1. Department of Paediatric and Adolescence Medicine, Copenhagen University Hospital , Amager and Hvidovre, Hvidovre , Denmark
2. Copenhagen Center for Inflammatory Bowel Disease in Children, Adolescents and Adults, Copenhagen University Hospital , Amager and Hvidovre, Hvidovre , Denmark
3. Gastrounit, Medical Division, Copenhagen University Hospital , Amager and Hvidovre, Hvidovre , Denmark
4. Department of Medicine and Community Health Sciences, University of Calgary , Calgary, Alberta , Canada