megaduodenum

noun

mega·​du·​o·​de·​num ˌmeg-ə-ˌd(y)ü-ə-ˈdē-nəm; -d(y)u̇-ˈäd-ᵊn-əm 

plural megaduodena -ˈdē-nə; -ᵊn-ə  or megaduodenums

: a congenital or acquired dilation and elongation of the duodenum with hypertrophy of all layers that presents as a feeling of gastric fullness, epigastric pain, belching, heartburn, and nausea with vomiting sometimes of food eaten 24 hours before