Simple fecal tests of absorption. A prospective study and critique

A prospective study in which the value of four stool screening tests of malabsorption was assessed demonstrated that the Sudan stain for fat, with or without heat and acid, microscopic search for meat fibers and radiotriolein excretion, but not the gelatin film tests, was accurate in 69–79% of studies. Accuracy was lowest in mild steatorrhea and because of this, screening tests were least helpful in patients in whom these tests might have realized their greatest potential value for clinical diagnosis. With high meat intake, stool meal fibers proved as good as, or better than, the other methods for testing for nonspecific malabsorption. The gelatin film test, stool meat fibers and the differential results of the Sudan test before and after heat and acid were of no specific value in distinguishing patients with pancreatic insufficiency from those with other causes of malabsorption; their use for this purpose should be abandoned.