Although the development of modern medicine has helped us detect and treat diseases better than in the past, especially in the field of surgery; the history of medicine may be a trigger that can help us use neglected aspects of prior knowledge for the advancement of modern-day science. Since historical papers that have specifically focused on anorectal diseases are rare, but those that exist contain brief discussions in this field, the current study aims to present a detailed review of Avicenna's approach to anorectal diseases. Therefore, we reviewed On the Diseases of the Anus, the 17th chapter of the third volume of the Canon of Medicine written by Avicenna, and compared his views on the classification and diagnosis of, and the approach to anorectal diseases with that of modern proctology. Avicenna discussed in detail about anorectal diseases such as hemorrhoid, fissure, perianal abscess and fistula, rectal prolapse, fecal incontinence, and pruritus ani. In addition, we introduce herbs which Avicenna used to treat these diseases. Our findings show that Avicenna's views on the classification and diagnosis of, and the approach to anorectal diseases have few fundamental differences with modern medicine. In addition, the pharmacological effects of some of the herbs that were recommended by Avicenna, and are used in current medicine are proven. Thus the Medieval knowledge can be further scientifically investigated to develop new therapeutic options for anorectal diseases.