[Chronic gastrointestinal bleeding].

Chronic gastrointestinal bleeding can occur as recurrent overt blood loss (hematochezia, melena or hematemesis) or as occult gastrointestinal bleeding. Occult bleeding from the gastrointestinal tract is typically identified by either a positive stool test for occult blood or by the presence of iron deficiency anemia. The major cause of iron deficiency anemia is blood loss from the gastrointestinal tract. In women, menstrual blood loss must also be considered. Approximately 5% of all patients with gastrointestinal bleeding do not have lesions identified by upper or lower endoscopy. In most of these patients, the bleeding source responsible for the chronic blood loss is located in the small bowel. The most common cause for gastrointestinal bleeding of small bowel origin is angiodysplasia, tumors of the small intestine (primary benign or malignant tumors or metastatic lesions) and various other causes (such as ulcers caused by nonsteroidal antiinflammatory drugs, aortoenteric fistula, diverticula, endometriosis and hemobilia). After negative upper and lower endoscopy, examination of the small bowel is warranted. Methods to evaluate the small bowel include enteroscopy, capsule endoscopy, small bowel radiographic studies and angiography. The role of each examination depends upon the clinical setting and available expertise. Explorative surgery with intraoperative enteroscopy is generally reserved for patients with ongoing transfusion requirement and in those under the age of 5O years (to rule out a small bowel neoplasm). This article reviews the concepts of evaluation and care of patients with chronic gastrointestinal bleeding.