LactaseLactose IntoleranceLactase-Phlorizin HydrolaseDisaccharidasesSucraseLactoseGalactosidasesLactose Tolerance Testbeta-GalactosidaseJejunumIntestine, SmallMilkDelayed DiagnosisPrenatal DiagnosisEarly DiagnosisSucrase-Isomaltase Complexalpha-GlucosidasesSensitivity and SpecificityMicrovilliIntestinal MucosaDiagnosisIntestinesShallotsRadiometric DatingSprue, TropicalBreath Tests