Development of a core outcome set for clinical trials in childhood constipation: a study using a Delphi technique.

Objective: Patients, their parents and healthcare professionals (HCPs) have a different perception regarding the symptoms of functional constipation (FC). Consequently, a lack of agreement exists on definitions and outcomes used in therapeutic trials of FC. Therefore, our aim was to develop a core outcome set (COS) for FC for children aged 0-1 year and 1-18 years.