¹Department of General Surgery, New Cross Hospital, Wolverhampton, UK, ²Department of General Surgery, Academic Foundation Trainee, Wolverhampton, UK

Department of Gastroenterology and Hepatology, Graduate School of Medicine, Kyoto University, Kyoto, Japan

University of Rome Tor Vergata, Gastroenterology, Rome, Italy

The Jikei University School of Medicine, Gastroenterology and Hepatology, Tokyo, Japan

¹St Mark’s Hospital and Academic Institute, Department of Radiology, London, UK, ²St Mark’s Hospital and Academic Institute, Fistula Research Unit, London, UK, ³St Mark’s Hospital and Academic Institute, Colorectal surgery, London, UK, ⁴St Mark’s Hospital and Academic Institute, Department of Gastroenterology, London, UK

Theagenion CHT, Gastroenterology, Thessaloniki, Greece

University of California San Diego, Department of Gastroenterology, San Diego, USA

¹Rabin Medical Center, Division of Gastroenterology, Petah Tikva, Israel, ²Asian Institute of Gastroenterology, Gastroenterology, Hyderabad, India

¹Mathematical Institute, University of Oxford, Oxford, UK, ²Translational Gastroenterology Unit, Oxford University Hospitals NHS Foundation Trust, Oxford, UK, ³Oxford AHSN, Translational Gastroenterology Unit, Oxford, UK

¹IRCCS Sacro Cuore - Don Calabria, IBD Unit, Negrar di Valpolicella, Italy, ²Ospedale S. Maria Nuova, Gastroenterology Unit, Reggio Emilia, Italy, ³University of L’Aquila, Gastroenterology Unit, L’Aquila, Italy, ⁴IRCCS Sacro Cuore - Don Calabria, Rheumatology Unit, Negrar di Valpolicella, Italy, ⁵Ospedale S. Maria Nuova, Rheumatology Department, Reggio Emilia, Italy

¹Royal London Hospital, Paediatric Gastroenterology, London, UK, ²Barts Health NHS Trust, Pathology, London, UK

¹Complejo Hospitalario de Navarra, Gastroenterology and Hepatology, Pamplona, Spain, ²Hospital García Orcoyen, Gastroenterology and Hepatology, Estella, Spain

Department of Gastroenterology and Hepatology, ErasmusMC, Rotterdam, The Netherlands

¹Division of Gastroenterology, Department of Internal Medicine, University of Debrecen, Debrecen, Hungary, ²Inova Diagnostics, Inc., San Diego, USA, ³Department of Laboratory Medicine, University of Debrecen, Debrecen, Hungary

¹Faculty of Medicine-St George and Sutherland Clinical School, UNSW Sydney Australia, Sydney, Australia, ²School of Psychiatry, UNSW Sydney Australia, Sydney, Australia, ³School of Biotechnology and Biomolecular Sciences, UNSW Sydney Australia, Sydney, Australia

¹The Research Group of Gastrointestinal Disorders, 1The Hospital District of South OstroBothnia, Internal Medicine, Seinäjoki, Finland, ²Tampere University- Tampere University Hospital, Department of Gastroenterology and Alimentary Tract Surgery, Tampere, Finland, ³Tampere University, Faculty of Social Sciences, Tampere, Finland, ⁴Tampere University Hospital, Department of Gastroenterology and Alimentary Tract Surgery, Tampere, Finland

¹National Institute of Medical Science and Nutrition Salvador Zubiran, Department of Gastroenterology, Mexico City, Mexico, ²IBD Clinic- Department of Gastroenterology, Instituto Nacional de Ciencias Medicas y Nutrition, Gastroenterology, Mexico, Mexico

¹Marqués de Valdecilla University Hospital, Gastroenterology, Santander- Cantabria, Spain, ²Sierrallana Hospital, Gastroenterology, Torrelavega-Cantabria, Spain

Gastroenterology and Hepatology Section, PROMISE, University of Palermo, Palermo, Italy

¹Department of Internal Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey, ²Department of Gastroenterology, Istanbul University-Cerrahpasa, Istanbul, Turkey