The aim of this study is to investigate the importance of clinical characterization of children with monosymptomatic nocturnal enuresis (MNE) in order to improve treatment efficacy.

The hypothesis is that clinical characterization by measurement of nocturnal urine production and maximal voided volumes in children with MNE and subsequent treatment tailoring improves the response to first-line treatment approach.

This is a randomized, controlled study.

This study will be performed at Aarhus University Hospital (Denmark), Ghent University Hospital (Belgium) and Hospital of Zhengzhou University (China) following the same protocol.

According to the initial randomization, children will be allocated to treatment without (group A) or with (group B) prior clinical characterization based on home recordings.

Group A: The children will be randomized to either an enuresis alarm or desmopressin without evaluating the home recordings.

Group B: The home recordings will be evaluated and treatment will be based on the recordings. Desmopressin will be administered to the children with nocturnal polyuria and the conditional alarm to the children with reduced bladder capacity. Children with nocturnal polyuria and reduced bladder capacity will be treated with both desmopressin and conditional alarm. Children with neither nocturnal polyuria nor reduced bladder capacity will again be randomized to either desmopressin or alarm treatment.

Inclusion Criteria:

• Age 6-14 years.
• Three or more wet nights per week regarding the home registrations.

Exclusion Criteria:

• Ongoing constipation and/or faecal incontinence.
• Daytime symptoms such as urgency, frequency or incontinence.
• Recurrent urinary tract infections.
• Anamnestic, clinical or laboratory findings that can be related to diseases or conditions that might affect the parameters investigated.
• Neurological and/or known clinically significant anatomical abnormalities of the urinary tract.
• Former operations in the urinary tract.
• Prior or ongoing treatment with alarm, desmopressin or anticholinergics.
• Ongoing medication that may interfere with the parameters tested.
• Pregnant or lactating girl.
• Contra-indications for the use of desmopressin: habitual or psychogenic polydipsia, use of diuretics, renal insufficiency, hyponatremia or SIADH.
• Hypersensitivity / allergy to substances in the tablets.

The children and the parents will not know, if there treatment is based on home recordings or not.