A d-xylose test was requested on a patient with history of long standing steatorrhea '5' hour urine sample showed <4.0 gm excretion after giving 25 gm of d-xylose. The most likely diagnosis is :

Answer is D (Celiac sprue) A Positive d-xylose test suggests a diagnosis of celiac disease Decreased urinary excretion of d- xylose (<5.0 gm) 5 hours after administration of 25 gm D- xylose (positive test) suggests malabsorption due to intestinal mucosal disease in the proximal small bowel (duodenum and jejunum). Celiac disease is a charachteristic cause for positive d-xylose test and the single best answer amongst the options provided Modestly abnormal d-xylase test may also be seen in cases of bacterial overgrowth syndrome, however patients with bacterial overgrowth syndrome may also have normal d-xylose excretion, and hence this is not considered as the most likely diagnosis D-Xylose Test Schilling Test Duodenal Mucosal Biopsy Chronic pancreatitis Normal 50% abnormal; if abnormal, normal with pancreatic enzymes Normal Bacterial overgrowth syndrome Normal or only modestly abnormal Often abnormal; if abnormal, normal after antibiotics Usually normal Ileal disease Normal Abnormal Normal Celiac sprue Decreased Normal Abnormal: probably "flat" Intestinal lymphangiectasia Normal Normal Abnormal: "dilated lymphatics"