Functional daytime incontinence: definitions and epidemiology.

The definition of childhood urinary incontinence, used here, is leakage of at least 1 ml of urine at least once a week in a child from 5 years of age. Functional day wetting is incontinence not caused by disease, injury or congenital malformation, and is almost always urge incontinence due to an unstable bladder. The following figures for prevalence are quoted from the Gothenburg study of 35567-year-old school entrants. Any kind of urinary incontinence at least once a week was reported by 6% of the children. Day wetting at least once a week was found in 3.1% of the girls and 2.1% of the boys. Most of the day wetting children also had urgency which was reported in 82% of the girls and 74% of the boys. Bedwetting at least once a week was reported by 2.9% of the girls and 3.8% of the boys. The bedwetting was monosymptomatic (no additional symptoms, no day wetting) in 39% of the girls and 59% of the boys with nocturnal enuresis. Combined daytime and night-time incontinence was reported by 17% of the children, while 22% wet only by day, and 61% only by night. None of the 3556 children had a previously undetected organic cause for their incontinence. There is a strong association between bacteriuria and day wetting in girls, but not in boys. We do not know whether the bacteria cause the disturbance of bladder function, or vice versa. The cause and effect may work in both directions.