Blood dripping from the anus after stool but not painful may be due to the following three reasons: 1. It may be internal hemorrhoids, blood in the stool is the main symptom of internal hemorrhoids, because internal hemorrhoids occur in the rectal mucosal area above the tooth line and are innervated by the vegetative nerve, which is a painless nerve, so there is no pain. The mucous membrane of the hemorrhoid nucleus is very thin and is very susceptible to bleeding from stool abrasion, so internal hemorrhoids bleed without pain; 2. It may be a rectal polyp. Some rectal polyps will have the symptom of blood in the stool, the polyp will fall off or the mucous membrane will break down and there will be dripping blood with less blood and no pain; 3. It may be early rectal cancer, early rectal cancer blood in the stool can be painless, especially for older patients, those who have blood in the stool gradually worsen should be examined in time to exclude the possibility of tumor.