1. Department of Biological and Medical Psychology, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
2. Department of Clinical Medicine, University of Bergen, 5021 Bergen, Norway
3. National Center for Functional Gastrointestinal Disorders, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
4. Department of Biomedicine, University of Bergen, 5020 Bergen, Norway
5. Mohn Medical Imaging and Visualization Center, Department of Radiology, Haukeland University Hospital, 5021 Bergen, Norway