ORAL ABSORPTION TESTS - ABSORPTION SITE OF EACH SUBSTRATE

Three oral absorption tests have been used in patients with short bowe l syndrome (SBS) to evaluate the absorption site of each substrate. In this study, three absorption tests were applied: the oral pancreatic function test using N-benzoyl-L-tyrosyl-p-aminobenzoic acid (NBT-PABA) , the D-xylose tolerance test, and the oral fat tolerance test. Examin ations were performed in eight patients with either a duodenostomy or a jejunostomy located less than 60 cm from the ligament of Treitz, and in a patient with an end ileostomy. Forty-six healthy volunteers part icipated as controls for the oral fat tolerance test. PABA and D-xylos e concentrations were measured in urine. The serum triacylglycerol con centration was determined at 0, 1, 2, and 3 h after ingestion. All eig ht patients with SBS demonstrated pathologic absorption on each test. We conclude that small bowel integrity is critical for evaluation of t he NBT-PABA test. We also determined that the duodenum and proximal je junum do not play an important role in the absorption of D-xylose and triacylgylcerol. We could also evaluate limitations and advantages of the other kinds of oral absorption tests and nutrients through patient s with SBS. (C) Elsevier Science Inc. 1998.