TY JOUR TI RARE FUNCTIONAL GASTRODUODENAL DISORDERS: FROM THEORY TO PRACTICE KW functional dyspepsia KW functional gastrointestinal disorders JO Medical Bulletin of the Ministry of Internal Affairs AU SERKOVA, M.Y. AU AVALUEVA, E.V. AU BAKULIN, I.G. PY 2025 IS 2025 PB State institution Joint editorial office of the Ministry of Internal Affairs of Russia