What causes bloody stool?
According to Kenneth McQuaid, M.D., chief of the gastroenterology section of San Francisco Veterans Administration Medical Center, the causes of bloody stool depend on how severe the bleeding is and your age. Even so, there are many potential causes. If you are younger than 50 years of age, the most common causes of bloody stool are inflammatory bowel disease and anorectal disease. If you are older, then the most common causes are diverticulosis, malignancy and vascular malformations.