Stool Reducing Substance is a test used to detect the unabsorbed sugar in the stool. Sugars

like fructose, glucose, lactose, and galactose can be identified in the stool sample with this

test.The sensitivities for stool reducing sugars and stool pH were 9% to 28% and specificities

were 74% to 81% for individual disaccharidase deficiencies. Infants (0 years of age) had the

highest percentage of abnormal results across all three tests; however, the positive

predicative values were 54% and 50% for stool reducing sugars and stool pH, respectively.