a medical examination of the inside of the stomach and part of the small intestine (= the upper part of the bowels between the stomach and the large intestine) using a gastroscope (= a long, thin medical device with a light and camera)

A gastroscopy showed duodenal ulcers. 通过胃镜检查发现有十二指肠溃疡。

The patients all underwent routine diagnostic gastroscopy. 所有患者都做了常规诊断性胃镜检查。