1 Department of Gastroenterology, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, 8 Fanariou St, Byzantio, 551 33, Thessaloniki, Macedonia, Greece. jannis@auth.gr.
2 Department of Gastroenterology, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, 8 Fanariou St, Byzantio, 551 33, Thessaloniki, Macedonia, Greece.