what is the word for checking out certain things with blood
A. A. A. When doctors test for fecal occult blood they are testing for the presence of microscopic or invisible blood in the stool, or feces. Fecal occult blood can be a sign of a problem in your digestive system, such as a growth, or polyp, or cancer in the colon or rectum. If microscopic blood is detected, it is important for your doctor to determine the source of bleeding to properly diagnose and treat the problem.