1. Clinic of Gastroenterology, Medical Park Private Tarsus Hospital, Mersin, Turkey
2. Division of Gastroenterology and Hepatology, Lynda K and David M Underwood Center for Digestive Disorders, Houston Methodist Hospital and Weill Cornell Medical College, Houston, TX, USA
3. Clinic of Gastroenterology, Adana Numune Research and Education Hospital, University of Health Sciences, Adana, Turkey