Whether or not an anal fissure that appears to bleed in the stool but is not painful heals on its own is related to the length of time the fissure has existed and needs to be analyzed on a case-by-case basis. Anal fissures are ruptures and tears in the skin of the anal canal, which usually manifest as blood in the stool, which is bright red but not in large amounts, mostly attached to the surface of the stool or present on toilet paper when wiping the anus. If the fissure is short, less than one month old, it is a fresh fissure and can usually heal itself by paying attention to diet and warm water baths. However, if the fissure is older than one month, it is called old anal fissure. Stage II and III old anal fissures are sometimes combined with sentinel hemorrhoids and subcutaneous fistulas, and such cases are usually less likely to heal on their own and need to be treated surgically. Therefore, when patients have bleeding during stool with constipation and anal itching, they should go to the anorectal department of the hospital for relevant examination and cooperate with the doctor for symptomatic treatment. In daily life, pay attention to keeping the bowels open, develop the habit of regular bowel movements, eat a light diet, eat more food rich in dietary fiber, and forbid spicy and stimulating foods.