This textbook consists of two parts. The first part includes 8 chapters on the General Science of Proctology, introducing the relevant information on the embryology, anatomy, physiology, pathophysiology and surgery of colon, rectum and anus and also their microbiology and immunology. The second part includes 20 chapters and explains the concrete diseases, clinical syptoms, root causes, types and stages, diagnosis and treatment, prevention and care of proctology. It has laid emphasis on the feature of Chinese medicine, clinical experience, and the recent advances of both Chinese and western medicine.