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 Melena vs hematochezia symptoms and differences There are no 50 shades of melena, only one color: Black; and it's a color that smells bad. Otherwise it's not melena or it's derivatives (melenic, melanotic, melenatonic ) Great thread w a 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