Chronic diarrhoea and fatty stools Abdominal Key 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 Approach to the child with acute diarrhea in resource limited settings UpToDate Dark stool vs black stool the difference can be serious. Dark brown stool is often food or iron related. Black, tarry stool may indicate internal bleeding and needs urgent medical attention.