Diagnostic utility of the water load test in children with chronic abdominal pain.

Objectives: To compare water load test consumption patterns between children with functional gastrointestinal disorders and healthy control children.

Methods: Seventy-one children with recurrent abdominal pain completed the Behavioral Assessment Scale for Children-Self-Report Form and the Questionnaire on Pediatric Gastrointestinal Symptoms during their first visit to a pediatric gastroenterology clinic. Parent- and child-report functional gastrointestinal diagnoses were based on the Questionnaire on Pediatric Gastrointestinal Symptoms scoring criteria, whereas the clinician's diagnosis was based on clinical impression from history and physical examination completed at this visit. Twenty-six healthy children also participated as controls. Statistical comparisons involved Student t tests, whereas receiver operating characteristic curves estimated sensitivity/specificity of the water load test and linear regression determined the amount of variance accounted for in water volume consumption.

Results: Children with recurrent abdominal pain, particularly those with a diagnosis of functional dyspepsia, consumed less water than healthy children on the water load test. The water load test demonstrated good specificity, but poor sensitivity, in identifying patients with functional dyspepsia. Clinician evaluation provided the greatest differentiation between functional gastrointestinal disorders on the water load test.

Conclusions: The water load test seems to be a poor diagnostic test for functional dyspepsia because of poor sensitivity. However, future research should examine whether the water load test is identifying a subset of children with functional dyspepsia experiencing a specific mechanosensory dysfunction and whether the water load test can predict clinical response to specific therapeutic interventions.