To evaluate the prevalence rates for constipation and faecal and urinary incontinence in children attending primary care clinics in the United States.Retrospective review of case records of all children, 4-17 years of age, seen for at least one health maintenance visit during a 6 month period and followed from birth or within the first 6 months of age in our clinics. We reviewed all charts for constipation, faecal incontinence and urinary incontinence.We included 482 children in the study, after excluding 39 children with chronic diseases. The prevalence rate for constipation was 22.6% and was similar in boys and girls. The constipation was functional in 18% and acute in 4.6%. The prevalence rate for faecal incontinence (> or =1/week) was 4.4%. The faecal incontinence was associated with constipation in 95% of our children. The prevalence rate for urinary incontinence was 10.5%; 3.3% for daytime only, 1.8% for daytime with night-time and 5.4% for night-time urinary incontinence. Faecal and urinary incontinence were significantly more commonly observed in children with constipation than in children without constipation.The prevalence rates were 22.6% for constipation, 4.4% for faecal incontinence and 10.5% for urinary incontinence in a US primary care clinic. Children with constipation had higher prevalence rates for faecal and urinary incontinence than children without constipation. Boys with constipation had higher rates of faecal incontinence than girls with constipation.