The Effect of Melatonin on Nocturnal Enuresis

Inclusion Criteria: * Monosymptomatic nocturnal enuresis * Age 6-14 years * Clinical examination normal * ≥ 3 wet nights / week due to either nocturnal polyuria with normal bladder size or reduced functional bladder capacity with normal urine output Exclusion Criteria: * Constipation (by ROME III criteria) * Day incontinence * Overactive bladder (ICCS 2008 classification of symptoms) * Current or past history of clinical or laboratory findings that can be related to diseases or - conditions (eg pregnancy) likely to change the parameters examined, especially diseases of the kidney and urinary tract, liver or endocrine disorder. * Clinical signs of urinary tract infection * Hypertension, blood pressure assessed by ambulatory measurement with blood pressure cuff * Set treatment with one or more drugs