Anal fissure is a pyknotic or oval rupture of the migrating epithelium of the anal canal below the dentate line caused by various reasons. It often presents with anal pain and bleeding after stool in small amounts, but if the fissure is at a blood vessel, bleeding will be more, bright red in color, constipation, and anal itching. The most common cause of anal fissures is the abnormal nature of the stool, such as constipation or diarrhea, and constipation is the cause of anal fissures and the result of anal fissures, both of which are causal, forming a vicious circle. Constipation leads to anal fissures, and the painful defecation caused by anal fissures aggravates constipation, which further leads to the deterioration and progress of anal fissures. The cycle continues, making it impossible to relieve the disease and eventually resulting in old, poke-shaped ulcer wounds. Therefore, anal fissures are divided into two stages: Stage I fissures: early stage fissures with fresh, shallow surface and no chronic ulcers, and less pain. Stage II fissures: Due to repeated attacks of fissures, the fissures form pyknotic or oval ulcers and are often complicated by fissured hemorrhoids, anal cryptitis, anal papillomegaly, and periodic pain. Therefore, the treatment should be according to different periods. For example, in the early stage, attention should be paid to adjust the soft and smooth stool and keep good local hygiene of the anal wound so that the fresh wound is not polluted and has sufficient time to grow. Because anal fissures expose local sensory nerve endings to external stimulation, they cause severe pain, while radioactively causing spasm of the anal sphincter, which affects the healing of anal fissures. In case of repeated attacks, the inflammatory stimulation of anal fissure causes thickening of the ganglion band and adhesion to the sphincter, which affects the diastole of the internal sphincter and causes spasm, producing difficulty in defecation, and so on and so forth, making the disease unrelieved. At this time, part of the internal sphincter should be cut off surgically (cutting off the internal sphincter will not cause fecal incontinence), which can release spasm.