Residual urine in children with acute cystitis and in healthy children: assessment by sonography.

Residual urine was assessed by ultrasound in children with single attacks of symptomatic lower urinary tract infection and in healthy controls. Residual urine was found significantly more often in the 39 patients during acute illness as well as during a follow-up of 6 months, compared to 55 control children. Infections caused by P-fimbriated Escherichia coli were not more often associated with residual urine than infections with nonP-fimbriated Escherichia coli or other bacterial species. It is suggested that residual urine is a facilitating host factor among others in the pathogenesis of symptomatic urinary tract infection in childhood.