Understanding melena: when black stool signals upper digestive tract bleeding

Black, tar-like stool, known as melena, can indicate bleeding in the upper digestive tract. While diet or medications can cause dark stools, persistent melena, especially if sticky and foul-smelling, requires medical evaluation to rule out serious causes like ulcers or gastritis. Symptoms can include weakness and dizziness, and diagnosis often involves stool tests and endoscopy, with treatment varying based on the underlying cause.