Black or Tarry Stools UF Health Hematochezia vs Melena: Symptoms, Causes, Diagnosis, Treatment Different stool colours can provide important clinical clues related to digestion, bleeding, liver disease, malabsorption, infection, or bowel inflammation. Disclaimer For educational purposes only. Not medical advice. Consult a qualified 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 Stool Colors and What They Can Tell You Your stool color can carry important clues about digestion, diet, or even disease. Most shades are harmless, but some changes signal the need for Melena Wikipedia