1. Gastroenterology Department, Amato Lusitano Hospital, Castelo Branco, Portugal
2. Gastroenterology Department, Portuguese Oncology Institute of Porto, Porto, Portugal
3. Gastroenterology Department, Hospital of Braga, Braga, Portugal
4. Gastroenterology Department, Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal
5. Gastroenterology Department, Senhora da Oliveira Hospital, Guimarães, Portugal
6. Department of Surgery and Physiology, Porto Faculty of Medicine, Porto, Portugal
7. MEDCIDS/Porto Faculty of Medicine, Porto, Portugal