Anal fissures are the first thing to consider when there is pain in the anus during defecation. Anal fissures are chronic ulcers formed by rupture of the entire skin layer of the anal canal below the dentate line, which mainly manifests as anal pain after defecation, blood in the stool, and constipation. Anal fissures with a longer history are called old anal fissures and are associated with the anal fissure triad, which includes anal canal fissures, anterior sentinel hemorrhoids, and enlarged anal papillae. Anal fissures can occur at any age, but are most often seen in young adults. Treatment includes non-surgical treatment and surgical treatment. Non-surgical treatment includes dietary adjustment to increase the intake of fibrous foods such as vegetables and fruits to correct constipation; local sitz baths for the anus, which can be used with warm salt water or Chinese herbal medicine to promote fissure healing; oral medications such as paraffin oil and Fosamax to effectively soften the stool and relieve constipation; and topical medications such as tylenol suppositories for the anus or Puji hemorrhoids The anal dilation therapy is suitable for acute and chronic anal fissures that are not accompanied by enlarged anal papillae and sentinel hemorrhoids. If the above non-surgical treatment still cannot cure the fissure, surgical treatment should be considered, which can be performed by excision of the anal fissure plus partial severance of the internal anal sphincter.