The anal fissure triad generally refers to the triad of anal papilloma or anal papillitis, sentinel hemorrhoids, and old anal fissures or their resulting subcutaneous fistulas, which, in the case of anal fissures, would fall into the category of stage III anal fissures. Therefore, the anal fissure triad is a stage III anal fissure. It is usually caused by blood heat and intestinal dryness, constipation, and excessive straining to defecate, which ruptures the anal skin and causes repeated fissures. In the Jinjian of Medicine – Essentials of Surgical Technique, it is stated that “those who have their anus surrounded by folds and ruptures, and whose stool is constipated, are also hot and dry.” This briefly explains that constipation due to heat and intestinal dryness, or constipation due to yin deficiency and fluid deficiency, and straining to defecate, causes the anal skin to crack, followed by secondary infection, gradually forming a chronic, shuttle-shaped ulcer. However, the disease also develops due to infections such as anal canal stenosis, anal eczema, and hemorrhoid injury. Specifically, the occurrence of this disease is mainly related to the following factors: Pathogenetic factors 1. Anatomical factors: the superficial external anal sphincter, starting from the tailbone and going forward to the back of the anus. It is divided into two bundles, which surround the anal canal on both sides and then unite with each other in front of the anus. Therefore, there are gaps in the front and back of the anus. And most of the anal levator muscle is attached to both sides of the anal canal, less in front and behind. It can be seen that the anterior and posterior sides of the anus are not as strong as the sides and are easily damaged. And downward and backward form an angle of nearly 90 degrees with the rectum. Therefore, the posterior part of the anal canal is heavily compressed by feces, and because the posterior part of the anal canal has insufficient blood circulation, poor elasticity and more distribution of anal glands, these are the factors for the occurrence of anal fissure. 2, trauma theory: dry and hard stool or foreign bodies are likely to cause damage to the skin of the anal canal, which is the main factor causing anal fissure. 3.Infection theory: mainly the anal fossa in the back of the anus is infected and the inflammation spreads to the lower part of the skin of the anal canal, resulting in the subcutaneous abscess breaking and becoming anal fissure. 4, internal sphincter spasm theory: due to injury or inflammatory stimulation of the anal canal, the anal sphincter is in spasm, resulting in increased tension of the anal canal, which is easily damaged into anal fissure. 5, anal slit theory: the anal canal skin in the development of retarded, generate anal canal slit, easy to damage into anal fissure. The causes of anal fissures according to Chinese medicine The occurrence of anal fissures according to Chinese medicine is mostly caused by dry fire, damp heat in the anus and blood deficiency intestinal dryness. 1, feeling wind and fire, dry heat: dry fire in the stomach and intestines, burning fluid, hard and dry feces, difficult to discharge, strong nuisance and damage to the anus, resulting in fissures, fissures due to constipation and repeated deepening, long time not healed, resulting in anal fissures. 2, damp heat in the anus: external damp heat evil, internal accumulation of alcohol, wine, fat and sweet, resulting in damp heat in the gastrointestinal, down to the anal canker, canker ulcer does not heal and become anal fissure. 3, blood deficiency intestinal dryness: the elderly, postpartum and anemic patients, blood deficiency intestinal dryness for constipation, most likely to occur anal fissure.