Introduction

Enuresis in children often occurs at night, with or without daytime features.

It can be divided into primary (has always had enuresis) and secondary (was continent, and later developed incontinence due to a secondary cause).

  • Common reversible causes: UTI, constipation, emotional stress.
  • Diagnosis requires a full voiding and bowel history with examination to exclude neurological disorders.
  • Treatment with oxybutynin, fluid restriction, bladder training and behavioural therapies may be effective
  • In secondary enuresis, treating the underlying cause will typically resolve the problem
  • Enuresis before the age of 5 is normal, and is only considered pathological after the age of 5

In about 1% of cases it persists into adulthood. Cases in older children and younger adults can be particularly emotionally distressing.

Aetiology

  • More common in boys
  • The frequency of the bedwetting determines the severity. More frequent cases typically take longer to resolve
  • Often a family history
  • Associated with sleep apnoea (30% of cases)
  • More common on obese children – affects 30% of obese children
  • Associated with global developmental delay
  • Factors that contribute to secondary enuresis
    • Emotional stress – e.g. bullying, separation from mother, starting new school
    • Constipation (+/- anal fissure)
    • UTI

Pathology

Nocturnal enuresis is defined as wetting the bed after the age of 5.
At first, all children will wet the bed at night. This is normal, and occurs when the child has not yet learned to manually control their sphincter. Girls usually manage to achieve this before boys; most girls stay dry by about age 6, while in boys it is age 7. By age 10, 95% of children stay dry at night.
Bed wetting depends on two things:
Vasopressin (ADH) ‚Äď normal cyclical patterns of this hormones secretion mean that higher levels are secreted at night, and so there is less urine produced at night. When you are born, the cyclical secretion of this has not yet developed- and in some people it does not develop properly (perhaps less than 10% of enuresis patients ‚Äď and hereditary factors may be involved). You can take a nasal spray of this hormone before bed to prevent bed wetting ‚Äď however prolonged use of this is not recommended.
Ability to recognise when bladder is full- this is another mechanism that develops as the child grows, and it is independent of the vasopressin mechanism.
At age 5, 20% of children will bed wet.
At age 10, 5%
At age 15, 2%
Even after the age of 18, up to 1% of people will wet the bed.
There are two main types of enuresis:
  1. Primary nocturnal enuresis (PNE)‚Äď this is where the child has never experienced a period of prolonged dryness and continues to wet the bed more than 2 nights a week after the age of 5.
    • May be a disorder of sleep arousal – whereby the child is not awakened by the sensation of a full bladder
    • May be due to an overactive bladder or small bladder volume
    • It can be further divided into:
      1. Those with daytime symptoms
      2. Those without daytime symptoms
  2. Secondary nocturnal enuresis(SNE) ‚Äď this occurs after the child has had a period of at least 6 months without bed wetting. It can be related to emotional stress, constipation (+/- anal fissure) and UTI.
As well as the causes discussed above, up to 10% of children who bed wet may have a defect of the urinary tract that causes their problems.

Clinical features and history

Primary enuresis

  • How many times a week?
  • At what time does bedwetting occur?
    • Is there a pattern?
  • Does the child wake after the wetting
  • What is the daytime toilet use pattern?
    • If there are daytime symptoms – consider screening for UTI
  • Any constipation?
  • Fluid intake
  • Any other developmental problems?
  • Why have they presented at this particular time?
    • School trip
    • Sleepover
    • Family troubled by the problem

Secondary enuresis

  • When did it start?
  • Does this correlate with any other changes in the child’s life?
  • Bedwetting pattern
    • How often?
    • How may nights per week
    • Any pattern?
    • Does the child wake after bedwetting

Examination

  • Abdominal examination
    • May elicit an enlarged bladder (outflow obstruction), or a mass consistent with faecal loading (constipation)
  • Spine – spina bifida
  • Lower limb neurological examination – neurological cause
  • Perineum
  • Urine dipstick (UTI, diabetes)

Diagnosis

Ask the parents to keep a diary of:

  • Times of enuresis (both daytime and night time)
  • Time of bowels opening
  • Bristol stool scale of the bowel motion

Indications for further investigation

  • Primary enuresis with ¬†daytime symptoms
    • Urine MC+S
    • Assessment of constipation
  • Secondary enuresis
    • Urine MC+S
    • Assessment of constipation
    • Blood sugar for diabetes
    • Behaviours / emotional issues
    • Consider child abuse
    • Ask the child if they think it is a problem and what the cause is

Treatment

Most cases are managed in primary care.

Primary enuresis often suits a more conservative approach and tends to settle with time, whilst secondary enuresis is consider to be more serious, and and thorough history, examination and potentially investigations should be performed to seek an underlying diagnosis.

Educate parents about behavioural strategies to help bedwetting

  • Reassure the parents it is a common problem and most children will grow out of it
  • Encourage regular fluids throughout the day and before bed –¬†don’t¬†advise withholding of fluids
    • Avoid caffeinated drinks before bed
  • Encourage regular toilet breaks throughout the day – e.g. during school break times, and at night before going to bed
  • Avoid lifting or carrying the child to the toilet during the night – wake them up and encourage them to be independent
  • Consider a¬†dry bed training¬†regimen
    • Night 1: The child is woken every hour until 1am and encouraged to go to the bathroom
    • Nights 2-6: The child is woken once, 3 hours after falling asleep, and encouraged to go to the toiler
    • Night 7: The child should wake on their own
    • Repeat if >3 consecutive nights of bed wetting

Primary enuresis

  • Waiting ‚Äď many parents get anxious when their child wets the bed, but often they will outgrow it if you give them long enough. Some research shows that punishing a child for bed wetting can make the situation worse, as the punishments results in lower self-esteem and a downward spiral of symptoms.
  • Alarm ‚Äď a moisture detecting pad can be placed in the bed, and an alarm goes off when it gets wet. This wakes up the child, and helps them to associate the feeling of a full bladder, with having to wake up. These alarms make children 13x more likely to stop bed wetting, however there is a high relapse rate (up to 50%) and treatment regimens often have to be repeated.
    • Suitable for well motivated children from the age of 6-7 onwards
    • The child should be “in charge” of the alarm – they should learn how to turn it off – and should be fully awake when getting up to go to the toilet when it goes off!
    • Typically takes about 6-8 weeks to work
    • Needs an emotionally supportive family. Often not useful in an emotionally distressed household.
    • Efficacy may be assisted by the use of positive reinforcement – such as a start chart. These should be used to reinforce the behaviours of getting up and going to the toilet, operating the alarm correctly – and¬†not¬†for dry nights alone
    • Typically available for hire from pharmacies or community health providers. Can also be purchased outright for about GBP¬£50 or AUD$100.
    • Discontinue if no benefit within 4 weeks
    • Once dry for >2 weeks – encourage fluid intake before bed time to reinforce the sensation and behaviour of getting up to go to the bathroom. This is sometimes called¬†overlearning
    • Involving the child in the cleaning of the soiled bedsheets has been proven to make alarm therapy more effective
Enuresis alarm

Enuresis alarm. This file is taken from wikimedia commons and is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

  • Desmopressin
    • Available as a sublingual “melt” or a tablet
      • sublingual – 120-240mcg at night
      • Oral – 200-400mcg at night
      • Age 6+ only
      • Risk of hyponatraemia (low), but avoid concurrent use of NSIADs
    • Indicated if alarm therapy is not appropriate or has failed
    • High relapse rate – 60-70%
    • May be suitable for short-term use (e.g. for school trips and sleepovers)
    • Restrict fluid from one hour before dose until 8 hours after dose
    • Cease after 4 weeks if ineffective
    • Cease one week every 3 months to assess ongoing need for medication
  • Studies have shown that alarm training is either slightly more effective or equally effective to desmopressin, but that desmopressin treatment has a higher relapse rate
  • Tricyclics¬†are no longer recommended – very high relapse rate, and inferior to alarms and desmopressin
  • Oxybutynin¬†may be used in cases with severe daytime symptoms. It is not effective (nor indicated) for nocturnal enuresis alone

Secondary Enuresis

  • Treat any underlying constipation
    • High fibre diet
    • Osmotic laxative – such as movicol (dose depends on child’s age)
    • Encourage regular fluid intake
  • Otherwise, the same measures as above – include:
    • Alarms
    • Behavioural therapies
    • Desmopressin

Indications for referral to paediatrics

  • Persistent symptoms despite use of an alarm
  • Day-time enuresis when secondary causes have been ruled out
  • History of recurrent UTI
  • Diabetes or developmental delay has been idnetified
  • Significant emotional or psychosocial problems

Faecal incontinence

  • Most commonly due to constipation in children with psychological predisposing factors.
  • History and examination is required to rule out physical cause e.g. coeliac disease and Hirschsprung‚Äôs disease.
  • Management involves explaining the physiology of the condition (remove blame from child); treatment of constipation (stimulant laxative); behavioural strategies (toilet-sitting times).
  • 5 year cure is 75%

References

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