Figure 1 .

Classification of chronic atrophic gastritis according to the location of the border between the fundic and pyloric gland regions by endoscopy: C1, at the angular part of the lesser curvature; C2, in the lower part of the lesser curvature; C3, in the middle part of the lesser curvature; O1, all parts of the lesser curvature are pyloric; O2, the stage between O1 and O3; O3, all mucosa of the stomach is non-acid-secreting.