What are the black, floating, small blueberry sized balls in my watery stools /diarrhea?

Black stools: Black fragments or balls in bowel movements may be from blood high up in the gastrointestinal tract, medications like iron supplements or peptobismol. Watery diarrhea may be from a viral gi infection, food poisoning or food intolerance, irritable bowel syndrome,inflammatory bowel disease,or certain medications. If black stools and diarrhea persist, see your physician for evaluation.