1. Division of General Surgery, Department of Surgery, Pourtales Neuchatel Hospital, Neuchatel, Switzerland
2. Division of Abdominal Surgery, Department of Surgery, Geneva University Hospitals, Geneva, Switzerland
3. Division of Gastroenterology, Department of Medicine, Pourtales Neuchatel Hospital, Neuchatel, Switzerland
4. Department of Clinical Pathology, Geneva University Hospitals, Geneva, Switzerland