Imperial College London - Department of Metabolism, Digestion and Reproduction, Imperial College London - Department of Metabolism, Digestion and Reproduction, Imperial College London - Department of Metabolism, Digestion and Reproduction, Imperial College London - Department of Metabolism, Digestion and Reproduction, University of Exeter - Exeter Inflammatory Bowel Disease and Pharmacogenetics Research Group, University of Exeter - IBD Pharmacogenetics Group, University of Exeter - Exeter Inflammatory Bowel Disease and Pharmacogenetics Research Group, University of Exeter - Exeter Inflammatory Bowel Disease and Pharmacogenetics Research Group, University of Exeter - Institute of Biomedical and Clinical Science, Newcastle University, Government of the United Kingdom - Department of Gastroenterology, Barts Health NHS Trust - Department of Gastroenterology, NHS Lothian - Department of Gastroenterology, Imperial College London - Department of Immunology and Inflammation, St Marks Hospital and Academic Institute - Department of Gastroenterology, Imperial College London, Imperial College London - Department of Infectious Disease, University of Exeter - Exeter Inflammatory Bowel Disease and Pharmacogenetics Research Group, University of Exeter - Exeter Inflammatory Bowel Disease and Pharmacogenetics Research Group, Royal Devon and Exeter NHS Foundation Trust - Department of Gastroenterology and Imperial College London - Department of Metabolism, Digestion and Reproduction