The difference between bleeding before bowel movement and bleeding after bowel movement lies in the different causes and different sequences of defecation and bleeding, which need to be treated according to the causes. Bleeding before bowel movement is usually caused by gastrointestinal bleeding and other diseases, such as gastric ulcer, duodenal ulcer, ulcerative colitis and so on. Bleeding is caused by damage to the intestinal mucosa, and is often manifested as tarry stools, indicating that the patient has already had bleeding in the intestinal tract before bowel movement, and requires prompt medical attention and treatment after a clear diagnosis is made. Bleeding after defecation is usually caused by hemorrhoids, anal fissure and other diseases. Bleeding is caused by irritation of the rectal mucosa or anal stenosis during defecation, and is accompanied by anal pain, indicating that the patient has blood in the stool after defecation. It is recommended that patients should consult a doctor in time after finding blood in the stool, and then follow the doctor’s instructions to be treated accordingly after a clear diagnosis.