Stool bleeding bright red, painless may be internal hemorrhoids, rectal tumors. 1. Internal hemorrhoids: internal hemorrhoids are formed by varicose masses of venous plexus on the rectum. The main clinical manifestations of internal hemorrhoids are bleeding and prolapse. Fresh blood after intermittent bowel movements is a common symptom. In the absence of thrombosis, incarceration, infection, internal hemorrhoids are painless. Rectal examination of internal hemorrhoids can not touch the obvious mass. 2. Rectal tumor: Rectal tumor is most common in the lower rectum. Early rectal cancer has no obvious symptom, but when the tumor breaks down and bleeds, there may be blood in the stool. When the tumor breaks and bleeds, there may be blood in the stool. At the same time, there will be changes in defecation habit and stool character in the case of rectal cancer. There may also be rectal irritation sign, in which the patient feels uncomfortable in lower abdomen, wants to relieve stool very much, and has a feeling of incomplete defecation after defecation. Rectal fingerprinting may detect an uneven mass. Since painless blood in stool can be benign and malignant, so in order to avoid missing malignant diseases and delaying treatment, it is recommended that the patient should consult the doctor in time, and under the arrangement of the specialist, complete the detailed examination to exclude malignant diseases, and at the same time, take reasonable treatment measures as early as possible.