According to Wikipedia:
Endoscopy means looking inside and typically refers to looking inside the body for medical reasons using an endoscope, an instrument used to examine the interior of a hollow organ or cavity of the body. Unlike most other medical imaging devices, endoscopes are inserted directly into the organ. Endoscopy can also refer to using a borescope in technical situations where direct line of-sight observation is not feasible.
Endoscopy has different uses. In can be done in gastrointestinal tract (GI tract) examination. This nonsurgical method is being used to check a person’s digestive tract with the use of an endoscope – a flexible pipe with a light and camera attached. The images captured by the camera of your digestive tract is being transmitted and viewed on a monitor. But once the procedure is set to the small intestine, it is then called enteroscopy.