1. Department of Surgery; Section of Coloproctology; Aarhus University Hospital; Aarhus Denmark
2. Department of Clinical Epidemiology; Aarhus University Hospital; Aarhus Denmark
3. Department of Surgery; Lillebaelt Hospital Kolding; Kolding Denmark
4. Gastroenterology Unit; Hvidovre Hospital; Hvidovre Denmark
5. Department of Surgical Gastroenterology A; Aalborg Hospital; Aalborg Denmark
6. Department of Surgery A; Odense University Hospital; Odense Denmark
7. Department of Surgery and Transplantation; Rigshospitalet; Copenhagen University Hospital; Copenhagen Denmark
8. Department of Surgery; Herlev Hospital; Herlev Denmark