1. Hospital Clínico Universidad de Chile, Department of Internal Medicine, Section of Gastroenterology, Santiago, Chile
2. Gastroenterology Section, Clínica Santa María, Santiago, Chile
3. Hospital Clínico Universidad de Chile, Intensive Care Unit, Santiago, Chile
4. Hospital Clínico Universidad de Chile, School of Medicine, Santiago, Chile
5. Clínica Las Condes, Department of Gastroenterology, Santiago, Chile
6. Hospital Clínico Universidad de Chile, Department of Pathology, Santiago, Chile