gastrointestinal bleeding

Gastrointestinal bleeding is a common and serious clinical syndrome. The gastrointestinal tract refers to the passage from the esophagus to the anus, including the stomach, duodenum, jejunum, ileum, cecum, colon, and rectum. Upper gastrointestinal bleeding refers to bleeding from the esophagus, stomach, upper jejunum, pancreatic duct, and bile duct above the ligament of Treitz. Bleeding from the intestinal tract below the ligament of Treitz is called lower gastrointestinal bleeding. The clinical manifestations of gastrointestinal bleeding depend on the nature, location, amount of blood loss, and rate of bleeding, and are also related to the patient's age, cardiac and renal function, and other systemic conditions. Acute massive bleeding mostly presents as hematemesis; chronic small-volume bleeding manifests as positive fecal occult blood. When the bleeding site is above the Treitz ligament in the jejunum, the clinical manifestation is hematemesis. If blood is retained in the stomach for a prolonged period after bleeding, it becomes coffee-ground colored due to the action of gastric acid converting it to acid hematin. Foreign data show that patients with upper gastrointestinal bleeding account for approximately 0.1% of the average annual total hospital admissions, with a mortality rate close to 10%. There are currently no relevant domestic data. In clinical practice, lower gastrointestinal bleeding is less common than upper gastrointestinal bleeding, accounting for approximately 30% of all gastrointestinal bleeding. Foreign data show that patients with lower gastrointestinal bleeding account for approximately 0.02% of the average annual total hospital admissions, with a mortality rate of approximately 3.6%. Lower gastrointestinal bleeding is more common in elderly patients; the incidence in 80-year-olds is more than 200 times that in 20-year-olds.