Etiology of Upper and Lower Gastrointestinal Bleeding

Impact of Esophageal Varices and Portal Hypertension on Upper GI Bleeding

Gastrointestinal (GI) bleeding is a significant medical concern, categorized as either upper or lower GI bleeding. Upper GI bleeding typically originates from the esophagus, stomach, or duodenum, whereas lower GI bleeding stems from the small intestine, colon, or rectum.

Causes of Upper GI Bleeding

• Esophageal Varices: Dilated veins in the esophagus, commonly caused by portal hypertension, leading to massive hemorrhage.
• Peptic Ulcer Disease: Erosion in the stomach lining due to Helicobacter pylori infection or prolonged NSAID use.
• Gastritis: Inflammation of the gastric mucosa due to alcohol, medications, or infections.
• Mallory-Weiss Tears: Longitudinal lacerations in the esophagus resulting from severe vomiting.

Causes of Lower GI Bleeding

• Diverticulosis: Pouches in the colon susceptible to bleeding.
• Inflammatory Bowel Disease (IBD): Conditions such as Crohn’s disease and ulcerative colitis causing mucosal bleeding.
• Colon Polyps: Benign growths that may lead to bleeding if irritated.
• Hemorrhoids: Swollen veins in the rectum causing fresh blood in stools.

Esophageal Varices and Portal Hypertension

Esophageal varices are a critical cause of upper GI bleeding, stemming from elevated pressure in the portal vein due to liver cirrhosis. The rupture of these varices results in rapid blood loss, requiring emergency medical intervention.

Diagnosis and Management

Common diagnostic tools include endoscopy, colonoscopy, and imaging techniques like CT angiography. Management may involve proton pump inhibitors (PPIs), endoscopic interventions, and in severe cases, surgical procedures such as transjugular intrahepatic portosystemic shunt (TIPS).