What does it mean if there is blood in my stool?

Bunch of things C MD. Visible blood in the stool can be from hemorrhoids, inflammation, polyps, diverticulosis (pockets in wall), fragile blood vessels, poor blood flow to bowel; uncommonly from higher up in the gut (major bleed). Occult (not visible, but chem tested +), can be all of the above plus other causes. See your doc to find out what and where it is from.
Any # of things. All of which your doctor can help you with! blood in the stool can range from hemorrhoids to inflammatory bowel disease to cancer to many other things. The history and a physical exam are critical here. I would ask your doctor to help you figure out what to do next!