Drug treatment: 1. stool softening, solvent-based laxatives, high-fiber diet, sitz baths. 2.External treatment:Fumigation: applicable to all stages of anal fissure. It mainly has the function of activating blood circulation and removing blood stasis, reducing swelling and relieving pain. Commonly used formulas include Bitter Ginseng Soup and Exorcism Soup. Compress: Applicable to all stages of anal fissure. It has the function of clearing heat and detoxification, relieving pain and stopping bleeding. Commonly used ones are Yuhong Paste, Jiuhua Paste, etc. Plugging medicine: applicable to all stages of anal fissures. It has the function of clearing heat and detoxifying, relieving swelling and pain, and stopping bleeding. 3.Nitroglycerin for external use: nitric acid produced by nitroglycerin plays a relaxing role on the sphincter. 4.Closure therapy is suitable for old anal fissures with obvious pain. 5.Botulinum toxin injection. Surgical treatment: Applicable to old anal fissures or early anal fissures for which non-surgical treatment is ineffective. 1.Anal expansion method: Applicable to early anal fissures without comorbidities such as connective tissue external hemorrhoids and papillary hypertrophy. 2.Sphincter lateral excision method: applicable to early anal fissure without comorbidities such as external hemorrhoids, papillary hypertrophy, subcutaneous fistula and fresh fissures. 3.Anal fissure excision therapy: Applicable to old anal fissures with connective tissue external hemorrhoids, papillary hypertrophy, etc. Longitudinal incision and transverse suture method Suitable for old anal fissure with anal canal stenosis.