Gastrointestinal bleeding is blood loss anywhere from the mouth to the anus. It is grouped into upper (proximal to the ligament of Treitz) and lower (distal to that point) sources, each with characteristic clinical pictures. Blood may be seen, hidden in stool, or detected only by laboratory tests; volume can range from trivial to rapidly fatal. Recognising the varied presentations guides location, pace, urgency of evaluation, and need for resuscitation. Visible upper-tract patterns• Hematemesis: vomiting red or clotted blood indicates brisk bleeding; coffee-ground material signifies slower gastric contact.• Melena: black, tarry, foul-smelling stool produced by ≥50 mL of upper-tract blood;... Learn more