Illustration of an endoscopic examination, a gastroscopy: Via a camera, the mucosa of esophagus, stomach, and parts of the small intestine are examined. If necessary, a tissue sample can be extracted.
The camera tube (endoscope) is inserted via mouth and esophagus into the stomach, up to following parts of the small intestine. The procedure is about finding tissue changes like ulcers / cancer / (esophagal) varices.