Human Phenotype Ontology identifier HP_0004398 (Peptic ulcer) can be described as follows. The term peptic ulcer refers to acid peptic injury of the digestive tract, resulting in mucosal break reaching the submucosa. Peptic ulcers are usually located in the stomach or proximal duodenum, but they can also be found in the esophagus or Meckel's diverticulum. Infection with Helicobacter pylori and the use of non steroidal antiinflammatory drugs (NSAIDs) or aspirin are the main risk factors of both gastric and duodenal peptic ulcers. Also known as: Sore in the lining of gastrointestinal tract.