The stomach can be seen through a flexible electronic endoscope. The endoscope can enter the human body through the natural orifice of the human body or through a small incision made by surgery. The original endoscopes were made of rigid tubes and were invented more than 100 years ago. Although they have gradually improved, they are still not widely used. Later, in the 1950s, flexible tube endoscopes were used, which allowed them to bend easily around the corners of the body. In 1965, Harold Hozenkins installed a cylindrical lens on an endoscope to make the field of view clearer. Today's endoscopes usually have two fiberglass tubes through which light enters the body. Doctors Observation is done through another tube or through a camera, and some endoscopes even have tiny integrated circuit sensors that feed back what is observed to a computer. This operation can be done with an endoscope and a laser. The optical fiber of the endoscope can deliver a laser beam to cauterize the growths or tumors, and seal the bleeding blood vessels.

Regarding the classification of medical endoscopes, according to their development and imaging structure, they can be roughly divided into three categories: rigid tube endoscopes, optical fiber (tube type) endoscopes and electronic endoscopes. There are many different types of endoscopes for medical examination, and their classification methods are different. Generally speaking, the following three classification methods are more common. In terms of market sales, the most used categories are currently divided into two types: rigid mirrors and flexible flexible mirrors.

According to the different parts reached by the endoscope, they are classified into neuroscopes, urethral cystoscopes, resectoscopes, laparoscopes, arthroscopes, sinusoscopes, laryngoscopes, etc.