1. Gastroenterology Department, Centro Hospitalar de Lisboa Central, Lisbon, Portugal
2. Gastroenterology Department, Centro Hospitalar de Leiria, Leiria, Portugal
3. Department of Gastroenterology and Hepatology, Westmead Hospital, Sydney, New South Wales, Australia
4. Gastroenterology Department, Portuguese Oncology Institute of Porto, Porto, Portugal
5. CINTESIS/MEDCIDS, Porto Faculty of Medicine, Portugal
6. Westmead Clinical School, University of Sydney, New South Wales, Australia