Duodenitis, also known as hemorrhagic duodenitis, is related to gastritis and eosinophilic gastritis. An important gene associated with Duodenitis is GAST (Gastrin), and among its related pathways/superpathways are NF-kappaB Signaling and Innate Lymphoid Cells Differentiation. The drugs Immunologic Factors and Contraceptive Agents have been mentioned in the context of this disorder. Affiliated tissues include small intestine and pancreas, and related phenotypes are homeostasis/metabolism and endocrine/exocrine gland