There are more classifications of anal diseases, and there are different divisions of classification and their diseases. Specifically, they can be divided as follows: 1. according to the nature of the disease: malignant diseases including anorectal cancer, etc., and more benign diseases including common hemorrhoids, anal fissures, perianal abscesses, etc.; 2. according to organic and functional lesions: organic lesions including hemorrhoids, anal fissures, abscesses, etc., and functional lesions including sensory disorders, such as anal itching, and defecation dysfunction, i.e. puborectal muscle syndrome, and pelvic floor spasm Diseases, also called functional anorectal diseases, belong to a kind of perianal diseases.