occurs in occurs in phenotype affects entity inflammatory response Abnormal duodenum morphology Duodenitis 2020-09-03T12:01:20Z Duodenal inflammation Inflammation of the lining of the upper small intestine (duodenum). The diagnosis of duodenitis is made when there is infiltration by inflammatory cells with changes in villous architecture and surface and crypt epithelium. Duodenitis can be graded according to the amount of neutrophilic and plasma cell infiltration, villous height, Brunner's gland hyperplasia with prolapse into the lamina propria and gastric metaplasia. duodenum