Sore anus after stool may be related to perianal diseases, such as hemorrhoids, perianal polyps, intestinal malignant tumors and other diseases caused. 1. Hemorrhoids: due to constipation, poor defecation habits, sedentary and other factors triggered, internal hemorrhoids will appear in the defecation, there will be obvious swelling, and there will be corresponding symptoms of discomfort, need to go to the hospital general surgery or anorectal surgery for a clear diagnosis. 2. Perianal polyps: the growth of polyps will affect defecation, while there will be blood in the stool, intestinal irritation and other symptoms. 3. Malignant tumor of intestinal tract: such as rectal cancer, etc., need to check the colonoscopy and other clear diagnosis. It is recommended to develop the habit of regular defecation to prevent constipation. Eat more vegetables and fruits, abstain from alcohol and avoid spicy food. If the abnormal sensation in the perianal area is related to polyps, tumor disease, etc., it should be treated actively to avoid delaying the aggravation of the condition.