1, Gastroscopy and biopsy: Gastroscopy in combination with pathological examination of biopsy under direct vision is the main method for diagnosing chronic gastritis. Superficial gastritis is often most obvious in the antrum of stomach, mostly diffuse, and the change of gastric mucosa appears as a mixture of red and white or texture change. Sometimes scattered erosion can be seen, and there are commonly white or yellowish white exudates.