1. Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran
2. Department of Internal Medicine, Emam Khomeini Hospital, Ardabil University of Medical Sciences, Ardabil, Iran
3. Caspian Digestive Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran
4. GI Cancer Screening and Prevention Research Center, Guilan University of Medical Sciences, Rasht, Iran