Nighttime enuresis, or bedwetting, is usually defined as the involuntary loss of urine during sleep after the age of 5 years. It's known to cluster in family groups — if one or both parents have had trouble with bedwetting, their children are more likely to have similar problems. Bedwetting is also more common in boys.
Fifteen percent of 5-year-olds and 10 percent of 6-year-olds experience enuresis. As children mature, the number of children with enuresis problems declines at a rate of about 15 percent per year.
The cause of bedwetting is not known. Twenty to 30 years ago, psychological problems were thought to be the cause, but this is no longer believed to be the case in the overwhelming majority of children. And contrary to popular belief, research has shown that children with nighttime enuresis do not have abnormal sleep patterns.
There are several theories, but most doctors think the difficulty lies with a developmental delay in the bladder. Just as some children walk and talk before others their age, bladder control may have wide variations, and these children simply need more time for their bladders to fully develop. The delayed development theory is supported by the fact that, for most children, bedwetting problems spontaneously disappear as they get older.
In some children, inadequate production of a hormone that decreases urine output during sleep may be the cause. This hormone, called antidiuretic hormone (ADH), occurs naturally in all of us and is responsible for concentrating urine if we become dehydrated. Secretion of this hormone is normally high at night.
It's unlikely that a physical cause is behind your child's bedwetting if your child:
- Is wet only during sleep
- Has never had a urinary tract infection
- Urinates normally during the day
A physical cause might be the culprit if your child:
- Is wet day and night
- Gets urinary tract infections
- Has trouble with bowel control
If your child is wet during the day and night, it's important to rule out other causes of wetness, such as voiding dysfunction, infection, dysfunctional elimination syndrome and birth defects. For these children, a voiding diary, X-rays and lab tests may be recommended to determine if there's any underlying problem.
The treatment for bedwetting may consist of medication, conditioning and behavior modification, or a combination of approaches. Since bedwetting is very common until 6 years of age, we generally don't try to treat it earlier. At any age, decisions regarding treatment should consider to what extent the problem affects the child and the child's social development. Many young children and their parents are better served by reassurance that there's no physical abnormality than by long-term and expensive therapy of uncertain effectiveness.
Your child's doctor can do a nighttime enuresis evaluation. During the visit, the doctor will ask about parental or sibling bedwetting, previous urinary tract problems, establishment of toilet training and daytime control.
The physical exam will include careful examination of the abdomen and genitalia, and a neurologic exam of the legs and perineum to determine sensation and adequate motor development. The lower back is inspected to check for abnormalities that might suggest abnormal development of the spinal cord.
If your child has a completely normal medical history and physical examination, and a normal urine test, further testing isn't needed.
Treating bedwetting isn't an exact science. Since it's very common until 6 years of age, we generally don't try to treat it earlier. At any age, decisions regarding treatment should consider to what extent the problem affects the child and the child's social development. Many young children and their parents are better served by reassurance that there's no physical abnormality than by long-term and expensive therapy of uncertain effectiveness.
Treatment may consist of medication, conditioning and behavior modification, or a combination of approaches.
There's no medication that cures enuresis — they only treat symptoms. When the drug is stopped, the enuresis will usually return unless the child has naturally outgrown it. Two commonly used drugs are Tofranil (imipramine) and DDAVP (desmopressin acetate).
Tofranil (imipramine) was the first drug introduced to treat bedwetting but we don't know exactly how it works. We do know that it relaxes the bladder muscle, and that it may lighten sleep. The drug benefits the child only on the night taken but doesn't cure the condition.
- Is generally used in children older than 6 years
- Has a success rate of 10 to 50 percent
- Starts working in a few days
- Is relatively inexpensive
- Will likely stop working when the child stops taking the medication
Imipramine is available in capsule or tablet form only. The dosage for children age 7 to 8 is 25 mg, given one hour before bedtime. Dosage for kids age 9 years and older is 50 mg to 75 mg, given one hour before bedtime.
Side effects of Tofranil include:
- Loss of appetite
- Overdosage can cause cardiac irregularities and convulsions
Because taking too much could cause cardiac irregularities and convulsions, an adult should administer the imipramine to the child personally and keep the drug out of children's reach. The prescribed dose won't cause cardiac irregularities.
Due to this medication's side effects, risks with overdosage and limited success rate, we prescribe it infrequently. We typically use Tofranil only with adolescents who don't respond to all other treatments.
DDAVP (desmopressin acetate) mimics the natural hormone that causes the kidneys to conserve body water and concentrate the urine, decreasing urine output during sleep.
- Significantly improves bedwetting in 25 to 65 percent of children; 12 to 40 percent of kids achieve complete dryness
- Is generally recommended in children older than 6 years
- Can be used as needed for overnight trips once the correct dosage has been established
Side effects are minimal, if any. However, the drug is expensive and about 80 percent of children who stop taking it will relapse. The optimal duration of treatment is unknown.
The dosage is one 0.2 mg tablet at bedtime for one week. If your child becomes dry, continue at this dose. If your child remains wet, increase the dose to two 0.2 mg tablets for one week. If your child becomes dry, stay at this dosage. If your child remains wet, increase the dose to three 0.2 mg tablets for one week. If your child becomes dry, continue at this dose. If not, discontinue the medication and call our office.
If the medication works, use it for three to six months and then gradually taper the dose over several weeks.
DDAVP is safe and often effective, but it's important to use it only at bedtime to reduce the risk of fluid overload and electrolyte abnormalities. It is a drug that's nice to have available for sleepovers, camp, vacations and the like. However, it is expensive and is not a cure.
Conditioning and Behavior Modification
Although many approaches to treating enuresis have included behavioral modification, by far the most effective have been "conditioning" alarm units. The alarm unit is designed to awaken the child when he or she begins to wet. The small units are self-contained and the child wears it on the shoulder or the wrist. The unit is activated by a small electrode sewn or attached directly onto the child's underclothing. At present, there are three kinds of alarm units on the market: One emits sound when it senses that the child has urinated, one vibrates, and one can do both. The traditional alarm emits sound.
This method is inexpensive but quite labor intensive, requiring patience. The major cause of failure is poor compliance on the part of the child and the parents. It must be emphasized that this is truly family therapy and the parents must be willing to accept the responsibility of supervising the therapy. When rigidly adhered to, as many as 80 percent of children will ultimately show improved nighttime urinary control, although it may take six to eight months.
The principle of conditioning therapy is that repetitively arousing the child at the time of the wetting episode can ultimately condition the child to recognize that urination is about to happen, and teach the child to inhibit the voiding reflex. Therefore, it's essential during the first few weeks for the parents to wake the child completely when the alarm goes off.
The major problems with the alarm units are the length of time it takes to get an adequate result, the disruption of the entire family's sleep and the fact that many children react sluggishly to the alarm.
As many as 35 percent of children may relapse several months after the family stops using the alarm, but children can be easily retreated in a short period of time. Other techniques may help to reduce relapse. These might include increasing fluids during the day and continued use of the moisture alarm once the child is staying dry at night.
Methods often tried by parents before they seek medical attention, such as limiting fluids before bedtime, awakening the child at night at random and reward-punishment strategies, are generally ineffective. Treatment of enuresis can be lengthy and frustrating. Success is in no way assured. But ultimately, all children with simple enuresis will outgrow this pattern eventually.
Our Approach to Treating Bedwetting
Our approach to treating enuresis is to first start a trial of DDAVP. This gives the child a treatment option that ensures dryness during times when bedwetting would be particularly inconvenient or traumatic. After a trial of DDAVP, we generally recommend that the parents consider a subsequent trial of a behavior-conditioning program. The intermittent use of DDAVP along with a conditioning retraining is often effective in increasing self-confidence while working toward a cure that isn't drug-dependent.
UCSF Benioff Children's Hospitals medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your child's doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your child's provider.
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