1. Department of Gastroenterology, Faculdade de Medicina, Universidade de Sao Paulo, Carvalho Aguiar street, number 255, 6th floor, Sao Paulo 05422-090, Brazil
2. Department of Gastroenterology, Faculty of Medicine, University of Sao Paulo, São Paulo, Brazil
3. Division of Digestive and Liver Diseases, Columbia University Irving Medical Center, New York, NY, USA