OBJECTIVE To evaluate the frequency of urinary incontinence and urinary tract infection in children with chronic constipation and report on the resolution of these with treatment of the underlying constipation. METHODS We evaluated the frequency of urinary incontinence and urinary tract infection in 234 chronic constipated and encopretic children before, and at least 12 months after, the start of treatment for constipation. RESULTS Twenty-nine percent complained of daytime urinary incontinence and 34% of nighttime urinary incontinence. Urinary tract infection was present in 11% and was more commonly present in girls than in boys (33% vs 3%). Vesicoureteral reflux was present in four and megacystis in four of the 25 children who had a voiding cystourethrogram because of urinary tract infection. One girl who came in had constipation and acute urinary retention. The treatment for constipation consisted of disimpaction and maintenance treatment, which included the prevention of reaccumulation of stools and reconditioning to normal bowel habits through timed toilet sitting. Follow-up, at least 12 months after start of treatment for constipation, revealed that the constipation was relieved successfully in 52%. Relief of constipation resulted in disappearance of daytime urinary incontinence in 89% and nighttime urinary incontinence in 63% of patients, and disappearance of recurrent urinary tract infections in all patients who had no anatomic abnormality of the urinary tract. CONCLUSIONS Urinary symptoms were found in a significant number of children who had functional constipation and encopresis. With treatment of the constipation, most patients became clean and dry and further recurrence of urinary tract infections was prevented.