The term enuresis is used to describe involuntary urination. Bed wetting is called nocturnal enuresis. Inability to control bladder function during the day is called diurnal enuresis. Most children get control of daytime urination by 2 years and nighttime urination by 3 – 4 years.


Primary Nocturnal Enuresis

Primary nocturnal enuresis is where the child has never managed to be consistently dry at night.

The most common cause of primary nocturnal enuresis is a variation on normal development, particularly if the child is younger than 5 years. Often patients will have a family history of delayed dry nights. In this situation reassurance is important, and there is no need to jump to further investigations or management.

Other causes of primary nocturnal enuresis include:

  • Overactive bladder. Frequent small volume urination prevents the development of bladder capacity.
  • Fluid intake prior to bedtime, particularly fizzy drinks, juice and caffeine, which can have a diuretic effect
  • Failure to wake due to particularly deep sleep and underdeveloped bladder signals
  • Psychological distress, for example low self esteem, too much pressure or stress at home or school
  • Secondary causes such as chronic constipation, urinary tract infection, learning disability or cerebral palsy

The initial step in management of primary nocturnal enuresis is to establish the underlying cause. It can be helpful to keep a 2 week diary of toileting, fluid intake and bedwetting episodes. This helps establish any patterns and identifies areas that may be changed, such as fluid intake before bed. It is important to take a history and examination to exclude underlying physical or psychological causes.

Management of primary nocturnal enuresis involves:

  • Reassure parents of children under 5 years that it is likely to resolve without any treatment
  • Lifestyle changes: reduced fluid intake in the evenings, pass urine before bed and ensure easy access to a toilet
  • Encouragement and positive reinforcement. Avoid blame or shame. Punishment should very much be avoided.
  • Treat any underlying causes or exacerbating factors, such as constipation
  • Enuresis alarms
  • Pharmacological treatment


Secondary Nocturnal Enuresis

Secondary nocturnal enuresis is where a child begins wetting the bed when they have previously been dry for at least 6 months. This is more indicative of an underlying illness than primary enuresis. Causes of secondary nocturnal enuresis include:

  • Urinary tract infection
  • Constipation
  • Type 1 diabetes
  • New psychosocial problems (e.g. stress in family or school life)
  • Maltreatment

Always think about abuse and safeguarding, particularly with deliberate bedwetting, punishment for bedwetting (despite parental education) or unexplained secondary nocturnal enuresis.

Management of secondary nocturnal enuresis is based on treating the underlying cause. The most common and easily treatable secondary causes are urinary tract infections and constipation. Other problems may require referral to secondary care for further management.


Diurnal Enuresis

Diurnal enuresis is daytime incontinence. This occurs when the person has become dry at night but still has episodes of urinary incontinence during the day. This occurs more frequently in girls. Incontinence comes in two main types:

  • Urge incontinence is an overactive bladder that gives little warning before emptying
  • Stress incontinence describes leakage of urine during physical exertion, coughing or laughing.

Other causes of diurnal enuresis include

  • Recurrent urinary tract infections
  • Psychosocial problems
  • Constipation


Enuresis Alarms

An enuresis alarm is a device that makes a noise at the first sign of bed wetting, waking the child and stopping them from urinating. It requires quite a high level of training and commitment and needs to be used consistently for a prolonged period (i.e. at least 3 months). Some families may find them very helpful, whereas others may find they add to the burden and frustration and are counter productive.


Pharmacological Treatment

Medication for nocturnal enuresis is usually initiated by a specialist.

Desmopressin is an analogue of vasopressin (also known as anti-diuretic hormone). It reduces the volume of urine produced by the kidneys. It is taken at bedtime with the intention of reducing nocturnal enuresis.

Oxybutinin is an anticholinergic medication that reduces the contractility of the bladder. It can be helpful where there is an overactive bladder causing urge incontinence.

Imipramine is a tricyclic antidepressant. It is not clear how it works, but it may relax the bladder and lighten sleep.


Last updated August 2019