a long, thin medical device that is used to examine the inside of the stomach

A special instrument called a gastroscope is put in the mouth and passed down into the stomach. 一个叫做胃镜的特殊工具从口腔置入，下行到胃部。

The gastroscope is fitted with a tiny camera that allows the doctor to see the stomach lining. 胃镜上装有一个微小的摄像机，让医生可以看到胃的内壁。