Evaluation of the gastrointestinal tract in patients with iron-deficiency anemia

Idiopathic iron-deficiency anemia in adults is assumed to be the result of occult chronic blood loss from the gastrointestinal tract. The aim of this study was to determine an effective clinical strategy for managing this common clinical problem.

We prospectively studied 100 consecutive patients with iron-deficiency anemia, using colonoscopy and esophagogastroduodenoscopy and, in patients with negative endoscopic studies, enteroclysis (radio-graphic examination of the small intestine).

Gastrointestinal endoscopy revealed at least one lesion potentially responsible for blood loss in 62 of the 100 patients. Endoscopic examination of the upper gastrointestinal tract showed a bleeding source in 36 patients, and colonoscopy showed a lesion in 25; 1 patient had lesions in both the upper and lower gastrointestinal tracts. The most common abnormality in the upper gastrointestinal tract was peptic ulceration (duodenal ulcer in 11 patients, gastric ulcer in 5, and anastomotic ulcer in 3). Cancers, detected in 11 patients, were the most common colonic lesions. Enteroclysis was performed in 26 of the 38 patients with negative endoscopic studies, and the results were normal in all instances. Symptoms at a specific site in the gastrointestinal tract were predictive of disease in the corresponding portion of the bowel. In addition, the combination of positive tests for fecal occult blood and symptoms in the lower gastrointestinal tract had a positive predictive value of 86 percent for detecting a lesion in the lower gastrointestinal tract.

Gastrointestinal lesions (in both the upper gastrointestinal tract and the colon) are frequently found in patients with iron-deficiency anemia. Since site-specific symptoms are predictive of abnormalities in the corresponding portion of the bowel, the initial evaluation should be directed by the location of the symptoms. Concomitant lesions of the upper and lower gastrointestinal tract are rare; thus, detection of a likely source of blood loss during the initial examination may obviate the need for further procedures.