1 Gastroenterology Department, Centro Hospitalar e Universitário São João, Al. Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.
2 Faculty of Medicine, University of Porto, Porto, Portugal.
3 Gastroenterology Department, Centro Hospitalar e Universitário São João, Al. Prof. Hernâni Monteiro, 4200-319, Porto, Portugal. marcocostasilva87@gmail.com.
4 Faculty of Medicine, University of Porto, Porto, Portugal. marcocostasilva87@gmail.com.