The digestive tract begins with the mouth and includes esophagus, stomach, small and large intestine, and ends at the anus. Bleeding may occur anywhere along this pathway and may be visible in vomit or in the stool. The bleeding can be slow and persistent causing anemia and black stools (melena) or fast and extensive resulting in bright red blood in the stool and dizziness. Rapid gastrointestinal bleeding can be a life threatening illness.