Urinary incontinence is defined as the involuntary release of urine occurring two or more times per month after toilet training has been completed. Incontinence may be present
During the day (daytime or diurnal incontinence)
At night (nighttime incontinence, enuresis, or bed-wetting)
Both (combined incontinence)
The duration of the process of toilet training, or the age at which children achieve urinary continence, varies greatly. However, more than 90% of children achieve daytime urinary continence by age 5. Nighttime continence may take longer to achieve.
Bed-wetting or nighttime incontinence affects about 30% of children at age 4, 10% at age 7, 3% at age 12, and 1% at age 18. About 0.5% of adults continue to have nighttime incontinence. Doctors take these timelines into account when diagnosing urinary incontinence. Because the duration of the process of toilet training varies, young children are usually not considered to have daytime incontinence if they are under age 5 or 6 or nighttime incontinence if they are under age 7.
Daytime incontinence is more common among girls. Bed-wetting is more common among boys and among children who have a family history of it. Both daytime and nighttime incontinence are symptoms—not diagnoses—and doctors look for an underlying cause.
A person's urination (voiding) pattern matures and transitions from the one that occurs during infancy to the one that occurs during adulthood. In the infant pattern, bladder contractions occur by reflex, and the urine is not stopped by contraction of the urinary sphincter (muscles around the tube that drains urine from the bladder). In the adult pattern, bladder contractions are suppressed by signals from the brain.
Causes of Urinary Incontinence in Children
The pattern of incontinence helps the doctor determine the likely cause. If the child has never had a consistent dry period during the day, the doctor may consider the possibility of a birth defect, an anatomic abnormality, or certain behaviors that can lead to incontinence.
Several uncommon but important disorders affect the normal anatomy or function of the bladder, which can lead to urinary incontinence. For example, a spinal cord defect such as spina bifida can cause abnormal nerve function to the bladder and lead to incontinence. Some infants have a birth defect that prevents the bladder or urethra from developing completely, leading to nearly constant urine loss (total incontinence). Another type of birth defect causes the tubes that connect the kidneys to the bladder (ureters) to end in an abnormal location in the bladder or even outside the bladder (such as in the vagina or urethra or on the surface of the body), causing incontinence (see Misplaced ureters). Some children have an overactive bladder that easily spasms or contracts, causing incontinence, whereas others may have difficulty emptying their bladder.
Certain behaviors can lead to daytime incontinence, especially in girls. Such behaviors include urinating infrequently and urinating using an incorrect position (with legs too close together). With such positions, urine can accumulate in the vagina during urination, then dribble out after standing. Some girls have bladder spasms when laughing, resulting in “giggle incontinence.”
If the child has been dry for a long time and the incontinence is new, the doctor considers conditions that can cause loss of continence. These include constipation, infections, diet, emotional stress, and sexual abuse. Some medical conditions that the child develops can cause new urinary incontinence.
Constipation, which is defined as difficult, hard, or infrequent stooling, is the most common cause of sudden changes in urinary continence in children.
Bacterial urinary tract infections (UTIs) and viral infections causing bladder irritation (bacterial or viral cystitis) are common infectious causes.
To prevent urine from leaking, many children with incontinence learn to cross their legs or use other positions (holding maneuvers), such as squatting (sometimes with their hand or heel pressed between their legs). These holding maneuvers may increase the chance of developing a urinary tract infection.
Sexually active adolescents can have urinary difficulties caused by certain sexually transmitted infections.
Dietary causes include caffeine and acidic juices, such as orange and tomato juice, which can irritate the bladder and lead to leakage of urine.
Stressful events such as divorce or separation of the parents, moving, or loss of a family member can cause a child to develop urinary incontinence (usually temporarily).
Children who are sexually abused may develop urinary incontinence.
Children with diabetes mellitus, argininevasopressin deficiency (central diabetes insipidus), or nephrogenic diabetes insipidus can develop incontinence because these disorders produce excessive amounts of urine.
Common causes of urinary incontinence
Causes of urinary incontinence vary depending on whether incontinence occurs in the daytime or mainly at night.
In nighttime incontinence (enuresis, or bed-wetting), most cases do not involve a medical disorder but result from a combination of factors, including
Developmental delay
Uncompleted toilet training
A bladder that contracts before it is completely full
Drinking too much before bedtime
Problems waking up from sleep (for example, being a very deep sleeper)
Family history (if one parent had nighttime incontinence, there is a 30% chance offspring will have it, increasing to 70% if both parents had it)
About 30% of cases are caused by an underlying medical disorder. Contributing factors include some of the disorders that cause daytime incontinence along with disorders that increase the amount of urine. Such disorders include diabetes mellitus, argininevasopressin deficiency (central diabetes insipidus), nephrogenic diabetes insipidus, and sickle cell disease (and sometimes sickle cell trait).
For daytime incontinence, common causes include
A bladder that is irritated because of a urinary tract infection or because something is pressing on it (such as a full rectum caused by constipation)
An overactive bladder
Urethrovaginal reflux (also called vaginal voiding), which can occur in girls who urinate in an incorrect position or who have extra skin folds, and can cause urine to back up into the vagina and then leak out when they stand up
Anatomic abnormalities (often caused by birth defects, for example, a misplaced ureter in girls or a congenital urinary tract obstruction)
Weakness of the urinary sphincter, which controls the flow of urine out of the bladder (for example, because of a spinal cord abnormality)
A bladder that does not empty completely (neurogenic bladder) because of a spinal cord or nervous system defect
In both types of incontinence, stress, attention-deficit/hyperactivity, or urinary tract infection can increase the risk of incontinence.
Evaluation of Urinary Incontinence in Children
Doctors first try to determine whether incontinence is simply a developmental issue or whether a disorder is involved.
Warning signs
In children with urinary incontinence, certain signs and characteristics are cause for concern. They include
Signs or concerns of sexual abuse
Excessive thirst, excessive volume of urine, and/or weight loss
Incontinence during the day in children 6 years of age or older
Any signs of nerve damage, especially in the legs
Signs of an abnormality of the spine
Newly developed incontinence in children who have been dry for over 1 year
Signs of nerve damage in the legs include weakness in, or difficulty moving, one or both legs and complaints that the legs "feel funny."
Signs of an abnormality of the spine include a deep pit or dimple or an unusual patch of hair in the middle of the lower back.
When to see a doctor
Children who have any warning sign should immediately be brought to a doctor with experience in treating children unless the only warning sign is daytime incontinence in children who are 6 years of age or older. Such children should see a doctor at some point, but a delay of a week or so is not harmful.
What the doctor does
Doctors first ask questions about the child's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause of the incontinence and the tests that may need to be done (see table Some Causes and Features of Nighttime Incontinence in Children and table Some Causes and Features of Daytime Incontinence in Children).
In the medical history, doctors ask about when symptoms began, timing of symptoms, and whether symptoms are continuous (that is, constant dribbling) or intermittent. Having the parents record the timing, frequency, and volume of urine (a voiding diary) and the frequency, size, and consistency of stool (a stooling diary) in a journal can be helpful. Position while urinating and strength of urine stream are discussed.
Some symptoms that suggest a cause include
Decreased frequency of stools and/or hard or unusually large stools (constipation)
Fever, abdominal pain, pain while urinating, and increased urgency to pass urine (urinary tract infection)
Itching around the anus, rectum, or vagina (pinworm infection)
Urinating frequently and producing a large volume of urine (argininevasopressin deficiency [central diabetes insipidus], nephrogenic diabetes insipidus, or diabetes mellitus)
Snoring or breathing pauses during sleep and being excessively sleepy during the day (sleep apnea)
Doctors also ask about any history of birth injuries or birth defects (such as spina bifida), nerve disorders, kidney disorders, and urinary tract infections.
Doctors screen the child for the possibility of sexual abuse, which, although an uncommon cause, is too important to miss.
If there is a family history of bed-wetting or any urologic disorders, these should be brought to the doctors' attention. Doctors also ask questions about any stressors occurring near the start of symptoms, including difficulties at school, with friends, or at home (including questions about parents' marital difficulties). Although incontinence is not a psychologic disorder, a brief period of wetting may occur during times of psychologic stress.
Doctors ask whether children feel weakness of the legs when running or standing.
Doctors then do a physical examination. Examination begins with the following:
A review of vital signs for fever (may indicate a urinary tract infection), weight loss and excessive thirst (may indicate diabetes), and hypertension (may indicate a kidney disorder)
Examination of the head and neck for enlarged tonsils, mouth breathing, or poor growth (may indicate sleep apnea)
Examination of the abdomen for any masses that suggest stool is being retained or for a full bladder
Examination of the genitals in girls for any adhesions (when the lips of the vagina stick together), scarring, or signs suggesting sexual abuse
Examination of the genitals in boys for any irritation or lesions on the penis or around the anus or rectum
Examination of the spine for any defects (for example, a tuft of hair or a dimple at the base of the spine)
A neurologic examination to evaluate leg strength, sensation, deep tendon reflexes, and other reflexes (such as lightly touching the anus to see whether it constricts—called the anal wink—and, in boys, lightly stroking the inner thigh to see whether the testis is pulled up—called the cremasteric reflex)
A rectal examination may be done during the physical examination to detect constipation or decreased rectal tone
Testing
Often doctors can diagnose the cause by the history, physical examination, a urinalysis, and a urine culture. Doctors may do other tests depending on what they find during their evaluation (see table Some Causes and Features of Nighttime Incontinence in Children and table Some Causes and Features of Daytime Incontinence in Children). For example, to help diagnose diabetes mellitus and diabetes insipidus, doctors do blood and urine tests to check sugar and electrolyte levels. To diagnose urinary tract infection, doctors do a urinalysis and urine culture.
If a birth defect is suspected, an ultrasound examination of the kidneys and bladder and x-rays of the spine may be necessary. Ultrasonography also can be used to determine the size of the rectum. An x-ray of the abdomen may done to confirm the presence of a large amount of stool.
A special x-ray of the bladder and kidneys, called a voiding cystourethrogram, may also be needed. With this test, a dye is injected into the bladder using a catheter, which shows the anatomy of the urinary tract as well as the direction of urine flow.
Treatment of Urinary Incontinence in Children
Learning about the cause and course of incontinence helps decrease the negative psychologic impact of urine accidents. Doctors ask how the child is being impacted by the incontinence because that could affect the treatment decisions.
Treatment of incontinence depends on the cause of the incontinence. For example, an infection is usually treated with antibiotics. Children with birth defects or anatomic abnormalities may need surgery.
Successful treatment of urinary incontinence also depends on parent and child participation in the treatment plan. If the child is immature, not bothered by the wetting, or unwilling to participate in the treatment plan, the plan should be postponed until the child is ready to participate.
Other measures can be taken depending on whether incontinence is at night or during the day.
Nighttime incontinence (enuresis, or bed-wetting)
Doctors typically tell parents to begin with behavioral modifications for their child. Modifications include the following:
Limiting how much the child drinks in the evening—80% of daily liquids should be consumed before 5 PM
Limiting liquids 2 hours before sleep
Urinating 2 times consecutively before sleep (called double-voiding)
Managing constipation appropriately
The most effective long-term strategy is a bed-wetting alarm. Although labor intensive, the success rate can be as high as 70% when children are motivated to end the bed-wetting, and the family is able to follow the plan. It can take up to 4 months of nightly use for symptoms to completely resolve. Parents should not punish children for bed-wetting. Punishment only undermines treatment and causes poor self-esteem.
Each year, enuresis tends to resolve without treatment in about 15% of affected children as they grow.
Imipramine is now rarely given because it may rarely cause sudden death.
Daytime incontinence
General measures may include
Trying urgency containment exercises (to strengthen the urinary sphincter)
Gradually lengthening the time between visits to the bathroom (if the child is thought to have a weak bladder muscle or dysfunctional voiding)
Changing behavior (for example, delaying urination) through positive reinforcement and scheduled urination
Reminding children to urinate by a clock that vibrates or sounds an alarm (this is preferable to having a parent in the reminder role)
Using methods that discourage retention of urine in the vagina (for example, sitting facing backward on the toilet or with the knees wide apart)
Teaching children how to exercise and control the pelvic floor muscles (the uterus, vagina, bladder, urethra, and rectum) and abdomen muscles to promote coordinated urination (using biofeedback)
Urgency containment exercises involve telling children to go to the bathroom as soon as they feel the urge to urinate. But once in the bathroom, they are asked to hold the urine as long as they can. When they can hold it no longer they should start to urinate but then stop and start urinating every few seconds. This exercise strengthens the urinary sphincter and also gives children confidence that they can make it to the bathroom before they have an accident. This exercise should be taught after the child has been evaluated by a doctor.
Girls who have adhesions are given a cream that contains estrogen.
Key Points
Understanding why the child is incontinent is essential to the child's outcome and well-being.
Most often, incontinence is not caused by a medical disorder.
Treatment includes behavioral changes, dietary changes to manage constipation, and sometimes medications.
Alarms are the most effective treatment for bed-wetting.
Most nighttime enuresis (bed-wetting) improves as the child matures.
