Melena: What Is It, Causes, Symptoms, Bleeding, Treatment, and More Osmosis Retroflexions.com The Rectal Bleeding Rainbow giftdistribution.blogg.se Gi bleed black stool GASTROINTESTINAL HEMORRHAGE (2): Melena. Melena, the passage of black, tarry stools, usually implies blood loss greater than 500 ml originating anywhere between the oropharynx and the right hemicolon. Melena occurs most often, Foods That Cause Dark Stools and When to Be Concerned GoodRx