1. Department of Gastrointestinal and Emergency Surgery; Haukeland University Hospital; Bergen Norway
2. Department of Clinical Medicine; University of Bergen; Bergen Norway
3. Department of Anesthesiology; Haukeland University Hospital; Bergen Norway
4. Department of Gastrointestinal Surgery; Haugesund Hospital; Haugesund Norway
5. Department of Gastrointestinal Surgery; Stavanger University Hospital; Stavanger Norway