1. Division of Gastroenterology, Department of Internal Medicine, CGH Medical Center, Sterling, IL, USA.
2. Division of Gastroenterology, Department of Internal Medicine, Georgia Regents University, Augusta, GA, USA.
3. Division of Gastroenterology, Department of Internal Medicine, Saint Francis Hospital, Evanston, IL, USA.
4. Division of Gastroenterology, Department of Internal Medicine, University of Tishreen, Latakia, Syria.