The blood in the stool is not painful and may be caused by the following diseases: 1, internal hemorrhoids, blood in the stool is the main symptom of internal hemorrhoids, defecation can cause bleeding or blood dripping after the stool, jet-like bleeding, bright red color without blood clots, blood and stool do not mix, no pain, bleeding is mostly a small amount, but bleeding more can cause anemia, deficiency symptoms. 2, rectal polyps, can be different degrees of blood in the stool, the amount of bleeding is not much, the blood is more red often over the surface of the stool, sometimes the stool has grooves, bleeding more can be directly stool fresh blood or blood clots, no pain, painless in childhood, rectal polyps to rectal polyps more, no pain. The blood is often over the surface of the feces, sometimes there are grooves in the feces, more bleeding can be direct blood or blood clots, there are also blood drops in the stool, no pain, painless blood in the stool in childhood is more common in rectal polyps. 3, early rectal cancer, early symptoms of blood in the stool, dark red blood, no pain, increased frequency of stool with a feeling of falling, constipation and diarrhea alternately, mostly seen in the middle-aged and elderly.