Melaena Causes Diagnoses Management TeachMeSurgery Black stool? Bright red blood? Each tells a different story. I've explained what these signs indicate and when to seek help. Watch the video, and if you relate to any of these What Your Poop Says About Your Health Black, Green or Bloody: What's Up With My Poop? Diet vs Disease Foods That Cause Dark Stools and When to Be Concerned GoodRx