The book contains the author's original views on the problem of peptic ulcer of the stomach and duodenum. On the topic, the results of experimental and clinical studies in this area are summarized and logically interpreted. The author conducted interesting experimental and clinical studies, the results of which make it possible to revise the pathogenesis of peptic ulcer disease in a new way. M. Eshbekov proposes a new theory of ulcerogenesis, an almost convenient classification of the disease.