1. Department of Gastrointestinal and Pediatric Surgery, Oslo University Hospital, P.O. Box 4950 Nydalen, N-0424 Oslo, Norway Institute of Clinical Medicine, University of Oslo, Oslo, Norway
2. Department of Gastrointestinal and Pediatric Surgery, Oslo University Hospital, Oslo, Norway
3. Institute of Clinical Medicine, University of Oslo, Oslo, Norway
4. College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
5. Division of Surgery and Perioperative Medicine, Flinders Medical Centre, Bedford Park, SA, Australia
6. Division of Digestive & Liver Diseases, Cedars-Sinai Medical Center, Los Angeles, CA, USA