1 Department of Gastroenterology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330077, Chile; Endoscopy Unit, Hospital UC-Christus, Santiago, Chile.
2 Department of Gastroenterology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330077, Chile; Endoscopy Unit, Hospital UC-Christus, Santiago, Chile. Electronic address: aoespino@uc.cl.