The formation of anal fissures may be related to chronic constipation. Constipation and dry stools that cause mechanical trauma to the anus during defecation are the direct cause of most anal fissures. In addition, some sexually transmitted diseases, such as syphilis and chlamydia, as well as anal canal cancer, may also cause anal fissures to appear, but are less common. The ligament at the back of the anal canal is less stretchable, has less blood supply, and is under great pressure during defecation, so anal fissures are more likely to develop and heal more slowly in this location. The common treatment can be divided into two categories: conservative treatment and surgical treatment: 1. Conservative treatment: 1. eat more fiber-rich vegetables and fruits to help digestion, and if necessary, take oral laxatives and stool softeners to relieve constipation; 2. take a hot water bath after defecation to keep the anus locally clean, and before bedtime or when the pain is severe, use topical creams or suppositories to relieve pain and spasm and promote fissure healing, such as diclofenac sodium suppositories, anti-hemorrhoid suppositories 3.Under local anesthesia, after dilating the anus with the index finger, slowly extend the two middle fingers or dilators to enlarge the wound surface, relieve spasm and promote healing. This method is suitable for patients with severe pain and fear of surgery, but it is easy to recur or cause infection. Surgical treatment: 1.Anal fissure excision: remove all the fissure edge and surrounding lesions, the excision is more extensive, not easy to recur but the trauma is larger and slower to heal; 2.Anal sphincter cut: after cutting the internal sphincter and surrounding anal papilla hypertrophy and other accompanying lesions, dilate and stop bleeding. The recovery is faster and the cure rate is high, but improper surgical methods may lead to postoperative incontinence; 3. Anal flap technique: for patients with chronic anal fissures, this surgical method is safer. It is more suitable for patients with large anal canal skin breakage and with obvious stenosis.