[Development of intestinal and bladder control from birth until the 18th year of age. Longitudial study].

The development of bowel and bladder control from 0 to 18 years of age in 321 Swiss children of the Zurich Longitudinal Study (1955-1976) is described. 3% of the children had started toilet training by the age of 1 month and 96% by 12 months. Bowel control was completed in 32% at age one, in 75% at age two and in 97% at age three. Complete bladder control by day and at night was established in none of the children at age one, in 20% at ages two and three and in 90% at age five. About one quarter of the boys and one tenth of the girls had a period of incomplete bowel or bladder control between 6 and 18 years. During the prepubertal period, the annual incidence of enuresis was 7-15% in boys and 7-10% in girls, and that of encopresis 2-4% and 1-2% respectively. Some combination of enuresis diurna, enuresis nocturna and encopresis were found in 7% of all children, although in most children, these events did not occur simultaneously. With the exception of primary diurnal enuresis, the different types of enuresis and encopresis were more frequent in males than in females. By the onset of puberty, encopresis resolved in all children and enuresis persisted in only a few children. The role of toilet training and the etiologies and pathogenesis of enuresis and encopresis are discussed from a development point of view.