Aalborg University - Center for Molecular Prediction of Inflammatory Bowel Disease (PREDICT), Zealand University Hospital - Section of Gastroenterology, Statens Serums Institut - Department of Epidemiology Research, Aalborg University - Center for Molecular Prediction of Inflammatory Bowel Disease (PREDICT), Aalborg University - Center for Molecular Prediction of Inflammatory Bowel Disease (PREDICT), Sorbonne University - Institut Pierre-Louis d'Epidémiologie et de Santé Publique, Université Paris VI Pierre et Marie Curie - Department of Gastroenterology and Aalborg University - Center for Molecular Prediction of Inflammatory Bowel Disease (PREDICT)