Lower gastrointestinal bleeding

Lower gastrointestinal bleeding is defined as blood loss that originates from a source distal to the ligament of Treitz and results in hemodynamic instability or symptomatic anemia. The annual incidence of lower gastrointestinal bleeding is approximately 0.03% in the adult population as a whole, with a greater than 200-fold increase from the second to the eighth decade [1,2]. This rise in incidence with age may be explained by the increasing prevalence of colonic diverticulosis and colonic angiodysplasia with age. The mean age of patients with lower gastrointestinal bleeding ranges from 63 to 77 years, with a reported mortality rate of 2% to 4% (Table 1) [2-7]. Although approximately 10% to 15% of patients presenting with acute severe hematochezia have an upper gastrointestinal source of bleeding identified on upper endoscopy, the most common causes of lower gastrointestinal bleeding are diverticulosis, hemorrhoids, ischemic colitis, and angiodysplasia [4,8-10]. As with upper gastrointestinal bleeding, lower gastrointestinal bleeding ceases spontaneously in most cases. Fig. 1 is an algorithm that shows diagnosis and treatment options for the patient presenting with acute severe hematochezia.