Urinary incontinence in children: suggestions for definitions and terminology.

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. The types of incontinence are defined as detrusor incontinence (daytime urge incontinence and night-time enuresis), sphincter incontinence (presenting clinically as stress incontinence in the less serious form, as continuous dribbling of urine in the more serious one), and combined incontinence (the combination of detrusor hyperactivity and sphincter incompetence found in many children with neurogenic bladder dysfunction). Urinary incontinence in children is subdivided into night-time (most common) and daytime incontinence. Day wetting is aetiologically subdivided into incontinence due to organic or functional causes. The organic causes can be either structural (e.g. epispadias) or neurogenic. Functional day wetting is incontinence not caused by disease, injury or congenital malformation, and is almost always urge incontinence due to an unstable bladder. Unstable bladder in children may activate the sphincteric guarding reflex, leading to dyscoordination between the sphincter and the detrusor, and, eventually, overdistension of the bladder with a reduced contraction power of the detrusor ('lazy bladder'). Ultimately, Hinman's syndrome (non-neurogenic neurogenic bladder) may develop. The term enuresis should be used to denote incontinent, complete micturitions and should thus be reserved for bedwetting and giggle enuresis.