¹University Hospital of Heraklion, Department of Gastroenterology, Heraklion, Greece, ²Evangelismos Hospital, Gastroenterology Unit, Athens, Greece, ³Venizeleion General Hospital, Department of Gastroenterology, Heraklion, Greece

¹Hospital Universitario de Fuenlabrada, Gastroenterology, Fuenlabrada, Spain, ²Hospital Universitario de Fuenlabrada, Pharmacy, Fuenlabrada, Spain, ³Hospital Universitario de Fuenlabrada, Radiology, Fuenlabrada, Spain

¹Imperial College London, Department of Surgery and Cancer, London, UK, ²St Mark's Hospital and Academic Institute, Surgical Epidemiology Trials and Outcome Centre, London, UK, ³Karolinska Institutet, Department of Molecular Medicine and Surgery, Stockholm, Sweden, ⁴Karolinska University Hospital, Center for Digestive Disease, Division of Coloproctology, Stockholm, Sweden, ⁵University Hospitals Birmingham, Academic Department of Surgery, Birmingham, UK, ⁶St Mark's Hospital and Academic Institute, London, UK, ⁷Karolinska Institutet, Clinical Epidemiology Unit, Department of Medicine, Stockholm, Sweden, ⁸Karolinska Institutet, Sachs’ Children and Youth Hospital, Stockholm South General Hospital, and Department of Clinical Science and Education Södersjukhuset, Stockholm, Sweden, ⁹Karolinska Institutet, Unit of Biostatistics, Institute of Environmental Medicine, Stockholm, Sweden, ¹⁰Linköping University, Division of Surgery, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping, Sweden, ¹¹County Council of Östergötland, Department of Surgery, Linköping, Sweden

¹North Zealand University Hospital, Department of Gastroenterology, Frederikssund, Denmark, ²Mater Dei Hospital, Division of Gastroenterology, L-Imsida, Malta, ³St Mark's Hospital, Gastroenterology, London, UK, ⁴Nicosia Private practice, Nicosia Private practice, Nicosia, Cyprus, ⁵Azienda Ospedaliera di Padova, Department of Surgery, Oncology and Gastroenterology, Padova, Italy, ⁶Viborg Regional Hospital, Medical Department, Viborg, Denmark, ⁷Hospital of Southern Jutland, Medical Department, Aabenraa, Denmark, ⁸Moscow Regional Research Clinical Institute, Department of Gastroenterology, Moscow, Russian Federation, ⁹Complexo Hospitalario Universitario de Vigo, Gastroenterology Department, Vigo, Spain, ¹⁰Semmelweis University, 1st Department of Medicine, Budapest, Hungary, ¹¹State University of Medicine and Pharmacy of the Republic of Moldova, Department of Gastroenterology, Chisinau, Moldova, Republic of, ¹²University of Porto, Institute for molecular and cell biology, Porto, Portugal, ¹³Hospital de São João, Department of Gastroenterology, Porto, Portugal, ¹⁴Oporto Medical School, Institute of Pharmacology and Therapeutics, Porto, Portugal, ¹⁵Lithuanian University of Health Sciences, Institute for Digestive Research, Kaunas, Lithuania, ¹⁶Faculty of Medicine and Health, Örebro University, Department of Gastronterology, Örebro, Sweden, ¹⁷Charles University, IBD Center ISCARE, Prague, Czech Republic, ¹⁸Herning Central Hospital, Department of medicine, Herning, Denmark, ¹⁹University of Medicine ‘Victor Babes’, Clinic of Gastroenterology, Timisoara, Romania, ²⁰Aarhus University Hospital, Department of Hepatology and Gastroenterology, Aarhus, Denmark, ²¹Tampere University Hospital, Department of Gastroenterology and Alimentary Tract Surgery, Tampere, Finland, ²²University Hospital Center Zagreb, University of Zagreb School of Medicine, Division of Gastroenterology and Hepatology, Zagreb, Croatia, ²³Amiens University and Hospital, Epimad Registry, Gastroenterology Unit, Amiens, France, ²⁴Soroka Medical Center and Ben Gurion University of the Negev, Department of Gastroenterology and Hepatology, Beer Sheva, Israel, ²⁵The National Hospital of the Faroe Islands, Medical department, Tórshavn, Faroe Islands, ²⁶Department of Gastroenterology and Digestive Endoscopy, Morgagni Hospital, Forli, Italy, ²⁷Slagelse Hospital, Department of Gastroenterology, Slagelse, Denmark, ²⁸AOU Careggi Regional Referral Center for Inflammatory Bowel Disease, Gastroenterology Department, Florence, Italy, ²⁹Tartu University Hospital, Division of Endocrinology and Gastroenterology, Tartu, Estonia, ³⁰University Hospital, Ioannina, 1st Division of Internal Medicine and Hepato-Gastroenterology Unit, Ioannina, Greece, ³¹Gentofte Hospital, Department of Medical Gastroenterology, Copenhagen, Denmark

Gastrounit, Hvidovre Hospital, Gastroenterology, Copenhagen, Denmark

¹University Medical Center Groningen, Gastroenterology and Hepatology, Groningen, The Netherlands, ²University Medical Center Groningen, Epidemiology, Groningen, The Netherlands, ³University Medical Center Groningen, Genetics, Groningen, The Netherlands, ⁴University Medical Center Groningen, Medical Microbiology, Groningen, The Netherlands

¹University Medical Center Groningen, Gastroenterology and Hepatology, Groningen, The Netherlands, ²University Medical Center Groningen, Epidemiology, Groningen, The Netherlands

¹Oslo University Hospital, Department of Gastroenterology, Oslo, Norway, ²University of Oslo, Department of Nursing Science, Oslo, Norway, ³Akershus University Hospital, Department of Gastroenterology, Nordbyhagen, Norway, ⁴Telemark Hospital Trust, Skien, Skien, Norway, ⁵Oslo University Hospital, Department of Pediatrics, Oslo, Norway, ⁶Akershus University Hospital, Department of Pediatrics, Nordbyhagen, Norway, ⁷Diakonhjemmet Hospital, Department of Gastroenterology, Oslo, Norway, ⁸Lovisenberg Diaconal Hospital, Department of Medicine, Oslo, Norway, ⁹Innlandet Hospital Trust Kongsvinger, Kongsvinger, Norway, ¹⁰Innlandet Hospital Trust Lillehammer, Pediatric Department, Lillehammer, Norway, ¹¹Innlandet Hospital Trust Elverum, Department of Medicine, Elverum, Norway, ¹²Innlandet Hospital Trust Elverum, Department of Pediatrics, Elverum, Norway, ¹³Sykehuset Innlandet Hamar, Department of Medicine, Hamar, Norway, ¹⁴Innlandet Hospital Trust Gjøvik, Department of Medicine, Gjøvik, Norway, ¹⁵University of Oslo, Oslo, Norway, ¹⁶Vestre Viken Hospital Trust Bærum, Department of Gastroenterology, Bærum, Norway, ¹⁷Vestre Viken Hospital Trust Drammen, Department of Pediatric and Adolescent Medicine, Drammen, Norway, ¹⁸Vestre Viken Hospital Trust Kongsberg, Department of Medicine, Kongsberg, Norway, ¹⁹Vestfold Hospital Trust, Tonsberg, Department of Pediatrics, Tonsberg, Norway, ²⁰Telemark Hospital Trust Skien, Department of Pediatrics, Skien, Norway, ²¹Telemark Hospital Trust Notodden, Department of Medicine, Notodden, Norway, ²²Østfold Hospital Trust, Department of Gastroenterology, Grålum, Norway, ²³Østfold Hospital Trust, Department of Pediatrics, Grålum, Norway, ²⁴Institute of Public Health, Oslo, Norway, ²⁵Sørlandet Hospital Kristiansand, Department of Gastroenterology, Kristiansand, Norway, ²⁶Sørlandet Hospital Arendal, Department of Gastroenterology, Arendal, Norway, ²⁷Sørlandet Hospital Arendal, Department of Pediatrics, Arendal, Norway, ²⁸Sørlandet Hospital Flekkefjord, Department of Medicine, Flekkefjord, Norway

¹APHP, Paris, France, ²Hopital Montfermeil, Montfermeil, France, ³Hopital Saint Louis, Paris, France, ⁴Hopital de Lille, Lille, France, ⁵Hopital Saint Antoine, Paris, France, ⁶Hopital de Cochin, Paris, France, ⁷Hopital de Nancy, Nancy, France, ⁸Hopital de Clermont Ferrand, Clermont-Ferrand, France, ⁹Hopital de Nice, Nice, France, ¹⁰Hopital Montpellier, Montpellier, France, ¹¹Hopital de Vendée, Vendée, France, ¹²CHIC, Créteil, France, ¹³Centre Hospitalier Annecy, Annecy, France, ¹⁴Hopital de Colmar, Colmar, France, ¹⁵Orange, Orange, France, ¹⁶Hopital de Nantes, Nantes, France, ¹⁷Hopital de Beaujon, Clichy, France, ¹⁸Hopital saint brieuc, Saint brieuc, France, ¹⁹Hopital de tours, Tours, France, ²⁰CH valenciennes, Valenciennes, France, ²¹hopital Quimper, Quimper, France, ²²Hopital Dreux, Dreux, France, ²³Hopital de Meaux, Meaux, France

¹Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of medicine, Seoul, South Korea, ²Samsung Medical Center, Sungkyunkwan University School of Medicine, Statistics and Data Center, Seoul, South Korea, ³Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Social and Preventive Medicine, Seoul, South Korea

¹St George's Healthcare NHS Trust, Gastroenterology, London, UK, ²Imperial College London, School of Public Health, London, UK

¹UCL, Institute of Health Informatics, London, UK, ²Stanford University, Stanford, USA, ³UCL, Institute of Cardiovascular Sciences, London, UK

¹University of Edinburgh, Department of Child Life and Health, Edinburgh, UK, ²Royal Hospital For Sick Children, Department of Gastroenterology and Nutrition, Edinburgh, UK, ³Royal Hospital For Sick Children, Department of Paediatric Surgery, Edinburgh, UK

¹IBD clinical and research centre, Iscare, Prague, Czech Republic, ²Public Health, Epidemiology and Economic Health, Registre Epimad, Maison Régionale de la Recherche Clinique, Lille University and Hospital, Lille, France, ³Lille Inflammation Research International Center LIRIC - UMR 995 Inserm Lille 2 University, CHRU de Lille, Lille, France, ⁴Gastroenterology Unit, Epimad Registry, Hôpital Charles Nicolle, Rouen University Hospital, Rouen, France, ⁵Gastroenterology Unit, Hôpital Huriez, Lille University Hospital, Lille, France, ⁶Gastroenterology Unit, Rennes University Hospital, Rennes, France, ⁷Division of Gastroenterology, Hepatology and Nutrition, Department of Paediatrics, Lille University Jeanne de Flandre Children’s Hospital, University of Lille, Lille, France, ⁸Dermatology Unit, Hôpital Huriez, Lille University Hospital, Lille, France, ⁹Gastroenterology Unit, Inserm U954, Nancy University and Hospital, Nancy, France, ¹⁰Gastroenterology Unit, Epimad Registry, CHU Amiens Sud, l, Amiens University Hospital, Amiens, France

¹Inselspital, Bern, Department of Gastroenterology, Bern, Switzerland, ²Universitätsspital, Gastroenterology, Zürich, Switzerland, ³Stadtspital Triemli, Gastroenterology, Zürich, Switzerland, ⁴CHUV, Gastroenterology, Lausanne, Switzerland, ⁵CHUV, PMU, Lausanne, Switzerland, ⁶CHUV, Statistics, Lausanne, Switzerland, ⁷Hôpital Saint-Louis, Gastroenterology, Lausanne, France, ⁸Inselpital, Gastroenterology, Bern, Switzerland, ⁹Inselspital, Gastroenterology, Bern, Switzerland

¹Seoul National University College of Medicine, Department of Internal Medicine, Seoul, South Korea, ²College of Medicine, The Catholic University of Korea, Dept of Medical Statistics, Seoul, South Korea

¹Gastroenterology Section, Hospital Ramón y Cajal, Madrid, Spain, ²Hospital Universitario Virgen Macarena, Sevilla, Spain, ³Unitat de Malalties Digestives. Corporació Sanitaria Universitària Parc Taulí, Sabadell, Spain, ⁴Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain, ⁵Merck Sharp & Dohme, Spain, Medical Affairs, Madrid, Spain, ⁶Servicio de Gastroenterología Complexo Hospitalario Universitario de Pontevedra, Pontevedra, Spain, ⁷Instituto de Investigación Biomedica (IBI). SERGAS, Pontevedra, Spain

¹Montefiore Medical Center, Bronx, USA, ²Albert Einstein College of Medicine, Bronx, USA, ³Weill Cornell Medical College, New York, USA, ⁴Icahn School of Medicine at Mount Sinai, New York, USA, ⁵Columbia University Medical Center, New York, USA

¹University Hospital of Burgos, Department of Gastroenterology, Burgos, Spain, ²University Hospital Rio Hortega, Department of Gastroenterology, Valladolid, Spain, ³University Hospital Clinic Valladolid, Department of Gastroenterology, Valladolid, Spain, ⁴Hospital Virgen de la Concha, Department of Gastroenterology, Zamora, Spain

¹University of Szeged, 1st Department of Medicine, Szeged, Hungary, ²University of Szeged, Department of Medical Physics and Informatics, Szeged, Hungary