1. Division of Clinical Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, University of São Paulo School of Medicine (HCFMUSP), São Paulo 05403-900, Brazil
2. Instituto Alfa de Gastroenterologia, Hospital das Clínicas, Federal University of Minas Gerais (UFMG), Belo Horizonte 30130-100, Brazil
3. Division of Gastroenterology (Gastrocentro), School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-894, Brazil
4. Gastroenterology Division, Ribeirão Preto Medical School, University of São Paulo (FMRP-USP), Ribeirão Preto 14049-900, Brazil