Lactose IntoleranceLactaseMalabsorption SyndromesLactose Tolerance TestLactoseFlatulenceBreath TestsDairy ProductsHydrogenLactase-Phlorizin HydrolaseMilkKwashiorkorAbdominal PainCalcium, DietaryNational Institute of Mental Health (U.S.)Glucose IntoleranceDiarrheaIntestine, SmallFructose IntoleranceSprue, TropicalIrritable Bowel SyndromeIntestinal Absorptionbeta-GalactosidaseFecesSchilling TestCeliac DiseaseIntrinsic Factor