[1]Department of Gastroenterology;
the Centro Hospitalar Sao Joao;
WGO Training Center;
Faculty of Medicine;
University of Porto;
4200-319 Porto;
Portugal;
[1]Department of Gastroenterology;
the Centro Hospitalar Sao Joao;
WGO Training Center;
Faculty of Medicine;
University of Porto;
4200-319 Porto;
Portugal;