown bidirectional relationships between chronic pain conditions and anxiety. Chronic pain causes anxiety, and anxiety can amplify pain perception through central nervous system mechanisms 4.

For IC patients with small functional bladder capacity, stress-induced urgency creates practical problems, as you clearly experience with situations like dental visits or travel.

Anti-anxiety medications are occasionally helpful but carry their own side effects and dependency risks. Non-pharmacological approaches often work better for managing this aspect of IC:

Bladder retraining: Gradual scheduled voiding to extend intervals between bathroom visits
Relaxation techniques: Breathing exercises, meditation, or progressive muscle relaxation
Pelvic floor physiotherapy: Many people unconsciously tense pelvic floor muscles during stress, worsening urgency
Planning ahead: Reducing anxiety by knowing where toilets are located before stressful events

The best approach combines these strategies with your standard IC treatments rather than relying solely on anti-anxiety medication.

Can Amitriptyline stop working over time?

Yes, the body can develop tolerance to amitriptyline, though this varies considerably between individuals. Some patients maintain benefit for years on stable doses, while others notice declining effectiveness after months or a few years.

Amitriptyline belongs to a class called tricyclic antidepressants. At the low doses used for chronic pain conditions (typically 10 to 50 mg at night, much lower than antidepressant doses), it works through mechanisms including blocking certain pain signal pathways and affecting neurotransmitter levels.

When tolerance develops, options include:

Dose adjustment: A modest increase may restore effectiveness
Drug holidays: Some clinicians recommend brief breaks from the medication, though this should only be done under medical supervision given that abrupt discontinuation can cause withdrawal symptoms
Switching medications: Other tricyclic antidepressants like nortriptyline may work, or completely different drug classes like gabapentinoids (pregabalin, gabapentin) might be tried

About 35% of IC patients obtain meaningful symptomatic relief from amitriptyline. If you have been in that group and notice declining benefit, discuss options with your prescribing clinician rather than simply increasing the dose yourself or stopping abruptly.

Does Atarax (Hydroxyzine) working mean my IC is caused by allergy?

Not necessarily. Hydroxyzine (sold as Atarax or Vistaril) is an antihistamine that appears helpful for many IC patients, but its mechanisms extend beyond simple allergy blocking.

Hydroxyzine’s chemical structure resembles tricyclic antidepressants like amitriptyline. This means it has additional actions beyond blocking histamine receptors, including effects on pain signalling pathways and potential anxiolytic (anxiety-reducing) properties.

In IC, hydroxyzine likely works by blocking histamine release from mast cells in the bladder wall. It may also interfere with nerve signalling that transmits pain and urgency sensations. These actions would benefit IC patients regardless of whether allergy is their primary problem.

That said, patients with known allergies or atopic conditions (eczema, asthma, hay fever) do seem to have somewhat higher response rates to hydroxyzine. If you have such a history and hydroxyzine helps you, allergy-related inflammation may indeed contribute to your particular IC presentation. But response to hydroxyzine does not prove an allergic cause, just as aspirin helping a headache does not prove the headache was caused by aspirin deficiency.

I have IC and severe constipation. Are they connected?

Constipation and IC frequently occur together, and the connection may work in both directions.

Anatomically, the bladder and rectum are adjacent in the pelvis. A full, distended rectum can physically press on the bladder, potentially worsening urgency and frequency symptoms.

Functionally, both organs share nerve pathways and pelvic floor muscle involvement. Dysfunction in the pelvic floor muscles can simultaneously affect bowel and bladder function. Patients who chronically tighten their pelvic floors (often unconsciously in response to pain) may develop both urinary symptoms and difficulty evacuating stool.

The medications used to treat IC can also cause constipation as a side effect. Tricyclic antidepressants like amitriptyline are notorious for this. Opioid pain medications, if prescribed, are even worse.

Addressing constipation often helps bladder symptoms as well:

Ensure adequate fibre intake (though be aware that some high-fibre foods may be bladder irritants for you)
Maintain good hydration despite natural reluctance to drink when bladder symptoms are severe
Consider stool softeners or osmotic laxatives if dietary measures are insufficient
Pelvic floor physiotherapy can address muscle dysfunction affecting both systems

If you have both conditions, it is worth mentioning this pattern to your healthcare providers, as coordinated treatment addressing both may be more effective than treating them separately.

Finding More Information

If you are newly diagnosed with IC/PBS or looking to optimise your management, the following resources on this site may be helpful:

Interstitial Cystitis condition page for a comprehensive overview
IC/PBS Diet information for guidance on identifying food triggers
Cystistat and DMSO for information on bladder instillation treatments
Painful Bladder Syndrome for the closely related diagnosis

The NHS also provides helpful guidance on interstitial cystitis symptoms, diagnosis, and treatment options 5.

References

Nickel JC, et al. Interstitial cystitis/painful bladder syndrome and associated medical conditions with an emphasis on irritable bowel syndrome, fibromyalgia and chronic fatigue syndrome. J Urol. 2010;184(4):1358-1363.
Theoharides TC, et al. Mast cells and inflammation. Biochim Biophys Acta. 2012;1822(1):21-33.
Lai HH, et al. Clustering of patients with interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome. J Urol. 2017;197(3):640-648.
Clemens JQ, et al. Mental health diagnoses in patients with interstitial cystitis/painful bladder syndrome and chronic prostatitis/chronic pelvic pain syndrome: a case/control study. J Urol. 2008;180(4):1378-1382.
NHS. Interstitial cystitis. https://www.nhs.uk/conditions/interstitial-cystitis/