It is difficult to determine whether there is blood in the stool, and it is recommended to go to the hospital for laboratory tests, such as fecal routine, fecal occult blood, etc. The doctor will diagnose whether there is blood in the stool through the test results. Blood in stool is mainly manifested as bright red, dark red or tarry black feces, and when the patient wipes the anus, there is red liquid or mucus. Blood in stool is a clinical symptom, and there are many diseases that cause this symptom, such as gastrointestinal bleeding, hemorrhoids, anal fissure, rectal cancer and so on. It is difficult for people’s eyes to distinguish the color and nature of blood in stool. It is recommended to make a clear diagnosis through specimen examination or luminal examination, and take appropriate treatment measures according to the diagnosis, and perform surgical treatment if necessary.