Abstract
Since the discovery of Helicobacter pylori, the concept of diagnosis and treatment of upper gastrointestinal diseases has changed greatly from conventional beliefs. It has been recognized that H. pylori infection affects endoscopy images of gastric mucosa at the same time. It has been shown that development of chronic atrophic gastritis traditionally considered to be ageing phenomenon is noted in only subjects with H. pylori infection, and it has become clear that eradication of H. pylori markedly improved histological gastritis induced by H. pylori infection. It is also known that there is deep association between H. pylori infection and the background gastric mucosa which various disease is easy to develop of upper gastrointestinal diseases like gastric cancer. Since the histological change concerning H. pylori infection is reflected for the endoscope image, it is important to understand the characteristics of endoscopic findings in various infection status. When a risk of the gastric cancer is considered, it becomes important to grasp features of endoscope image in the 4 groups (uninfected, infected at present, infected in a past, and after eradication by treatment).
