The subject of this treatise, written in English, is the illustrated differential diagnosis of endoscopic findings. Its focal point is 221 full-color prints, accompanied by detailed captions, from leading international specialists. Conditions with similar appearances are presented and distinguishing endoscopic features pointed out. While the text focuses on four main topics, the pictures document various aspects of inflammations, ulcers and tumors, covering the majority of situations found in endoscopic practice.