Approaching the patient with chronic malabsorption syndrome.

The causes of chronic malabsorption may be categorized as decreased intestinal absorption, most commonly caused by celiac sprue; or maldigestion caused by pancreatic insufficiency. The initial step in the evaluation of these patients should include stool studies to confirm fat malabsorption. If fat malabsorption is confirmed, endoscopy with small-bowel biopsies and aspirates for bacterial culture usually follows. A normal endoscopic examination should lead to assessment of pancreatic function. In the setting of normal pancreatic function and the absence of bile acid deficiency, a barium radiograph of the small bowel should be made, looking for anatomical abnormalities. Celiac sprue is an intolerance to gluten caused by a combination of genetic, environmental, and immunologic factors. It classically causes malabsorption. However, it is likely that many patients who exhibit only minor manifestations of the disease go unrecognized and untreated. A presumed diagnosis of celiac sprue is confirmed after a clinical and endoscopic response to a gluten-free diet. Serological markers are available with high degrees of sensitivity and specificity, but duodenal biopsy remains the gold standard for diagnosis. A minority of patients are unresponsive to a gluten-free diet, and intestinal lymphoma should be suspected in these cases.