Locked hemorrhoid is a diagnosis in Chinese medicine, which is called rectal cancer in Western medicine. The main symptoms of rectal cancer include the following: 1. Blood in stool. Blood in stool is the earliest symptom of rectal cancer, a small amount of blood in stool can not be detected by naked eyes, but only accidentally discovered during stool occult blood test, and when the amount of bleeding is large, blood in stool can be seen, some of which are bright red in color and some are dark red. 2. Change in stool habit. Change in stool habit is also a relatively early symptom, mainly manifested as constipation or increased frequency of stool, or both alternately. 3. Mucus stool or pus and blood stool. Almost all patients with rectal cancer are not just having bloody stools when they develop to a certain extent, but will have different degrees of mucus or pus in the blood. 4. Change of stool shape. When the rectal tumor is large to a certain extent, it may cause a change in the shape of stool during the process of discharge.