The Quantity of Blood Required to Produce a Tarry Stool. How much? Melena, characterized by black tarry stools, can occur with as little as 50 cc of blood in the stomach. How Understanding Melena: What Does It Mean When You Have Dark Stools? Fortis Healthcare Nobody likes to talk about this. The color of your stool matters because it leaves behind clues on your digestive health. When digestion is working well, bile flows properly, fats are absorbed, What does your poop colour indicate? Pay attention. There's a lot to be learned by the colour and consistency of your stools, as well as the frequency and how easily passed What Does Clay Colored Stool Mean