How long it takes for an anal fissure to heal depends on the period of the fissure lesion. Early anal fissures can heal in about 7-10 days after standard treatment, while old anal fissures require surgery and take about 1 month to heal completely. Anal fissure is an ulcerative wound on the anal sphincter, and patients clinically present with severe pain during defecation and a small amount of bleeding from the anus. For early anal fissures, conservative treatment is mainly adopted, and usually 7-10 can heal. For old anal fissures, the main treatment is surgery, which requires hospitalization for about 3-7 days after surgery, and it takes about 1 month for the wound to heal completely, but most patients can start their daily study and work in about 2 weeks after surgery. In addition, patients with anal fissures should pay attention to a light diet, eat more fresh fruits, vegetables and other fiber-rich foods, keep the bowels open, keep the perianal area clean after the stool, and standardize the change of medication after surgery, so as to promote wound recovery.