OVERVIEW

What is the bladder?

The bladder is an organ of the urinary system, commonly referred to as the "urinary sac," primarily used for storing urine in the human body. The bladder is not a sealed organ; it has bilateral ureteral orifices and an internal urethral orifice, connecting to the kidneys and urethra, respectively.

The bladder is mainly composed of epithelial tissue and mesenchymal tissue. The epithelial tissue is like the bricks needed to build a house, while the mesenchymal tissue acts as the adhesive, such as cement, between the bricks.

What is interstitial cystitis?

Interstitial cystitis, also known as Hunner's ulcer, is a chronic bladder inflammation not caused by bacteria. It was first reported in 1915. It is a disease with complex causes, difficult diagnosis, and challenging treatment.

Is interstitial cystitis common? Who is most affected by it?

In the past, this disease was considered rare. However, with advances in medical technology and increased awareness, the number of diagnoses has risen. The condition predominantly affects women, occurring about 10 times more frequently than in men, with the highest incidence among middle-aged individuals aged approximately 30–50.

SYMPTOMS

What are the symptoms of interstitial cystitis?

The common symptoms of interstitial cystitis are similar to those of acute bacterial cystitis, but the onset is sudden and progresses rapidly. Symptoms may occasionally resolve on their own but often recur quickly, making diagnosis challenging and typically requiring exclusion of other conditions. Bladder discomfort worsens as the bladder fills and improves after urination.

The main symptoms can be divided into bladder irritation and pain/discomfort:

• Bladder irritation: Includes urinary frequency, urgency, and pain during urination.

  • Urinary frequency: Increased need to urinate, often with very little urine output each time. While healthy individuals urinate 4–6 times during the day, patients may need to go every few minutes, sometimes passing only a few drops.

  • Urinary urgency: Healthy individuals can delay urination when necessary (e.g., in public), but patients struggle to control the urge and may even experience incontinence.

  • Painful urination: A burning sensation during urination. Among these symptoms, urinary frequency is the most common.

• Pain/discomfort: Pain is typically concentrated in the suprapubic region (where the bladder is located) but may also involve the urethra, vagina, or other areas. The pain is often severe, worsening as the bladder fills and improving after urination.

However, bladder irritation and pain may occur together or separately, but they are not specific to this condition (i.e., they cannot be used alone for diagnosis).

Interstitial cystitis is often associated with other conditions, particularly chronic pain disorders such as vulvodynia, irritable bowel syndrome, and fibromyalgia. Men may experience tenderness in the penis or scrotum.

CAUSES

What are the causes of interstitial cystitis?

The exact cause of interstitial cystitis remains unclear, but it is considered a multifactorial disease. Current mainstream hypotheses regarding its etiology include the following:

• Occult infection: Pathogens (bacteria, viruses) have not yet been identified, but some believe this may be the primary cause.

• Genetic factors: Epidemiological studies show lower incidence rates among Black populations and higher rates in North Americans compared to Japanese, suggesting a possible link to race and heredity.

• Autoimmune factors: Patients often present with other autoimmune diseases, and symptoms improve with immunosuppressive therapy, indicating this may be an autoimmune disorder.

• Others: Damage to the bladder lining (potassium ions), neurogenic inflammatory responses, mast cell activation, etc.

DIAGNOSIS

What tests are needed for interstitial cystitis? What is the significance of these tests for interstitial cystitis?

Routine examinations for urethritis include urinalysis, urine culture + drug sensitivity, urinary system color Doppler ultrasound, cystoscopy, and histopathological examination.

• Urinalysis:

  • A very common test in the diagnosis and treatment of urological diseases. The timing of urine collection varies depending on the purpose of the test. For cystitis, a random, fresh urine sample is usually collected during the visit.
  • The purpose of urinalysis is to determine the presence of white blood cells, red blood cells, protein, and urine pH. In interstitial cystitis, urinalysis is often normal, and this test is mainly used to rule out conditions like bacterial cystitis.

• Urine culture + drug sensitivity:

  • This test usually requires midstream urine collection. Its purpose is to identify the pathogenic bacteria and determine their sensitivity or resistance to antibiotics.
  • However, this test takes longer than urinalysis, sometimes up to 5–7 days, and may fail to culture certain bacteria, such as Mycobacterium tuberculosis.
  • This test has no diagnostic significance for interstitial cystitis but can help identify the bacteria causing bacterial cystitis.

• Urinary system color Doppler ultrasound:

  • A non-invasive and convenient examination. A full bladder is required for clearer imaging. The purpose is to rule out other urinary system diseases, such as stones or tumors.

• Cystoscopy:

  • Similar to gastrointestinal endoscopy, this test is usually performed after imaging studies. It allows direct visualization of the bladder and urethral mucosa, checking for masses. If necessary, tissue samples can be taken for pathological examination. However, it is an invasive procedure and may lead to complications like bleeding or infection. It is not suitable for acute urethritis.
  • Cystoscopy is essential for diagnosing interstitial cystitis and must be performed under anesthesia. The bladder is filled with water to check for bleeding points.

• Histopathological examination: Tissue samples with distinctive features are taken during cystoscopy and sent for pathological analysis, which takes longer. This test is not a specific diagnostic criterion for interstitial cystitis but is used to rule out other bladder conditions, such as tumors or tuberculosis.

Other tests include the potassium sensitivity test and interstitial cystitis biomarker tests, but these are still in the research stage and are not widely available in primary hospitals.

Can interstitial cystitis be diagnosed after completing the above tests?

Diagnosing interstitial cystitis is challenging, as it is an exclusionary disease (meaning other conditions with similar symptoms, such as tumors or tuberculosis, must first be ruled out). Therefore, diagnosis may take a long time.

However, two conditions must be met for a diagnosis of interstitial cystitis: first, symptoms such as frequent urination accompanied by bladder pain; second, cystoscopy under anesthesia (with water distension revealing multiple bleeding points in the bladder, known as Hunter’s ulcers).

TREATMENT

How should interstitial cystitis be treated?

The treatment of interstitial cystitis is challenging and often requires a combination of approaches. Current main treatment methods are divided into non-surgical and surgical options:

• Non-surgical treatment: Focuses on relieving discomfort and improving quality of life. However, not every method works for everyone, and medications should be used under the guidance of a specialist. Common approaches include:

• Oral medications: Antihistamines, antidepressants, calcium channel blockers;

• Bladder distension and bladder instillation, such as dimethyl sulfoxide, heparin, or silver nitrate;

• Surgical treatment: Considered when the condition is severe or non-surgical treatments fail. Common surgical procedures include transurethral resection, bladder augmentation, cystectomy, and bladder denervation.

Should antibiotics be avoided for interstitial cystitis?

Interstitial cystitis is currently considered a non-bacterial inflammation, likely related to autoimmune disorders, so antibiotics are not effective for this condition.

Can interstitial cystitis be completely cured?

Interstitial cystitis is very difficult to treat and rarely cured, but early intervention yields better outcomes.

What complications may arise from interstitial cystitis?

The disease can reduce bladder wall elasticity and impair contraction/relaxation functions. In advanced stages, it may lead to bladder shrinkage (smaller, harder bladder) or even urine reflux into the ureters and kidneys, causing hydronephrosis.

DIET & LIFESTYLE

What should be noted in daily life for interstitial cystitis?

For interstitial cystitis, dietary therapy is also a fundamental treatment approach. It is important to maintain a light diet, minimize the intake of spicy and irritating foods, alcohol, and beverages, and reduce consumption of potassium-rich foods (an electrolyte), such as bananas and tomatoes. Acidic foods like vinegar should also be eaten sparingly. However, while paying attention to diet, it is necessary to prevent malnutrition, so dietary adjustments should be made according to individual circumstances.

PREVENTION

None