Gastrointestinal Endoscopy Unit, Hospital das Clínicas, University of São Paulo Medical School, Dr. Arnaldo Av, 455, São Paulo, 01246-903, Brazil. antonio_coutinho_neto@hotmail.com. Gastrointestinal Endoscopy Unit, Hospital das Clínicas, University of São Paulo Medical School, Dr. Arnaldo Av, 455, São Paulo, 01246-903, Brazil. Bariatric and Metabolic Surgery Unit, Hospital das Clínicas, University of São Paulo Medical School, São Paulo, Brazil.