1. Department of Gastroenterology, Helsinki University Hospital, Vantaa, Finland;
2. Department of Gastroenterology and Alimentary Tract Surgery, Tampere University Hospital, Tampere, Finland;
3. Department of Gastroenterology and Alimentary Tract Surgery, Tampere University Hospital, Hatanpää Hospital, Tampere, Finland;
4. Nordic Healthcare Group, Helsinki, Finland;
5. Children and adolescents, Tampere University Hospital and University of Tampere, Tampere, Finland