¹University "Tor Vergata" of Rome, Department of Systems Medicine, Rome, Italy, ²Internal Medicine and Gastroenterology - Complesso Integrato Columbus Catholic University, Complesso Integrato Columbus, Internal Medicine and Gastroenterology, Rome, Italy, ³Azienda Ospedaliera S.Camillo-Forlanini, Gastroenterology Unit, Rome, Italy, ⁴Federico II University, Gastroenterologia AOU, Gastroenterologia AOU, Naples, Naples, Italy, ⁵University of Padua, Department of Surgical, Oncological and Gastroenterological Sciences, Padua, Italy, ⁶A.O. Mauriziano, Gastroenterology Unit, Turin, Italy, ⁷S. Filippo Neri Hospital, Gastroenterology Unit, Rome, Italy, ⁸IRCCS ca' Granda, Ospedale Maggiore Policlinico Foundation University of Milan della Carita, Gastroenterology and Endoscopy Unit, Milan, Italy, ⁹University of Messina, Department of Clinical and Experimental Medicine, Clinical Unit for Chroric Bowel Disorders, Messina, Italy, ¹⁰University della Campania ‘Luigi Vanvitelli’, U.O. of Gastroenterology C.S., Naples, Italy, ¹¹Ospedale Maggiore, Unit PEDIATRIA, Bologna, Italy, ¹²Hospital Civico, Gastroenterology, Palermo, Italy, ¹³University "Tor Vergata" of Rome, GI Unit, Department of Systems Medicine, Rome, Italy, ¹⁴Federico II University, Gastroenterologia AOU, Naples, Italy, ¹⁵University, Department of Systems Medicine, Rome, Italy, ¹⁶Hospital Civico, Gastroenterology Unit, Palermo, Italy, ¹⁷IRCCS Policlinico S. Donato, San Donato Milanese, Gi Unit, Milan, Italy, ¹⁸AOU Careggi Univesrity Hospital, Gi Unit, Florence, Italy, ¹⁹Hospital ‘Riuniti Villa Sofia-Cervello’, Di.Bi.Mis., C.O.U. Of Internal Medicine, Palermo, Italy, ²⁰SOFAR Ospedale San Giuseppe, Gi Unit, Milan, Italy, ²¹Complesso Integrato Columbus Catholic University, Complesso Integrato Columbus, Internal Medicine and Gastroenterology, Rome, Italy

¹University Hospital Galway, Galway, Ireland, ²Univeristy Hospital Galway, Galway, Ireland

¹IRCCS Sacro Cuore Don Calabria, IBD Unit, Negrar, Italy, ²IRCCS Sacro Cuore Don Calabria, Rheumatology, Negrar, Italy

¹General Hospital of Nikea and Piraeus "Agios Panteleimon", Gastroenterology, Athens, Greece, ²General Hospital of Heraklion "Venizeleio", Gastroenterology, Heraklion, Greece, ³University General Hospital of Heraklion, Nephrology, Heraklion, Greece

¹Connolly Hospital and RCSI, Blanchardstown, Dublin 15, Department of Gastroenterology, Dublin, Ireland

¹GlaxoSmithKline, Stevenage, UK, ²GlaxoSmithKline, Upper Providence, USA, ³GlaxoSmithKline, London, UK, ⁴Adelphi Real World, Cheshire, UK

¹University Hospital Bratislava, 5th Department of Internal Medicine, Bratislava, Slovakia

¹Hospital Universitario de La Princesa, IIS-IP , Universidad Autónoma de Madrid and CIBEREHD, Gastroenterology Unit, Madrid, Spain, ²Ekineo Business Intelligence / www.in-pacient.es Barcelona, Spain

¹Brotzu Hospital, Gastroenterology Unit, Cagliari, Italy, ²San Martino Hospital, Endoscopy, Oristano, Italy, ³University of Sassari, Clinica Medica, Sassari, Italy, ⁴Territorial Gastroenterology, Sassari, Italy, ⁵Santissima Annunziata Hospital, Gastroenterology Unit, Sassari, Italy, ⁶University of Cagliari, Gastroenterology Unit, Cagliari, Italy, ⁷NS di Bonaria Hospital, Endoscopy, San Gavino, Italy

¹The Catholic University of Korea, Seoul, South Korea, ²Inje University Haeundae Paik, Pusan, South Korea, ³Hanyang University College of Medicine, Seoul, South Korea, ⁴Pusan National University School of Medicine, Pusan, South Korea, ⁵Seoul National University Hospital, Healthcare System Gangnam Center, Seoul, South Korea, ⁶Inje University Ilsan Paik Hospital, Gyeonggi, South Korea, ⁷Ewha Womans University School of Medicine, Seoul, South Korea

¹Sahloul Sousse, Gastroenterology, Sousse, Tunisia, ²Sahloul Sousse, Sousse, Tunisia

¹Hospital Universitario San Cecilio, UGC Aparato Digestivo, Granada, Spain

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