[Gastric ulcer and duodenal ulcer].

Peptic ulcer diseases are improved by strong acid suppression therapy. However, peptic ulcer diseases are often relapsed after discontinuing of acid suppression therapy. After discovery of Helicobacter pylori (H. pylori) in 1984, H. pylori is known as the strongest causal agent for peptic ulcer diseases. In November 2000, eradication therapy for H. pylori infection was approved under the Japanese system of health insurance. H. pylori eradication reduces ulcer recurrence dramatically. Recently, peptic ulcer diseases induced by NSAIDs and/or aspirin are increasing. In prevention of NSAIDs and/or aspirin induced peptic ulcer recurrence, H. pylori eradication plus PPI treatment is recommended. Several reports described occurrence of newly-developed gastric cancer after H. pylori eradication. Careful follow-up upper gastrointestinal endoscopy is necessary after H. pylori eradication.