Anal pain during defecation may be caused by constipation, anal fissure, hemorrhoids, infection, tumor and other diseases. 1. Constipation: Various causes of irritation caused by dry stools cause constipation symptoms, hard stools to stimulate the anus, may lead to anal pain during defecation. 2. Anal fissure: small ulcers caused by cracks in the skin layer of the anal canal below the dentate line, which can also lead to anal pain during defecation. 3. Hemorrhoids: and the anus local vascular varicose veins and arterial venous anastomosis abnormality and other reasons, hemorrhoidal core congestion and edema accompanied by inflammation, may also cause anal pain in defecation. 4. Infection: Infectious diseases of anus or rectum, such as perianal abscess, sinusitis, etc. can also cause anal pain in defecation. 5. Tumor: benign and malignant tumors of anus and rectum may also cause anal pain. There may be other reasons for anal pain, the cause is complex, it is recommended to go to the hospital in time for a detailed examination, to clarify the cause of the disease and follow the doctor’s instructions for active treatment.