Not All IC Is the Same:
Understanding IC/BPS Phenotypes

If you've been diagnosed with interstitial cystitis (IC), you may have noticed something confusing.

Two people can have the same diagnosis but experience completely different symptoms.

One person may feel intense bladder pain as their bladder fills.

Another may experience constant pelvic pressure, muscle tension, or discomfort during intercourse.

Someone else may have bladder symptoms alongside widespread pain, fatigue, or irritable bowel syndrome (IBS).

And while one treatment might provide significant relief for one person, it may do very little for another.

Why?

Because interstitial cystitis/bladder pain syndrome (IC/BPS) isn't necessarily one single condition with one underlying cause.

Researchers increasingly recognize that IC/BPS includes different clinical patterns, known as phenotypes, which may involve different biological mechanisms and respond differently to treatment.¹

Understanding these patterns may help explain why managing IC/BPS often requires a personalized approach.

What Are IC/BPS Phenotypes?

A phenotype is a recognizable pattern of symptoms, physical findings, and other clinical characteristics associated with a condition.

In IC/BPS, phenotyping helps healthcare providers look beyond the diagnosis itself to understand what may be contributing to someone's symptoms.

IC/BPS is generally characterized by persistent bladder-related pain, pressure, or discomfort, often accompanied by urinary urgency or frequency, without an infection or another identifiable condition that fully explains the symptoms.²

But these symptoms don't always arise from the same mechanisms.

Some people have more localized bladder involvement.

Others experience pelvic muscle dysfunction or changes in how their nervous system processes pain.

And some have identifiable inflammatory lesions within the bladder.

Recent research has highlighted four clinically useful patterns:

1. Bladder-centric IC/BPS

2. Hunner lesion IC

3. Widespread or centralized pain IC/BPS

4. Pelvic-floor-centric IC/BPS

These aren't always four completely separate categories. Hunner lesion disease is often considered part of the broader bladder-centric group, while pelvic floor dysfunction and widespread pain may overlap with other patterns.¹

The purpose of phenotyping isn't to place everyone into a rigid category.

It's to better understand which factors may be driving symptoms and which treatments are most likely to help.

1. Bladder-Centric IC/BPS: When Symptoms Are Focused on the Bladder

For some people, IC/BPS symptoms appear to originate primarily from the bladder itself.

This is often called the bladder-centric phenotype.

People with this pattern may experience pain that becomes more noticeable as the bladder fills and improves after urination.

Common features may include:

• Bladder pain or pressure that increases with filling

• Temporary relief after emptying the bladder

• Frequent urination to avoid discomfort

• Urinary urgency associated with pain

• Symptoms concentrated around the bladder rather than throughout the body

Researchers have proposed that bladder-centric IC/BPS may involve changes in the bladder lining, local inflammation, or increased sensitivity of bladder-associated nerves.¹˒³

However, these mechanisms aren't present or proven in every person.

Why Treatment May Look Different

When symptoms are primarily bladder-focused, treatments that directly target the bladder may be particularly relevant.

Depending on the individual, these may include:

• Identifying personal dietary or lifestyle triggers

• Bladder training when appropriate and tolerable

• Oral medications for symptom management

• Bladder instillations, which deliver medication directly into the bladder

• Other bladder-directed therapies recommended by a urologist

The goal is to reduce pain and improve bladder function without unnecessarily increasing treatment burden.

However, bladder-focused symptoms don't automatically mean that every bladder-directed treatment will work.

A person's response still depends on their individual presentation.

2. Hunner Lesion IC: A Distinct Inflammatory Pattern

Hunner lesion IC is one of the most clearly identifiable forms of IC/BPS.

Unlike other presentations, this phenotype involves visible inflammatory lesions within the bladder lining.

These lesions can be identified during cystoscopy, a procedure that allows a healthcare provider to examine the inside of the bladder.

Hunner lesions are not the same as ordinary bladder irritation.

They represent a distinct inflammatory finding and may be associated with more pronounced bladder inflammation and reduced bladder capacity.¹˒⁴

Common features may include:

• Significant bladder pain

• Urinary frequency and urgency

• Pain associated with bladder filling

• Reduced functional bladder capacity

• Inflammatory lesions visible during cystoscopy

Not everyone with IC/BPS has Hunner lesions.

And importantly, symptoms alone cannot reliably confirm whether they're present.

Why Treatment May Look Different

Hunner lesion IC is particularly important to identify because it has specific treatment options.

Rather than relying exclusively on general IC/BPS symptom management, healthcare providers may recommend procedures that directly treat the lesions.

These can include endoscopic fulguration, which uses controlled energy to treat affected tissue, or injection of triamcinolone into the lesions.²

Other treatments may be considered depending on symptom severity and response.

This is one of the clearest examples of why identifying an IC/BPS phenotype matters.

A treatment directed at Hunner lesions may be appropriate for someone with confirmed lesions but not for someone whose symptoms are primarily related to pelvic floor muscle dysfunction.

The diagnosis may sound similar, but the underlying clinical findings are different.

3. Widespread or Centralized Pain IC/BPS: When Pain Extends Beyond the Bladder

Not everyone with IC/BPS experiences pain that stays within the bladder or pelvis.

Some people also report pain in other areas of the body, along with symptoms such as fatigue, sleep disturbances, or increased sensitivity to discomfort.

This is often described as the widespread pain phenotype.

Researchers have found that some people with IC/BPS also experience chronic overlapping pain conditions, including:

• Fibromyalgia

• Irritable bowel syndrome (IBS)

• Chronic fatigue-related conditions

• Chronic headaches or migraines

• Other persistent pelvic or musculoskeletal pain conditions

These overlapping conditions have led researchers to investigate the role of central sensitization.¹˒⁵

What Is Central Sensitization?

Central sensitization refers to changes in how the central nervous system processes pain signals.

Normally, the nervous system helps detect potentially harmful stimuli and regulate pain responses.

But in some chronic pain conditions, pain-processing pathways may become more sensitive.

This can contribute to heightened pain responses or pain that extends beyond the original area of discomfort.

For someone with IC/BPS, this may mean bladder symptoms occur alongside pain in other parts of the body.

However, widespread pain doesn't automatically prove that central sensitization is present or that the bladder isn't contributing to symptoms.

Researchers are still working to better understand these relationships.

Why Treatment May Look Different

If pain involves broader nervous system processing, focusing exclusively on the bladder may not adequately address every symptom.

Treatment may involve a multidisciplinary approach, including:

• Medications that help regulate chronic pain

• Pain neuroscience education

• Gentle, individualized physical activity

• Sleep support

• Stress management strategies

• Psychological therapies that support chronic pain coping

• Treatment of overlapping conditions such as IBS or fibromyalgia

These approaches aren't intended to suggest that IC/BPS pain is psychological or imagined.

The pain is real.

Rather, they recognize that chronic pain can involve multiple biological systems, including the nervous system.

For some people, addressing these broader contributors may be just as important as treating bladder symptoms.

4. Pelvic-Floor-Centric IC/BPS: When Muscles Contribute to Pain

The pelvic floor is a group of muscles that supports the bladder, bowel, and reproductive organs.

These muscles also help coordinate urination and bowel movements.

But when pelvic floor muscles become overly tense, tender, or unable to relax properly, they can contribute to symptoms that resemble or accompany IC/BPS.

This is often called the pelvic-floor-centric or myofascial pelvic pain phenotype.

Common features may include:

• Pelvic pressure or aching

• Pain during or after intercourse

• Difficulty relaxing to urinate

• A sensation of incomplete bladder emptying

• Urinary urgency or frequency

• Tenderness or trigger points in the pelvic floor muscles

Research has identified pelvic floor tenderness and myofascial pain as important clinical features in a subgroup of people with IC/BPS.¹˒⁶

In some cases, pelvic floor dysfunction may develop in response to chronic bladder pain.

In others, pelvic muscle dysfunction may be a major contributor to symptoms from the beginning.

It's also possible for pelvic floor dysfunction to cause bladder-like symptoms without IC/BPS being the underlying diagnosis.

This is why a thorough assessment matters.

Why Treatment May Look Different

When pelvic floor muscle tension is a major contributor, treatment may focus on improving muscle relaxation, coordination, and mobility.

Pelvic floor physiotherapy may include:

• Manual therapy to address muscle tenderness

• Myofascial release techniques

• Relaxation and diaphragmatic breathing exercises

• Improving pelvic floor coordination

• Addressing related hip, abdominal, or pelvic muscle restrictions

A randomized multicentre trial found that myofascial physical therapy produced greater overall symptom improvement than general therapeutic massage in women with IC/BPS and pelvic floor tenderness.⁶

An important distinction is that pelvic floor therapy for this phenotype isn't necessarily about strengthening.

In fact, traditional Kegel exercises may worsen symptoms when the pelvic floor is already excessively tense.

The American Urological Association recommends appropriate manual physical therapy for patients with pelvic floor tenderness and advises against pelvic floor strengthening exercises in this setting.²

For someone whose symptoms are driven largely by pelvic muscle tension, learning to relax and coordinate those muscles may be more helpful than trying to strengthen them.

Can You Have More Than One IC/BPS Phenotype?

Absolutely.

Although researchers describe distinct patterns, many people experience overlapping features.

For example, someone with bladder-centric IC/BPS may also develop pelvic floor muscle tension from repeatedly guarding against pain.

Someone with Hunner lesions may experience secondary pelvic floor dysfunction.

And someone with widespread pain may also have bladder-specific triggers.

This overlap is one reason IC/BPS can be challenging to treat.

A single therapy may address one contributor without improving the others.

Researchers have increasingly emphasized that phenotypes should guide clinical decision-making rather than function as strict diagnostic categories.¹

The goal is to identify the most relevant symptom drivers and develop a treatment plan that addresses them together.

How Do Healthcare Providers Identify Your IC/BPS Phenotype?

There isn't one test that identifies every IC/BPS phenotype.

Instead, healthcare providers combine your medical history, symptom patterns, physical examination, and selected investigations.

They may ask questions such as:

• Does your pain increase as your bladder fills?

• Does urinating provide temporary relief?

• Is your pain limited to the bladder or present elsewhere?

• Do you experience pain during intercourse?

• Do you have difficulty relaxing your pelvic muscles?

• Do you also experience IBS, fibromyalgia, or other chronic pain conditions?

• Have you previously undergone cystoscopy?

A pelvic examination may help identify muscle tenderness or tension.

Cystoscopy may be recommended when Hunner lesions are suspected or when the diagnosis is uncertain.

Urinalysis, urine culture, and other investigations may also be necessary to rule out urinary tract infections and other conditions that can cause similar symptoms.²

It's important to remember that IC/BPS is generally diagnosed after other potential explanations have been considered.

Conditions such as recurrent urinary tract infections, endometriosis, overactive bladder, and pelvic floor dysfunction can overlap with IC/BPS symptoms.

Understanding the full clinical picture helps avoid treating the wrong underlying problem.

Why Doesn't the Same IC Treatment Work for Everyone?

If you've tried an IC/BPS treatment that worked for someone else but didn't help you, it doesn't necessarily mean you did anything wrong.

It may simply mean your symptoms involve different contributing mechanisms.

For example:

These aren't rigid treatment rules.

Some therapies may benefit multiple phenotypes, and many people require a combination of approaches.

Research suggests that identifying symptom patterns can help clinicians select more relevant treatments, although phenotype-based care is still evolving and doesn't guarantee a particular outcome.¹˒³

The key is understanding that IC/BPS treatment should be guided by the individual rather than the diagnosis alone.

What If You Haven't Found a Treatment That Works?

Living with persistent bladder or pelvic pain can be frustrating, particularly when you've tried several approaches without meaningful improvement.

But an unsuccessful treatment doesn't necessarily mean your symptoms can't improve.

It may be worth discussing whether your current treatment plan addresses all the factors contributing to your symptoms.

For example, someone receiving bladder-directed treatment may also benefit from an assessment of pelvic floor muscle function.

Someone with widespread pain and fatigue may need additional support for overlapping chronic pain conditions.

And someone with persistent, severe bladder symptoms may require further evaluation for Hunner lesions or other causes.

Treatment should also be reassessed when symptoms change or when the response isn't what you and your healthcare provider expected.

You don't need to identify your phenotype on your own.

A healthcare provider familiar with IC/BPS can help determine which features are most relevant and whether additional assessment or referral is appropriate.

The Bottom Line

Not all interstitial cystitis is the same.

Although people with IC/BPS may share symptoms such as bladder pain, urinary urgency, and frequency, the factors contributing to those symptoms can vary considerably.

Some people have primarily bladder-focused symptoms.

Others have identifiable Hunner lesions, widespread pain, pelvic floor muscle dysfunction, or a combination of these features.

Recognizing these differences may help explain why a treatment that works for one person doesn't necessarily work for another.

And while researchers are still refining how IC/BPS phenotypes are defined and treated, one message is becoming increasingly clear.

The most effective approach to IC/BPS care is often one that considers the whole person, not just the bladder.

Understanding your symptom pattern can be an important first step toward finding a treatment plan that better reflects your individual needs.

References

1. Wolff GF, et al. Interstitial cystitis/bladder pain syndrome patient phenotyping. Neurourol Urodyn. Published online June 25, 2025. doi:10.1002/nau.70098

2. Clemens JQ, Erickson DR, Varela NP, Lai HH. Diagnosis and treatment of interstitial cystitis/bladder pain syndrome. J Urol. 2022;208(1):34-42. doi:10.1097/JU.0000000000002756

3. Interstitial cystitis/bladder pain syndrome: matching therapies to the patient. Curr Bladder Dysfunct Rep. 2025.

4. Definition change and update of clinical guidelines for interstitial cystitis and bladder pain syndrome. 2024.

5. Validation of distinct bladder pain phenotypes utilizing the MAPP Research Network cohort. 2024.

6. FitzGerald MP, Anderson RU, Potts J, et al. Randomized multicenter clinical trial of myofascial physical therapy in women with interstitial cystitis/painful bladder syndrome. J Urol. 2012;187(6):2113-2118. doi:10.1016/j.juro.2012.01.123