duodenitis duodenitis duodenitis is inflammation of the duodenum. it may persist acutely or chronically. duodenitisduodenum(marked)specialtygastroenterology symptoms known symptoms of duodenitis include: abdominal pain vomiting nausea discomfort in stomach causes known causes of duodenitis include: helicobacter pylori infection coeliac disease bacterial infection viral infection nsaids autoimmune diseases (i.e. crohn's disease) duodenal lymphocytosis idiopathic type acute duodenitis chronic duodenitis diagnosis diagnosis is generally made by endoscopy with biopsy to evaluate histology. review of symptoms and associated conditions is important. treatment treatment is aimed at removing the irritant or infection. helicobacter pylori infection is usually treated with antibiotics.