Urinary Incontinence
in Children
In the United States, at
least 13 million people have problems holding urine until they can get
to a toilet. This loss of urinary control is called "urinary incontinence"
or just "incontinence." Although it affects many young people,
it usually disappears naturally over time, which suggests that incontinence,
for some people, may be a normal part of growing up. No matter when
it happens or how often it happens, incontinence causes great distress.
It may get in the way of a good night's sleep and is embarrassing when
it happens during the day. That's why it is important to understand
that occasional incontinence is a normal part of growing up and that
treatment is available for most children who have difficulty controlling
their bladders.
How Does the Urinary System Work? Urination, or voiding, is a complex
activity. The bladder is a balloonlike muscle that lies in the lowest
part of the abdomen. The bladder stores urine, then releases it through
the urethra, the canal that carries urine to the outside of the body.
Controlling this activity involves nerves, muscles, the spinal cord,
and the brain.
The bladder is made of
two types of muscles: the detrusor, a muscular sac that stores urine
and squeezes to empty, and the sphincter, a circular group of muscles
at the bottom or neck of the bladder that automatically stay contracted
to hold the urine in and automatically relax when the detrusor contracts
to let the urine into the urethra. A third group of muscles below the
bladder (pelvic floor muscles) can contract to keep urine back.
A baby's bladder fills
to a set point, then automatically contracts and empties. As the child
gets older, the nervous system develops. The child's brain begins to
get messages from the filling bladder and begins to send messages to
the bladder to keep it from automatically emptying until the child decides
it is the time and place to void.
Failures in this control
mechanism result in incontinence. Reasons for this failure range from
the simple to the complex.
Incontinence happens less
often after age 5: About 10 percent of 5-year-olds, 5 percent of 10-year-olds,
and 1 percent of 18-year-olds experience episodes of incontinence. It
is twice as common in boys as in girls.
What Causes Nighttime Incontinence? After age 5, wetting at night--often
called bedwetting or sleepwetting--is more common than daytime wetting
in boys. Experts do not know what causes nighttime incontinence. Young
people who experience nighttime wetting tend to be physically and emotionally
normal. Most cases probably result from a mix of factors including slower
physical development, an overproduction of urine at night, a lack of
ability to recognize bladder filling when asleep, and, in some cases,
anxiety. For many, there is a strong family history of bedwetting, suggesting
an inherited factor.
Slower Physical Development
Between the ages of 5 and
10, incontinence may be the result of a small bladder capacity, long
sleeping periods, and underdevelopment of the body's alarms that signal
a full or emptying bladder. This form of incontinence will fade away
as the bladder grows and the natural alarms become operational.
Excessive Output of Urine
During Sleep
Normally, the body produces
a hormone that can slow the making of urine. This hormone is called
antidiuretic hormone, or ADH. The body normally produces more ADH at
night so that the need to urinate is lower. If the body doesn't produce
enough ADH at night, the making of urine may not be slowed down, leading
to bladder overfilling. If a child does not sense the bladder filling
and awaken to urinate, then wetting will occur.
Anxiety
Experts suggest that anxiety-causing
events occurring in the lives of children ages 2 to 4 might lead to
incontinence before the child achieves total bladder control. Anxiety
experienced after age 4 might lead to wetting after the child has been
dry for a period of 6 months or more. Such events include angry parents,
unfamiliar social situations, and overwhelming family events such as
the birth of a brother or sister.
Incontinence itself is
an anxiety-causing event. Strong bladder contractions leading to leakage
in the daytime can cause embarrassment and anxiety that lead to wetting
at night.
Genetics
Certain inherited genes
appear to contribute to incontinence. In 1995, Danish researchers announced
they had found a site on human chromosome 13 that is responsible, at
least in part, for nighttime wetting. If both parents were bedwetters,
a child has an 80 percent chance of being a bedwetter also. Experts
believe that other, undetermined genes also may be involved in incontinence.
Obstructive Sleep Apnea
Nighttime incontinence
may be one sign of another condition called obstructive sleep apnea,
in which the child's breathing is interrupted during sleep, often because
of inflamed or enlarged tonsils or adenoids. Other symptoms of this
condition include snoring, mouth breathing, frequent ear and sinus infections,
sore throat, choking, and daytime drowsiness. In some cases, successful
treatment of this breathing disorder may also resolve the associated
nighttime incontinence.
Structural Problems
Finally, a small number
of cases of incontinence are caused by physical problems in the urinary
system in children. Rarely, a blocked bladder or urethra may cause the
bladder to overfill and leak. Nerve damage associated with the birth
defect spina bifida can cause incontinence. In these cases, the incontinence
can appear as a constant dribbling of urine.
What Causes Daytime Incontinence? Daytime incontinence that is not associated
with urinary infection or anatomic abnormalities is less common than
nighttime incontinence and tends to disappear much earlier than the
nighttime versions. One possible cause of daytime incontinence is an
overactive bladder. Many children with daytime incontinence have abnormal
voiding habits, the most common being infrequent voiding.
An Overactive Bladder
Muscles surrounding the
urethra (the tube that takes urine away from the bladder) have the job
of keeping the passage closed, preventing urine from passing out of
the body. If the bladder contracts strongly and without warning, the
muscles surrounding the urethra may not be able to keep urine from passing.
This often happens as a consequence of urinary tract infection and is
more common in girls.
Infrequent Voiding
Infrequent voiding refers
to a child's voluntarily holding urine for prolonged intervals. For
example, a child may not want to use the toilets at school or may not
want to interrupt enjoyable activities, so he or she ignores the body's
signal of a full bladder. In these cases, the bladder can overfill and
leak urine. Additionally, these children often develop urinary tract
infections (UTIs), leading to an irritable or overactive bladder.
Other Causes
Some of the same factors
that contribute to nighttime incontinence may act together with infrequent
voiding to produce daytime incontinence. These factors include
a small bladder capacity
structural problems
anxiety-causing events
pressure from a hard bowel movement (constipation)
drinks or foods that contain caffeine, which increases urine output
and may also cause spasms of the bladder muscle, or other ingredients
to which the child may have an allergic reaction, such as chocolate
or artificial coloring
Sometimes overly strenuous toilet training may make the child unable
to relax the sphincter and the pelvic floor to completely empty the
bladder. Retaining urine (incomplete emptying) sets the stage for urinary
tract infections.
What Treats or Cures Incontinence?
Growth and Development
Most urinary incontinence
fades away naturally. Here are examples of what can happen over time:
Bladder capacity increases.
Natural body alarms become
activated.
An overactive bladder settles
down.
Production of ADH becomes
normal.
The child learns to respond to the body's signal that it is time to
void.
Stressful events or periods pass.
Many children overcome incontinence naturally (without treatment) as
they grow older. The number of cases of incontinence goes down by 15
percent for each year after the age of 5.
Medications
Nighttime incontinence
may be treated by increasing ADH levels. The hormone can be boosted
by a synthetic version known as desmopressin, or DDAVP, which recently
became available in pill form. Patients can also spray a mist containing
desmopressin into their nostrils. Desmopressin is approved for use by
children.
Another medication, called
imipramine, is also used to treat sleepwetting. It acts on both the
brain and the urinary bladder. Unfortunately, total dryness with either
of the medications available is achieved in only about 20 percent of
patients.
If a young person experiences
incontinence resulting from an overactive bladder, a doctor might prescribe
a medicine that helps to calm the bladder muscle. This medicine controls
muscle spasms and belongs to a class of medications called anticholinergics.
Bladder Training and Related
Strategies
Bladder training consists
of exercises for strengthening and coordinating muscles of the bladder
and urethra, and may help the control of urination. These techniques
teach the child to anticipate the need to urinate and prevent urination
when away from a toilet. Techniques that may help nighttime incontinence
include
determining bladder capacity
stretching the bladder (delaying urinating)
drinking less fluid before sleeping
developing routines for waking up
Unfortunately, none of
the above has demonstrated proven success.
Techniques that may help
daytime incontinence include
urinating on a schedule,
such as every 2 hours (this is called timed voiding)
avoiding caffeine or other foods or drinks that you suspect may contribute
to your child's incontinence
following suggestions for healthy urination, such as relaxing muscles
and taking your time
Moisture Alarms
At night, moisture alarms
can awaken a person when he or she begins to urinate. These devices
include a water-sensitive pad worn in pajamas, a wire connecting to
a battery-driven control, and an alarm that sounds when moisture is
first detected. For the alarm to be effective, the child must awaken
or be awakened as soon as the alarm goes off. This may require having
another person sleep in the same room to awaken the bedwetter.
Incontinence is also called
enuresis
Primary enuresis refers
to wetting in a person who has never been dry for at least 6 months.
Secondary enuresis refers to wetting that begins after at least 6 months
of dryness.
Nocturnal enuresis refers to wetting that usually occurs during sleep
(nighttime incontinence).
Diurnal enuresis refers to wetting when awake (daytime incontinence).
Points to Remember Urinary incontinence in children is common.
Nighttime wetting occurs more commonly in boys.
Daytime wetting is more common in girls.
After age 5, incontinence disappears naturally at a rate of 15 percent
of cases per year.
Treatments include waiting, dietary modification, moisture alarms, medications,
and bladder training.
