Robson at the Children’s Clinic, Suite 111,

The parents of an 8-year-old boy bring him to the pediatrician’s office for evaluation of nightly bed-wetting. On half the nights, his urine soaks through a pair of absor-bent disposable underpants into the sheets. He often does not void during school hours, and when he returns home after school, he usually rushes to the bathroom. He arrives home thirsty after school, and the majority of his daily fluid intake is in the 5 hours from 3:30 p.m. to bedtime. His physical examination is normal, apart from hard stool palpated in the left lower quadrant. In the office he voids 170 ml of urine and has urgency at this volume (average functional capacity for his age, 300 ml). How should this boy be evaluated and treated? The Clinic a l Problem Bed-wetting is common.1,2 According to a recent large, longitudinal study, at least 20% of children in the first grade occasionally wet the bed, and 4 % wet the bed two or more times a week.1 Enuresis is more common in boys than in girls. In a study of 10,960 children in the United States, the prevalence of enuresis in boys at the ages of 7 and 10 years was 9 % and 7%, respectively, and in girls at those ages, 6 % and 3%