D. V. Kharitonov
Tula State University; Tula Children’s Regional Clinical Hospital
Russian Federation

Dmitry V. Kharitonov, Hospital Chief Executive Officer; Lecturer in the Pediatrics Department 

92 Lenin Avenue, Tula, 300012, Russia

39 Bondarenko Str., Tula, 300010, Russia 

V. G. Sapozhnikov
Tula State University; Tula Children’s Regional Clinical Hospital
Russian Federation

Vladimir G. Sapozhnikov, Doctor of Medical Sciences, prof., Head of the Pediatrics Department 

92 Lenin Avenue, Tula, 300012, Russia

39 Bondarenko Str., Tula, 300010, Russia 

N. V. Osiptsov
Tula State University; Tula Children’s Regional Clinical Hospital
Russian Federation

Osiptsov N. Vladimirovich, Head of the Endoscopy Department 

39 Bondarenko Str., Tula, 300010, Russia 

Yu. I. Nikishina
Tula State University; Tula Children’s Regional Clinical Hospital
Russian Federation

Nikishina Yu. Igorevna, Attending physician 

39 Bondarenko Str., Tula, 300010, Russia