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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 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
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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.
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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
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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
Pinpoint bleeding on the bladder
- presence of urgency, frequency, or pelvic/bladder pain
- cystoscopic evidence (under anesthesia) of bladder wall
inflammation, including Hunner's ulcers or glomerulations (present
in 90 percent of patients with IC)
- absence of other diseases that could cause the
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.
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These tests can detect and identify the most common organisms
that infect the urine and that may cause symptoms similar to IC.
However, organisms such as Chlamydia cannot be detected with
these tests, so a negative culture does not rule out all types of
infection. 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.
In men, the doctor might obtain prostatic fluid and examine it
for signs of an infection, which can then be treated with
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 will also distend or stretch the bladder to its capacity
by filling it with a liquid or gas. Because bladder distention is
painful in patients with IC, they must be given some form of
anesthesia for the procedure. These tests can detect bladder wall
inflammation; a thick, stiff bladder wall; and Hunner's ulcers.
Glomerulations are usually seen only after the bladder has been
stretched to capacity.
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.
A biopsy is a tissue sample that is then examined under a
microscope. Samples of the bladder and urethra may be removed during
a cystoscopy and later examined with a microscope. A biopsy helps
rule out bladder cancer.
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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
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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.
Because many patients have noted an improvement in symptoms after
a bladder distention has been done to diagnose IC, the procedure is
often thought of as one of the first treatment attempts.
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.
During a bladder instillation, also called a bladder wash or
bath, the bladder is filled with a solution that is held for varying
periods of time, averaging 10 to 15 minutes, before being
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
Pentosan polysulfate sodium (Elmiron)
This first oral drug developed for IC was approved by the FDA in
1996. In clinical trials, the drug improved symptoms in 38 percent
of patients treated. Doctors do not know exactly how it works, but
one theory is that it may repair defects that might have developed
in the lining of the bladder.
The FDA-recommended oral 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 the drug 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
Aspirin and ibuprofen are easy to obtain and may be a first line
of defense against mild discomfort. Doctors may recommend other
drugs to relieve pain.
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
acetaminophen (Tylenol) with codeine or longer acting narcotics may
All drugs--even those sold over the counter--have side effects.
Patients should always consult a doctor before using any drug for an
With transcutaneous electrical nerve stimulation (TENS), mild
electric pulses enter the body for minutes to hours two or more
times a day either through wires placed on the lower back or just
above the pubic area, between the navel and the pubic hair, or
through special devices inserted into the vagina in women or into
the rectum in men. Although scientists do not know exactly how TENS
relieves IC pain, it has been suggested that the electrical pulses
may increase blood flow to the bladder, strengthen pelvic muscles
that help control the bladder, or trigger the release of substances
that block pain.
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.
There is no scientific evidence linking diet to IC, but many
doctors and patients find that alcohol, tomatoes, spices, chocolate,
caffeinated and citrus beverages, and high-acid foods may contribute
to bladder irritation and inflammation. Some patients also note that
their symptoms worsen after eating or drinking products containing
artificial sweeteners. Patients may try eliminating various items
from their diet and reintroducing them one at a time to determine
which, if any, affect their symptoms. It is important, however, to
maintain a varied, well-balanced diet.
Many patients feel that smoking makes their symptoms worse.
Because smoking is the major known cause of bladder cancer, one of
the best things smokers can do for their bladder is to quit.
Many patients feel that gentle stretching exercises help relieve
People who have found adequate relief from pain may be able to
reduce frequency by using bladder training techniques. Methods vary,
but basically patients decide to void (empty their bladder) at
designated times and use relaxation techniques and distractions to
keep to the schedule. Gradually, patients try to lengthen the time
between scheduled voids. A diary in which to record voiding times is
usually helpful in keeping track of progress.
Many approaches and techniques are used, each of which has its
own advantages and complications that should be discussed with a
surgeon. Surgery should be considered only if all available
treatments have failed and the pain is disabling. Most doctors are
reluctant to operate because the outcome is unpredictable--some
people still have symptoms after surgery.
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 for 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 of these 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 colon (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 colon 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 colon. Some patients are incontinent, while
others cannot void at all and must insert a catheter into the
urethra to empty the bladder.
A surgical variation of TENS, called sacral nerve root
stimulation, involves permanent implantation of electrodes and a
unit emitting continuous electrical pulses. Studies of this
experimental procedure are now under way.
Bladder removal, called a cystectomy, is another surgical
option. Once the bladder has been removed, different methods can be
used to reroute the urine. In most cases, ureters are attached to a
piece of colon 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 colon 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. Only a 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 made only after testing
all alternative methods and after seriously considering the
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There is no evidence that IC increases the risk of bladder
Researchers have little information on pregnancy and IC but
believe that the disorder does not affect fertility or the health of
the fetus. Some women find that their IC goes into remission during
pregnancy, while others experience a worsening of their
The emotional support of family, friends, and other people with IC is very
important in helping patients cope. Studies have found that patients who learn
about the disorder and become involved in their own care do better than patients
who do not.
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Although answers may seem slow in coming, researchers are working
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.
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 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.
An important part of NIDDK's IC research program has been the
National IC Database Study, the first systematic, long-term look at
a large number of people with IC. Baseline data have been analyzed
to provide a foundation for subsequent studies in the IC Clinical
In 1998, NIDDK initiated the IC Clinical Trials Group, a project
designed to develop and test new treatment strategies for patients
with IC. The first trial is testing two oral drugs. One group is
being treated with Elmiron, a second with Atarax, a third with both
drugs, and a fourth with placebo.
The second trial is testing whether the bacterium Bacillus
Calmette-Guérin (BCG) relieves the pelvic pain and frequent
urination that are hallmarks of IC. Participants are randomly
assigned to have either a BCG or a saline solution temporarily
placed in the bladder during each of six clinic visits. Neither
doctors nor patients know who has received the BCG until the study
ends. Patients whose symptoms are not relieved by the initial series
will be openly offered BCG.
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American Foundation for Urologic
American Pain Society
American Urogynecologic Society
for the Study of Pain
Cystitis Associationof America
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