E.A. KOREYBA1, K.A. KOREYBA2 1Hospital for veterans of wars, Kazan 2Kazan State Medical University of the Ministry of Health of the Russian Federation, Kazan  Koreyba E.A. ― therapist ― gastroenterologist Address: 5 Isaev Str., Kazan, Russian Federation, 420039, tel. +7-927-426-26-38, e-mail: elenakorejba@yandex.ru Koreyba K.A. ― PhD (medicine), Associate Professor of the Department of Surgical Diseases, […]