由 THE GI TRACT Esophagus Above Treitz 's ligament 上消化道出血 Liver. Pancreas Below Treitz's ligament Gallbladder 中消化道出血 Large Intestine ileocecal valve Small Intestine 下消化道出血 Sigmoid Flexure e Rectum上消化道出血 下消化道出血 中消化道出血 2 Above Treitz ‘s ligament Below Treitz’s ligament Ileocecal valve