Blood in your diarrhea may be the result of hemorrhoids, something you ate, or bleeding in the esophagus, stomach, small intestine or large intestine.
In an interview with MSNBC, Dr. Amy Foxx-Orenstein, president of the American College of Gastroenterology, said ʺ If there is bleeding higher up in the GI tract—like the stomach or esophagus—the result can be stool that looks black and tar-like. It’s very useful information for the doctor to know if what you’re seeing is black or bright red because that gives a clue to the location of the bleeding.”
Dr. Orenstein recommends contacting your doctor if you see blood in your stool and if you have the following symptoms:
• Diarrhea and cramping
• Weakness, lightheadedness, and dizziness
• Nausea or vomiting of blood
• Abdominal pain
Watery diarrhea may be a result of food rapidly passing through your system.
https://www.empowher.com/diarrhea/content/diarrhea-color-your-stool?page=0,1