An endoscope is a doctor's tool for looking inside the body. It is a thin tube with a very small camera and a strong lens. Pictures go back to a screen, so the doctor can see what is happening without making a large cut. One common picture of it is a camera pushed through a tiny hole during an operation — for example on a joint or the belly. Though actually, doctors also pass an endoscope through the mouth, the nose, or another opening that is already there, to look at the stomach or the bowel. Ordinary people often just say they are "having a camera put down" or they name the test; endoscope is the precise hospital word for the instrument itself.