Bowel cancer may cause different symptoms in the stool, such as thinning of stool, unformed stool, more frequent stool, and blood in the stool. Unshaped stool may be yellowish thin stool or paste-like stool, and the number of stools may increase significantly, such as 2-3 times a day or more, or the stool may be uncontrollable. Blood in stool mainly means that the surface of the patient’s intestinal tumor breaks down, resulting in the mixing of stool with blood. If the tumor is located high, it may be black stool, and if the tumor is located low, it may be bright red blood stool. In addition, it is possible that there is still bleeding in the anus after defecation. Therefore, if the patient’s stool is not normal, he needs to come to the hospital for examination. It is generally recommended to do colonoscopy directly to find out whether there is tumor inside the intestine.