1. Department of Gastroenterology and Hepatology, Karolinska Institute, Karolinska University Hospital, Solna, Sweden;
2. Epidemiology Unit, Department of Medicine, Karolinska Institute, Karolinska University Hospital, Solna, Sweden;
3. IBD Unit, Karolinska Institute, Sophiahemmet, Stockholm, Sweden;
4. Department of Pathology and Cytology, Medilab, Täby, Sweden