Gastrobiopsy is an instrumental procedure in which a piece of tissue is taken from the surface of the mucous membrane of the stomach or duodenum for examination by endoscopy - gastroscopy. This is the gold standard option for taking a biopsy. Taking tissue samples during gastroscopy is possible only at body height - 15–16 cm from the esophageal entrance. Gastroscopy is not very informative in other areas. That is why it is much preferable to take a biopsy from the most diagnostically significant area of the mucous membrane using gastroduodenoscopy. Common to both techniques is the use of an endoscopic probe with a light source (endoscope) attached to it, as well as a manipulator, to visualize the mucosa. This technique has a wide range of indications, and is very rarely performed just to calm the patient down.