• The most common cause of bed-wetting is a slowly maturing bladder.
• Limiting fluids 2 to 3 hours before bed and restricting caffeine consumption may help prevent bed-wetting.
• Positive reinforcement, bed-wetting alarms, desmopressin, and imipramine help treat the disorder.

About 30% of children still wet the bed at age 4, 10% at age 6, 3% at age 12, and 1% at age 18. Bed-wetting is more common among boys and seems to run in families.

Bed-wetting is usually caused by slow maturation of the nerves that supply the bladder, so the child does not awaken appropriately when the bladder fills and needs emptying. Bed-wetting can accompany such sleep disorders as sleepwalking and night terrors (see Behavioral and Developmental Problems in Young Children: Sleep Problems in Children). A physical disorder—usually a urinary tract infection—is found in only 1 to 2% of children who wet the bed. Other less common disorders, such as diabetes, also can cause bed-wetting. Bed-wetting occasionally is caused by psychologic problems, either in the child or in another family member, and is occasionally part of a constellation of symptoms that suggests the possibility of sexual abuse.

Sometimes bed-wetting stops and then begins again. The relapse usually follows a psychologically stressful event or condition, but a physical cause, especially a urinary tract infection, may be responsible.

Treatment

Parents and the child need to know that bed-wetting is quite common, that it can be corrected, and that nobody should feel guilty about it. An older child who wets the bed can take responsibility by

• Talking to a doctor
• Limiting fluids after dinner (especially caffeinated beverages)
• Urinating before going to bed
• Recording wet and dry nights
• Changing clothing and bedding when wet

Parents may choose to give the child age-appropriate rewards (positive reinforcement) for dry nights.

For children younger than 6, parents can avoid giving the child fluids 2 to 3 hours before bedtime and encourage the child to urinate just before going to bed. Caffeinated beverages should be strictly limited. In most children of this age, time and physical maturation solve the problem.

For children older than 6 to 7 years, some form of treatment is often indicated. Bed-wetting alarms, which awaken a child when a few drops of urine are detected, are the most effective treatment available. They can cure bed-wetting in about 70% of children, and only about 10 to 15% of children start wetting the bed again after the alarms are stopped. Alarms are relatively inexpensive and are easy to set up. In the first few weeks of use, the child awakens only after fully urinating. In the next few weeks, the child awakens after urinating a small amount and may wet the bed less often. Eventually, the need to urinate wakes the child before the bed is wet. Most parents find that the alarm can be removed after a 3-week dry period.

If bed-wetting persists in an older child after alarms and age-appropriate rewards have been tried, the doctor may prescribe drugs. An increasingly popular drug for bed-wetting is desmopressin in tablet form or, rarely, nasal spray form. This drug reduces the output of urine, which reduces bed-wetting. The drug is used for a 1- to 2-month period and then is stopped as soon as possible. It can be used intermittently, such as when the child goes to camp. Imipramine is an antidepressant drug used infrequently to treat bed-wetting because it relaxes the bladder and tightens the sphincter that blocks urine flow. It has become less popular in recent years because of side effects. To monitor side effects, doctors do an electrocardiogram before imipramine therapy is started and do blood tests periodically.

Last full review/revision February 2009 by Stephen Brian Sulkes, MD