Interstitial Cystitis (IC)
Interstitial cystitis (IC) is a condition that results in recurring discomfort or pain in the bladder and the surrounding pelvic region. The symptoms vary from case to case and even in the same individual. People may experience mild discomfort, pressure, tenderness, or intense pain in the bladder and pelvic area. Symptoms may include an urgent need to urinate, a frequent need to urinate, or a combination of these symptoms. Pain may change in intensity as the bladder fills with urine or as it empties. Women's symptoms often get worse during menstruation. They may sometimes experience pain during vaginal intercourse.
Because IC varies so much in symptoms and severity, most researchers believe it is not one, but several diseases. In recent years, scientists have started to use the terms bladder pain syndrome (BPS) or painful bladder syndrome (PBS) to describe cases with painful urinary symptoms that may not meet the strictest definition of IC. The term IC/PBS includes all cases of urinary pain that can't be attributed to other causes, such as infection or urinary stones. The term interstitial cystitis, or IC, is used alone when describing cases that meet all of the IC criteria established by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
In IC/PBS, the bladder wall may be irritated and become scarred or stiff. Glomerulations - pinpoint bleeding - often appear on the bladder wall. Hunner's ulcers - patches of broken skin found on the bladder wall - are present in 10 percent of people with IC.
Some people with IC/PBS find that their bladder cannot hold much urine, which increases the frequency of urination. Frequency, however, is not always specifically related to bladder size; many people with severe frequency have normal bladder capacity when measured under anesthesia or during urologic testing. People with severe cases of IC/PBS may urinate as many as 60 times a day, including frequent nighttime urination, also called nocturia.
IC/PBS is more common in women than in men. An estimated 3.3 million U.S. women, or 2.7 percent, who are 18 years of age or older have pelvic pain and other symptoms, such as urinary urgency or frequency, that are associated with IC/PBS. An estimated 1.6 million U.S. men, or 1.3 percent, who are 30 to 79 years old have persistent symptoms, such as pain with bladder filling or pain relieved by bladder emptying, that are associated with PBS.
What causes IC?
Some of the symptoms of IC/PBS resemble those of bacterial infection, but medical tests reveal no organisms in the urine of people with IC/PBS. Furthermore, people with IC/PBS do not respond to antibiotic therapy. Researchers are working to understand the causes of IC/PBS and to find effective treatments.
Many women with IC/PBS have other conditions such as irritable bowel syndrome and fibromyalgia. Scientists believe IC/PBS may be a bladder manifestation of a more general condition that causes inflammation in various organs and parts of the body.
Researchers are beginning to explore the possibility that heredity may play a part in some forms of IC. In a few cases, IC has affected a mother and a daughter or two sisters, but it does not commonly run in families.
How is IC / PBS diagnosed?
Because symptoms are similar to those of other disorders of the bladder and there is no definitive test to identify IC/PBS, doctors must rule out other treatable conditions before considering a diagnosis of IC/PBS. The most common of these diseases in both sexes are urinary tract infections and bladder cancer. In men, common diseases include chronic prostatitis or chronic pelvic pain syndrome. In women, endometriosis is a common cause of pelvic pain. IC/PBS is not associated with any increased risk of developing cancer.
The diagnosis of IC/PBS in the general population is based on the
- presence of pain related to the bladder, usually accompanied by frequency and urgency of urination
- absence of other diseases that could cause the symptoms
Diagnostic tests that help rule out other diseases include urinalysis, urine culture, cystoscopy, biopsy of the bladder wall and urethra, and distention of the bladder under anesthesia.
Urinalysis and Urine Culture
Examining urine with a microscope and culturing the urine can detect and identify the primary organisms that are known to infect the urinary tract and that may cause symptoms similar to IC/PBS. A urine sample is obtained either by catheterization or by the clean catch method. For a clean catch, the patient washes the genital area before collecting urine midstream in a sterile container. White and red blood cells and bacteria in the urine may indicate an infection of the urinary tract, which can be treated with an antibiotic. If urine is sterile for weeks or months while symptoms persist, the doctor may consider a diagnosis of IC/PBS.
Culture of Prostate Secretions
Although not commonly done, in men without a history of culture-documented urinary tract infections, the doctor might obtain prostatic fluid and examine it for signs of a prostate infection, which can then be treated with antibiotics.
Cystoscopy Under Anesthesia With Bladder Distention
The doctor may perform a cystoscopic examination in order to rule out bladder cancer. During cystoscopy, the doctor uses a cystoscope - an instrument made of a hollow tube about the diameter of a drinking straw with several lenses and a light - to see inside the bladder and urethra. The doctor might also distend or stretch the bladder to its capacity by filling it with a liquid or gas. Because bladder distention is painful for people with IC/PBS, they must be given some form of anesthesia for the procedure.
A biopsy is a tissue sample that can be examined with a microscope. Tissue samples of the bladder and urethra may be removed during a cystoscopy. A biopsy helps rule out bladder cancer.
Future Diagnostic Tools
Researchers are investigating and validating some promising biomarkers such as anti-proliferative factor (APF), some cytokines, and other growth factors. These might provide more reliable diagnostic markers for IC and lead to more focused treatment for the disease.