Blood in the stool may require a colonoscopy. Blood in the stool may be caused by hemorrhoids, peptic ulcers, digestive tract tumors, etc. A colonoscopy can clarify whether there is any digestive tract disease. Blood in the stool, first check whether it is occasionally, or many times, and then look at the amount of bleeding, if it is occasionally and the amount of observation can be small, if it is a number of times or the amount of bleeding need to go to the hospital to improve the relevant examination. First of all, you need to improve the rectal diagnosis, rectal diagnosis is the simplest and most convenient method of examination. Then you need to improve the abdominal ultrasound, abdominal CT and so on. Blood in the stool also need to improve the gastroenteroscopy, because gastroenteroscopy can clearly see the situation inside the gastrointestinal tract, whether there are ulcers, polyps, tumors and other lesions, and even take a piece of tissue biopsy, clear pathology typing. Therefore, whether blood in the stool needs to improve the colonoscopy should be decided under the evaluation of a professional doctor.