A Comparison of Laboratory Tests in the Malabsorption Syndrome

Absorption of radioiodinated triolein was tested in 93 individuals (15 controls, 28 cases of functional diarrhea, and 50 patients with suspected or manifest malabsorption syndrome).The results so obtained were compared in 59 cases with estimations of fecal radioactivity and chemically determined fecalfat excretion. A highly significant correlation was found.The urinary xylose excretion test was performed in 96 individuals. The diagnostic value of the radioactive fat absorption test was compared with that of the xylose excretion test in 78 cases. Both tests were diagnostic in cases of non-tropical sprue, but the xylose excretion test reflected the clinical improvement more accurately in treated cases. The radioactive fat absorption test was more reliable in the diagnosis of malabsorption secondary to bowel resection than was the xylose excretion test, but the converse was true in the diagnosis of malabsorption secondary to gastrectomy. The simultaneous use of these two tests was found to be a simple and reliable screening procedure.