Right half colon cancer may have bloody stool (clinically known as blood in stool), which is related to whether its blood supply is rich or not, the progress of disease and whether it is treated in a standardized way. If the blood supply of right half colon is rich and the malignant tumor is large and fast growing, it is easy to invade blood vessels of tissues and cause bleeding, which is manifested as blood in stool, change of bowel habit and shape of stool. Blood in stool of right half colon cancer usually does not occur in the early stage, but usually occurs in the middle and late stage of cancer. When the tumor grows to a certain degree, its surface is not uniformly ischemic and necrotic, and then ulcerates and causes bleeding, and in serious cases, mucus-pus-blood stool with bright red or dark red color occurs. Once diagnosed with colon cancer, it is necessary to go to the hospital in time and actively cooperate with the treatment, so as to avoid delaying the condition.