Illustration of an endoscopic examination (endoscopy) on the right: The intestinal mucosa is evaluated via a camera, and, if necessary, a tissue sample is taken (biopsy). Gastroscopy on the left: The mucosa of the esophagus, stomach, and parts of the small intestine is evaluated via a camera. The tube of the camera (endoscope) is, as shown here, inserted into the anus or the mouth. The examination can clarify tissue changes like ulcers or cancer. In Germany it`s offered as a preventive check-up.