1. Sjøkanten legesenter and Bjarkøy legekontor, Harstad, Norway;
2. Department of Gastroenterology, University Hospital of Northern Norway, Harstad, Norway;
3. Department of Gastroenterology, The Arctic University of Norway, Tromsø, Norway;
4. Department of Gastroenterology Tromsø, University Hospital of Northern Norway, Norway;
5. Department of Clinical Pathology, University Hospital of Northern Norway, Tromsø, Norway;
6. Department of Community Medicine, UiT, National Centre of Rural Medicine, The Arctic University of Norway, Tromsø, Norway