Bowel cancer blood in stool is generally persistent throughout the blood in stool, which can be mixed with blood in stool. Blood in stool is not necessarily caused by bowel cancer, but may also be caused by hemorrhoids, anal fissure, intestinal polyps and other diseases. Bowel cancer generally refers to colorectal cancer, which has no obvious symptoms in the early stage. When the cancerous lesion infiltrates the mucous membrane of the intestine, the local ulceration leads to tumor rupture, and then the symptom of blood in stool can occur. Since colorectum is the site of stool formation and storage, this kind of blood in stool is often mixed with blood, and the stool may appear jam-like dark red color, and the whole process will discharge blood in stool. First blood after the stool can be seen in patients with hemorrhoids, when these patients squatting, abdominal pressure rises, which can lead to hemorrhoids pressure increases rupture bleeding, the color of this blood is bright red, the surface of the stool can be stained with blood, stool will not be mixed with blood. Blood after stool can be seen in patients with anal fissure, this is due to the friction of feces on the anus caused by bleeding, so bleeding after stool, the color of this blood in stool is also bright red. If you have symptoms of blood in stool, you should consult a doctor to find out the cause and give treatment as soon as possible to avoid delaying your condition.