Randomized, Double-Blinded, Placebo-Controlled Trial of Laxatives for Children With Urge Syndrome

Urge Syndrome (US) is the most common non-neurogenic voiding dysfunction in children beyond the usual age for toilet training, and is characterized by urinary frequency and urgency, holding maneuvers, and diurnal incontinence. Urodynamics testing has determined these symptoms result from uninhibited bladder contractions, and so anticholinergic drugs that control these contractions are the mainstay of therapy typically given in six monthintervals until the condition resolves. Beyond the embarrassment that may accompany urinary incontinence, US has been linked to urinary tract infection (UTI) and vesicoureteral reflux. Specifically, among females with UTI, at least 40% also have US, and US has been identified as a cause for reflux and a factor that delays its otherwise expected spontaneous resolution. Consequently, identification and treatment of US are important to the management of children with UTI, reflux and/or incontinence.

Constipation also has been associated with UTI, vesicoureteral reflux, and urinary incontinence in children. Although these observations date at least to the 1950s, relatively few studies have attempted either to establish the incidence of constipation found with these various pediatric urologic conditions, or to document the impact of bowel therapy upon their management. Of these, Yazbeck et al studied 47 children with recurrent UTI and noted all were constipated and had uninhibited bladder contractions during urodynamics testing. Therapy directed toward relief of constipation resolved bladder symptoms in 25%. Loening-Baucke reported 46% of 234 children attending a university-based encopresis clinic also experienced urinary incontinence, which diminished with laxative therapy. A recent evaluation of 582 children with US estimated that 16% were also constipated based upon a history of bowel activity.

We have been concerned about the apparent association between US and constipation, especially since anticholinergic drugs commonly prescribed for uninhibited bladder contractions could exacerbate underlying stool retention and thereby prolong bladder dysfunction. It is also our experience that parents are not very familiar with bowel activity of their children after the usual age of toilet training, making history potentially unreliable for diagnosing constipation. Therefore, we started recommending a brief course of laxatives for all patients presenting with US, reserving anticholinergics for those whose bladder symptoms persisted. In a retrospective review of 110 children, we found 34% had relief of bladder symptoms with laxatives alone, so that anticholinergic medications were not then required, and the history of whether the child was constipated or not did not predict response. However, this study has been criticized for not being placebo-controlled.

Given the potential impact of this observation for the management of children with not only urinary incontinence but also UTI and reflux who have US, we now propose a prospective, randomized, double-blinded, placebo-controlled study of the impact of laxative therapy upon children with US.

Inclusion criteria

• Toilet-trained with a history of urinary tract infection
• Vesicoureteral reflux
• Urinary incontinence
• Daily frequency and urgency
• Diurnal incontinence.

Exclusion criteria

• Children who are below 4 years old as they may still not be toilet-trained;
• Children with encopresis
• Children with anorectal malformations
• Children with neurologic disorders