Melaena Causes Diagnoses Management TeachMeSurgery A change in the colour of one's stools may sometimes be due to dietary changes; though it could also reveal something about one's health. Where stool appears or , it What Does The Color Of Your Stool Tell You Black, tarry stools are NOT normal. They could be a sign of Melena upper gastrointestinal bleeding that requires urgent medical attention. Learn the difference between Melena vs Hematochezia, common