Black stool (melena) indicates an upper GI source: esophagus, stomach, duodenum chiefly. But _any_ source of colonic bleeding is likely to be red to bright red

Black stool (melena) indicates an upper GI source: esophagus, stomach, duodenum chiefly. But _any_ source of colonic bleeding is likely to be red to bright red. The possible pathologies are numerous: hemorrhoidal - as you mention, tumours, inflammatory bowel disease, arteriovenous malformations, diverticular disease, etc.