¹Tzaneion General Hospital of Piraeus, Department of Gastroenterology, Piraeus, Greece

¹Sapporo Kosei General Hospital, Pediatrics, Sapporo, Japan, ²Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Pediatrics, Sapporo, Japan, ³Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Pediatrics and Developmental Biology, Tokyo, Japan

¹Hospital Universitario de La Princesa, ISS-IP, Universidad Autónoma de Madrid and CIBEREHD, Gastroenterology Unit, Madrid, Spain, ²Vall d'Hebron Research Institute, Rheumatology Research Group, Barcelona, Spain, ³Universitat Pompeu Fabra, Experimental and Health Sciences, Barcelona, Spain, ⁴Hospital Universitario de Fuenlabrada, Instituto de Investigación de La Paz (IdiPaz), Gastroenterology Unit, Madrid, Spain, ⁵Hospital Universitario y Politécnico de La Fe and CIBEREHD, Gastroenterology Unit, Valencia, Spain, ⁶Hospital Universitario de Galdakao, Gastroenterology Unit, Galdakao, Spain, ⁷Hospital Universitario de Donostia, Instituto Biodonostia, UPV/EHU, Ikerbasque and CIBEREHD, Gastroenterology Unit, San Sebastián, Spain, ⁸Hospital Universitario Clínico San Carlos and IdISSC, Gastroenterology Unit, Madrid, Spain, ⁹Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofía/Universidad de Córdoba, Gastroenterology Unit, Córdoba, Spain, ¹⁰Hospital Universitario Gregorio Marañón e IiSGM, Gastroenterology Unit, Madrid, Spain, ¹¹Hospital Universitario Clínico de Santiago, Gastroenterology Unit, Santiago de Compostela, Spain, ¹²Hospital Universitario Puerta de Hierro Majadahonda, Gastroenterology Unit, Madrid, Spain, ¹³Hospital Universitario La Paz, Gastroenterology Unit, Madrid, Spain, ¹⁴Universidad de Alcalá, Alcalá de Henares, Spain, ¹⁵IdiPaz. Hospital Universitario La Paz, Immuno-Rheumatology Research Group, Madrid, Spain, ¹⁶Hospital Universitario Ramón y Cajal, Gastroenterology Unit, Madrid, Spain, ¹⁷Hospital Universitario Alicante, Gastroenterology Unit, Alicante, Spain, ¹⁸Hospital Lozano Blesa, IIS Aragón and CIBERehd, Gastroenterology Unit, Zaragoza, Spain, ¹⁹Hospital Universitario Manises, Gastroenterology Unit, Valencia, Spain

¹Military University Hospital and Charles University, Department of Internal Medicine, First Faculty of Medicine, Prague, Czech Republic, ²Genomac Research Institute, Center for Applied Genomics of Solid Tumours (CEGES), Prague, Czech Republic, ³Military University Hospital and Charles University, Surgical Clinic, Second Faculty of Medicine, Prague, Czech Republic, ⁴ISCARE, a.s., IBD centre, Prague, Czech Republic

¹The Sixth Affiliated Hospital of Sun Yat-sen University, Department of Colorectal Surgery, Guangzhou, China, ²Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China

¹University Medical Center Groningen, Paediatric Gastroenterology, Groningen, The Netherlands, ²University Medical Center Groningen, Gastroenterology and Hepatology, Groningen, The Netherlands, ³Erasmus University Medical Center, Paediatric Gastroenterology, Rotterdam, The Netherlands, ⁴VU University Medical Center, Paediatric Gastroenterology, Amsterdam, The Netherlands, ⁵Emma Children's Hospital - Amsterdam UMC, Paediatric Gastroenterology, Amsterdam, The Netherlands, ⁶University Medical Center Utrecht, Paediatric Gastroenterology, Utrecht, The Netherlands, ⁷Isala Hospital, Paediatrics, Zwolle, The Netherlands, ⁸Broad Institute of Harvard and Massachusetts Institute of Technology, Boston, USA, ⁹Massachusetts General Hospital, Gastroenterology, Boston, USA, ¹⁰Stanford University, Stanford, USA, ¹¹University Medical Center Groningen, Genetics, Groningen, The Netherlands

¹KU Leuven, Department of Human Genetics, Laboratory of Complex Genetics, Leuven, Belgium, ²University of Ulsan College of Medicine, Department of Biochemistry and Molecular Biology, Seoul, South Korea, ³KU Leuven, Department Chronic Diseases, Metabolism & Ageing (CHROMETA), Translational Research Center for Gastrointestinal Disorders (TARGID), Leuven, Belgium, ⁴University Hospitals Leuven, Department of Gastroenterology and Hepatology, Leuven, Belgium

¹KU Leuven, Department of Human Genetics, Leuven, Belgium, ²KU Leuven, Department of Chronic Diseases, Metabolism and Ageing (CHROMETA), Leuven, Belgium, ³University Hospitals Leuven, Department of Gastroenterology and Hepatology, Leuven, Belgium, ⁴University Hospitals Brussels, Department of Gastroenterology, Brussels, Belgium, ⁵University Hospital of Ghent, Department of Gastroenterology, Ghent, Belgium

¹Mater Dei Hospital, Gastroenterology, Msida, Malta, ²University of Malta, Department of Biochemistry, Msida, Malta, ³Christian-Albrechts-University of Kiel, Institute of Clinical Molecular Biology, Kiel, Germany

¹University of the Faroe Islands, Department of Health and Nursing Sciences, Tórshavn, Faroe Islands, ²National Hospital of the Faroe Islands, Department of Medicine, Tórshavn, Faroe Islands, ³Genetic Biobank of the Faroe Islands, FarGen, Tórshavn, Faroe Islands, ⁴Genetic Biobank of the Faroe Islands, Tórshavn, Faroe Islands

¹Mater Dei Hospital, Gastroenterology, Msida, Malta, ²University of Malta, Department of Biochemistry, Msida, Malta, ³Christian-Albrechts-University of Kiel, Institute of Clinical Molecular Biology, Kiel, Germany

¹Mater Dei Hospital, Gastroenterology, Msida, Malta, ²University of Malta, Department of Biochemistry, Msida, Malta, ³Christian-Albrechts-University Kiel, Institute of Clinical Molecular Biology, Kiel, Germany

¹Pauls Stradins Clinical University Hospital, Gastroenterology, hepatology and nutrition center, Riga, Latvia, ²University of Latvia, Riga, Latvia, ³Latvian Biomedical Research and Study centre, Riga, Latvia

¹KU Leuven, Department of Human Genetics, Leuven, Belgium, ²KU Leuven, Department of Chronic Diseases, Metabolism and Ageing (CHROMETA), Leuven, Belgium, ³University Hospitals Leuven, Department of Gastroenterology and Hepatology, Leuven, Belgium, ⁴University Hospital of Ghent, Department of Gastroenterology, Ghent, Belgium, ⁵University Hospitals Brussels, Department of Gastroenterology, Brussels, Belgium

¹Medical School, National and Kapodistrian University of Athens, Biology, Athens, Greece, ²Department of Medicine, Democritus University of Thrace, Alexandroupolis, Greece, ³Institute of Clinical Molecular Biology, Christian-Albrechts-Universität zu Kiel, Kiel, Kiel, Germany, ⁴Bioinformatics ERA Chair, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus

¹Norwegian University of Science and Technology (NTNU), Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Trondheim, Norway, ²Liaison Committee between the Central Norway Regional Health Authority (RHA) and NTNU, Trondheim, Norway, ³St. Olav’s Hospital, Trondheim University Hospital, Department of Gastroenterology and Hepatology, Trondheim, Norway, ⁴St. Olav’s Hospital, Trondheim University Hospital, Department of Clinical Pharmacology, Trondheim, Norway, ⁵Norwegian University of Science and Technology (NTNU), Centre of Molecular Inflammation Research, Trondheim, Norway, ⁶St. Olav’s Hospital, Trondheim University Hospital, Department of Pathology, Trondheim, Norway

¹The Chinese University of Hong Kong, Medicine and Therapeutics, Hong Kong, Hong Kong, ²Université Clermont Auvergne, Inserm U1071, Clermont Ferrand, France, ³The Chinese University of Honk Kong, Center for Gut Microbiota Research, Hong Kong, Hong Kong

¹The Chinese University of Hong Kong, Hong Kong, Hong Kong, ²The General Hospital of the People's Liberation Army, Beijing, China

¹Dalhousie University, Department of Biology, Halifax, Canada, ²Dalhousie University, Department of Mathematics & Statistics, Halifax, Canada, ³PIBD Research Center Paediatric gastroenterology and Nutrition Unit, Wolfson Medical Center, Holon, Israel, ⁴Institute for Gastroenterology, Nutrition and Liver Diseases, Schneider Children’s Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Tel Aviv, Israel, ⁵Division of Pediatric Gastroenterology and nutrition, Department of Pediatrics, University of Alberta, Canada, Edmonton, Canada, ⁶IWK Health Centre / Dalhousie University, Pediatric Gastroenterology, Halifax, Canada

¹Venizeleio General Hospital, Gastroenterology, Heraklion, Greece