Objective: To provide recommendations for the collection and management of multisource and multimethod data in studies of children and adolescents with pediatric conditions.

We have previously demonstrated the clinical efficacy of montelukast in a randomized double-blind controlled cross-over trial in patients with dyspepsia in association with duodenal eosinophilia. The mechanism of this clinical response is unknown but could involve a decrease in eosinophil density or activation.