There are particularly many causes of blood in the stool in the elderly, and the color of the blood in the stool should be analyzed. If the blood in the stool is bright red, consider that the bleeding is closer to the anus. It may be a bleeding hemorrhoid, which is caused by swelling of the hemorrhoid nucleus and rupture of the hemorrhoid vein during difficult stools or increased abdominal pressure. It may also be an anal fissure, such as dry stool, where prolonged constipation can damage the skin of the anal canal causing a fissure, which leads to blood in the stool when wiping it. There may also be rectal polyps and rectal adenomas, both of which can cause bleeding from blood vessels in the rectal mucosa. If the blood in the stool is black in the elderly, upper gastrointestinal bleeding is considered, suggesting that the bleeding may also be distant from the anus. It may be a bleeding gastric ulcer or small intestine diverticulum, small intestine lesion, or a malignant tumor of the colon, which requires gastroscopy or colonoscopy to clarify the site and cause of the bleeding.