The epidemiology and the nosology of obscure gastrointestinal bleeding

Obscure gastrointestinal bleeding is defined as persistent and recurrent gastrointestinal bleeding, the etiology of which remains unspecified after a first standard evaluation (upper endoscopy, colonoscopy and small intestine specific radiological investigations). This pathology is both a diagnosis challenge (due to the limited possibilities of endoscopic techniques usual imagistics to properly view the small intestine) and a therapeutic challenge (because of the associated morbidity and mortality), implying a higher consumption of health resources (it requires successive hospitalizations, expensive investigations and repeated transfusions). Most commonly, the bleeding headquarters is located in the small intestine and it is represented by vascular lesions (angiodysplasias), along with inflammatory bowel diseases, tumors and lesions induced by drugs (NSAIDs). In recent years, we have developed advanced diagnosis techniques (Video capsule endoscopy, double-balloon enteroscopy and enterography CT), which had led to a better understanding of the etiologic profile of the obscure gastrointestinal bleeding, allowing the establishment of specific and effective therapies.