Obscure overt gastrointestinal bleeding: a review

Obscure-overt gastrointestinal bleeding 1 of upper GI bleeding most commonly includes peptic ulcer, esophageal and gastric varices, Mallory-Weiss tear, and Dieulafoy lesions, while lower GI bleeding is most commonly due to diverticulosis, hemorrhoids, angioectasia, colitis, and neoplasms. 3,4The differential diagnosis of OGIB can be stratified based on the patient's age.For example, in patients younger than 40 years, OGIB is more likely to be due to malignancy (eg, lymphoma), polyposis syndromes, Meckel's diverticulum, inflammatory bowel disease, or Dieulafoy lesions. 1 In older patients (≥40 years), OGIB is more often caused by angioectasias or a nonsteroidal anti -inflammatory drug (NSAID)-induced ulcer.The most common causes of OGIB are summarized in TAbLE 1 and described in more detail below.Angioectasia Angioectasia is the formation of aberrant blood vessels found throughout the GI tract that can develop in advanced age or as a consequence of related comorbidities (eg, chronic renal disease, cirrhosis, rheumatologic disorders, and severe cardiovascular disease).These lesions can cause overt or occult GI bleeding in adults, particularly in the elderly, especially in those treated with antiplatelet agents and / or anticoagulants.Angioectasias may involve any segment of the GI tract, and the lesions are usually multiple in any given segment of the intestine.On Introduction Gastrointestinal (GI) bleeding may originate anywhere from the mouth to the rectum or anus.Overt clinical manifestations of GI bleeding include hematemesis, melena, and / or hematochezia.Approximately 50% of the GI bleeding episodes originate in the upper GI tract (esophagus, stomach, and / or duodenum-proximal to the ligament of Treitz), 40% are from the lower GI tract (colon and rectum), and 10% are from the small bowel.Small bowel bleeding is defined as a bleeding that starts anywhere between the ligament of Treitz and the ileocecal valve. 1,2Obscure GI bleeding (OGIB) is defined as small bowel bleeding of unknown etiology after negative endoscopic evaluation including esophagogastroduodenoscopy (EGD) and colonoscopy with endoscopic evaluation of the terminal ileum.The presentation of OGIB may be either overt or occult.Obscure -overt GI bleeding refers to persistent or recurrent visible GI bleeding (eg, melena and / or hematochezia, and rarely hematemesis), while obscure -occult GI bleeding is characterized by persistently positive results of fecal occult blood tests, iron deficiency anemia, or both, without evidence of visible GI bleeding.This review focuses exclusively on the overt presentation of OGIB. Causes of obscure-overt gastrointestinal bleedingThe etiologies of upper and lower GI bleeding can be diagnosed and treated by EGD and colonoscopy, respectively.The differential diagnosis