What Is Interstitial Cystitis?
Interstitial cystitis (IC), one of the chronic pelvic pain disorders, is a condition resulting in recurring discomfort or pain in the bladder and the surrounding pelvic region. The symptoms of IC 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 surrounding pelvic area. Symptoms may include an urgent need to urinate (urgency), frequent need to urinate (frequency), 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.
In IC, the bladder wall may be irritated and become scarred or stiff. Glomerulations (pinpoint bleeding caused by recurrent irritation) may appear on the bladder wall. Some people with IC find that their bladders 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. People with severe cases of IC may urinate as many as 60 times a day.
Also, people with IC often experience pain during sexual intercourse. IC is far more common in women than in men. Of the more than 700,000 Americans estimated to have IC, 90 percent are women.
What Causes IC?
Some of the symptoms of IC resemble those of bacterial infection, but medical tests reveal no organisms in the urine of patients with IC. Furthermore, patients with IC do not respond to antibiotic therapy. Researchers are working to understand the causes of IC and to find effective treatments.
One theory being studied is that IC is an autoimmune response following a bladder infection. Another theory is that a bacterium may be present in bladder cells but not detectable through routine urine tests. Some scientists have suggested that certain substances in urine may be irritating to people with IC, but no substance unique to people with IC has as yet been isolated. 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. No gene has yet been implicated as a cause.
Are There Different Types of IC?
Because IC varies so much in symptoms and severity, most researchers believe that it is not one, but several, diseases. In the past, cases were mainly categorized as ulcerative IC or nonulcerative IC, based on whether ulcers had formed on the bladder wall. But many researchers and clinicians have questioned the usefulness of this classification, since the vast majority of cases do not involve ulcers, and their presence or absence does not influence treatment options as much as other factors do.
Factors that influence treatment options include whether bladder capacity under anesthesia is great or small, and whether mast cells are present in the tissue of the bladder wall, which may be a sign of an allergic or autoimmune reaction. In some cases, the success or failure of a treatment helps characterize the type of IC. For example, some cases respond to changes in diet while others do not.
How Is IC Diagnosed?
Because symptoms are similar to those of other disorders of the urinary system and because there is no definitive test to identify IC, doctors must rule out other conditions before considering a diagnosis of IC. Among these disorders are urinary tract or vaginal infections, bladder cancer, bladder inflammation or infection caused by radiation to the pelvic area, eosinophilic and tuberculous cystitis, kidney stones, endometriosis, neurological disorders, sexually transmitted diseases, low-count bacteria in the urine, and, in men, chronic bacterial and nonbacterial prostatitis.
The diagnosis of IC in the general population is based on
Diagnostic tests that help identify other conditions include urinalysis, urine culture, cystoscopy, biopsy of the bladder wall, distention of the bladder under anesthesia, urine cytology, and, in men, laboratory examination of prostate secretions.
Urinalysis and Urine Culture
Culture of Prostate Secretions
Cystoscopy Under Anesthesia with Bladder Distention
The doctor may also test the patient's maximum bladder capacity--the maximum amount of liquid or gas the bladder can hold. This must be done under anesthesia since the bladder capacity is limited by either pain or a severe urge to urinate. A small bladder capacity under anesthesia helps support the diagnosis of IC.
Future Diagnostic Tools
As researchers learn more about the causes of IC, more accurate and less invasive diagnostic procedures are likely to emerge. For example, some researchers are studying the possibility that urine samples from people with IC contain substances not found in normal urine. If an IC marker in the urine can be found, patients may not have to undergo a cystoscopic examination or biopsy to receive a diagnosis.
What Are the Treatments for IC?
Scientists have not yet found a cure for IC, nor can they predict who will respond best to which treatment. Symptoms may disappear without explanation or coincide with an event such as a change in diet or treatment. Even when symptoms disappear, they may return after days, weeks, months, or years. Scientists do not know why.
Because the causes of IC are unknown, current treatments are aimed at relieving symptoms. Most people are helped for variable periods by one or a combination of treatments. As researchers learn more about IC, the list of potential treatments will change, so patients should discuss their options with a doctor.
Researchers are not sure why distention helps, but some believe that it may increase capacity and interfere with pain signals transmitted by nerves in the bladder. Symptoms may temporarily worsen 24 to 48 hours after distention, but should return to predistention levels or improve after 2 to 4 weeks.
The only drug approved by the U.S. Food and Drug Administration (FDA) for bladder instillation is dimethyl sulfoxide (DMSO, RIMSO-50). DMSO treatment involves guiding a narrow tube called a catheter up the urethra into the bladder. A measured amount of DMSO is passed through the catheter into the bladder, where it is retained for about 15 minutes before being expelled. Treatments are given every week or two for 6 to 8 weeks and repeated as needed. Most people who respond to DMSO notice improvement 3 or 4 weeks after the first 6- to 8-week cycle of treatments. Highly motivated patients who are willing to catheterize themselves may, after consultation with their doctor, be able to have DMSO treatments at home. Self-administration is less expensive and more convenient than going to the doctor's office.
Doctors think DMSO works in several ways. Because it passes into the bladder wall, it may reach tissue more effectively to reduce inflammation and block pain. It may also prevent muscle contractions that cause pain, frequency, and urgency.
A bothersome but relatively insignificant side effect of DMSO treatments is a garlic-like taste and odor on the breath and skin that may last up to 72 hours after treatment. Long-term treatment has caused cataracts in animal studies, but this side effect has not appeared in humans. Blood tests, including a complete blood count and kidney and liver function tests, should be done about every 6 months.
The FDA-recommended dosage of Elmiron is 100 mg, three times a day. Patients may not feel relief from IC pain for the first 2 to 4 months. A decrease in urinary frequency may take up to 6 months. Patients are urged to continue with therapy for at least 6 months to give it an adequate chance to relieve symptoms.
Elmiron's side effects are limited primarily to minor gastrointestinal discomfort. A small minority of patients experienced some hair loss, but hair grew back when they stopped taking the drug. Researchers have found no negative interactions between Elmiron and other medications.
Elmiron may affect liver function, which should therefore be monitored by the doctor.
Because Elmiron has not been tested in pregnant women, the manufacturer recommends that it not be used during pregnancy, except in the most severe cases.
Other Oral Medications
Some patients have experienced improvement in their urinary symptoms by taking antidepressants or antihistamines. Antidepressants help reduce pain and may also help patients deal with the psychological stress that accompanies living with chronic pain. In patients with severe pain, narcotic analgesics such as Tylenol with codeine or longer acting narcotics may be necessary.
All drugs--even those sold over the counter--have side effects. Patients should always consult a doctor before using any drug for an extended time.
Transcutaneous Electrical Nerve Stimulation
TENS is relatively inexpensive and allows the patient to take an active part in treatment. Within some guidelines, the patient decides when, how long, and at what intensity TENS will be used. It has been most helpful in relieving pain and decreasing frequency in patients with Hunner's ulcers. Smokers do not respond as well as nonsmokers. If TENS is going to help, improvement is usually apparent in 3 to 4 months.
Those considering surgery should discuss the potential risks and benefits, side effects, and long- and short-term complications with a surgeon and with their family, as well as with people who have already had the procedure. Surgery requires anesthesia, hospitalization, and weeks or months of recovery, and as the complexity of the procedure increases, so do the chances for complications and failure.
To locate a surgeon experienced in performing specific procedures, check with your doctor.
Two procedures--fulguration and resection of ulcers--can be done with instruments inserted through the urethra. Fulguration involves burning Hunner's ulcers with electricity or a laser. When the area heals, the dead tissue and the ulcer fall off, leaving new, healthy tissue behind. Resection involves cutting around and removing the ulcers. Both treatments are done under anesthesia and use special instruments inserted into the bladder through a cystoscope. Laser surgery in the urinary tract should be reserved for patients with Hunner's ulcers and should be done only by doctors who have had special training and have the expertise needed to perform the procedure.
Another surgical treatment is augmentation, which makes the bladder larger. In most procedures, scarred, ulcerated, and inflamed sections of the patient's bladder are removed, leaving only the base of the bladder and healthy tissue. A piece of the patient's bowel (large intestine) is then removed, reshaped, and attached to what remains of the bladder. After the incisions heal, the patient may void less frequently. The effect on pain varies greatly; IC can sometimes recur on the segment of bowel used to enlarge the bladder.
Even in carefully selected patients--those with small, contracted bladders--pain, frequency, and urgency may remain or return after surgery, and the patient may have additional problems with infections in the new bladder and difficulty absorbing nutrients from the shortened intestine. Some patients are incontinent, while others cannot void at all and must insert a catheter into the urethra to empty the bladder.
Bladder removal, called a cystectomy, is another surgical option. Once the bladder has been removed, different methods can be used to reroute urine. In most cases, ureters are attached to a piece of bowel that opens onto the skin of the abdomen; this procedure is called a urostomy, and the opening is called a stoma. Urine empties through the stoma into a bag outside the body. Some urologists are using a second technique that also requires a stoma but allows urine to be stored in a pouch inside the abdomen. At intervals throughout the day, the patient puts a catheter into the stoma and empties the pouch. Patients with either type of urostomy must be very careful to keep the area in and around the stoma clean to prevent infection. Serious potential complications may include kidney infection and small bowel obstruction.
A third method to reroute urine involves making a new bladder from a piece of the patient's bowel and attaching it to the urethra. After healing, the patient may be able to empty the newly formed bladder by voiding at scheduled times or by inserting a catheter into the urethra. Few surgeons have the special training and expertise needed to perform this procedure.
Even after total bladder removal, some patients still experience variable IC symptoms in the form of phantom pain. Therefore, the decision to undergo a cystectomy should be undertaken only after testing all alternative methods and after seriously considering the potential outcome.
A surgical variation of TENS, called saccral nerve root stimulation, involves permanent implantation of electrodes and a unit emitting continuous electrical pulses. Studies of this experimental procedure are now under way.
Are There Any Special Concerns?
There is no evidence that IC increases the risk of bladder cancer.
Is Any Research Being Done?
Although answers may seem slow in coming, researchers are working hard to solve the painful riddle of IC. Some scientists receive funds from the Federal Government to help support their research, while others receive support from their employing institution, drug companies, or patient support associations.
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), a part of the National Institutes of Health (NIH), leads the Federal Government's research efforts on IC. Most studies funded by NIDDK result from unsolicited grant applications sent to NIH by scientists at universities and medical centers throughout the United States. Other NIDDK-funded studies result from solicitations issued to encourage increased research on a particular topic.
By law, all applications sent to NIH are first reviewed by non-Government experts in the field of the proposed research for scientific merit and feasibility before being reviewed by NIDDK's National Advisory Council. This council is made up of non-Government scientists, health professionals, and people who represent voluntary groups interested in the Institute's research. Approved applications are eligible for funding based on a rating of scientific merit, or priority score, assigned by the initial reviewers. Applications are usually funded in order of priority score; the best applications are funded first.
Largely because of special solicitations, NIDDK's investment in scientifically meritorious IC research across the country has grown considerably since 1987. The Institute now supports research that is looking at various aspects of IC, such as how the components of urine may injure the bladder and what possible role organisms identified by nonstandard methods may have in causing IC. In addition to funding research, NIDDK sponsors scientific workshops where investigators share the results of their studies and discuss future areas for investigation.
Clinical Trials Group
The second trial will test whether the bacterium Bacillus Calmette-Guérin (BCG) will relieve the pelvic pain and frequent urination that are hallmarks of IC. Participants will be randomly assigned to have either a BCG or saline solution temporarily placed in the bladder during each of six clinic visits. Neither doctors nor patients will know who received the BCG until the study ends. Patients whose symptoms are not relieved by the initial series will be openly offered BCG.
The materials listed below may be found in medical libraries, in many college and university libraries, through interlibrary loan in most public libraries, and at bookstores. Items are listed for information only; inclusion does not imply endorsement by NIH.
Articles and Book Chapters
Hanno, P. (1998). Interstitial cystitis and related diseases. In P. C. Walsh, A. B. Retik, E. D. Vaughan, & A. J. Wein (Eds.), Campbell's urology (7th ed., pp. 631-662). Philadelphia, PA: W. B. Saunders Company.
Wein, A., & Hanno, P. (Eds.). (1997). Interstitial cystitis: An update of the current information. Urology, 49 (5A, Suppl.).
Books and Booklets
Sant, G. (Ed.). (1997). Interstitial cystitis. Philadelphia, PA: Lippincott-Raven.
American Foundation for Urologic Disease
American Pain Society
American Urogynecologic Society
Interstitial Cystitis Association
International Association for the Study of Pain
National Chronic Pain Outreach Association
National Kidney Foundation
National Organization of Social Security Claimants' Representatives
Social Security Administration
United Ostomy Association
The U.S. Government does not endorse or favor any specific commercial product or company. Trade, proprietary, or company names appearing in this document are used only because they are considered necessary in the context of the information provided. If a product is not mentioned, this does not mean or imply that the product is unsatisfactory.
National Kidney and Urologic Diseases Information Clearinghouse
3 Information Way
The National Kidney and Urologic Diseases Information Clearinghouse (NKUDIC) is a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The NIDDK is part of the National Institutes of Health under the U.S. Department of Health and Human Services. Established in 1987, the clearinghouse provides information about diseases of the kidneys and urologic system to people with kidney and urologic disorders and to their families, health care professionals, and the public. NKUDIC answers inquiries, develops and distributes publications, and works closely with professional and patient organizations and Government agencies to coordinate resources about kidney and urologic diseases.
Publications produced by the clearinghouse are carefully reviewed by both NIDDK scientists and outside experts.
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NIH Publication No. 02-3220