An endoscope is a thin, flexible, lighted viewing instrument. It is used during procedures to examine the inside of organs, canals, and cavities in the body.

An endoscope may be inserted into a person's mouth and guided down the throat to examine the esophagus, stomach, and upper end of the small intestine. Different types of endoscopes can also be used to study the sinuses, the colon, the uterus, and other parts of the body.