Anemia, PerniciousHelicobacter pyloriGastritisHelicobacter InfectionsIntrinsic FactorGastritis, AtrophicAchlorhydriaHelicobacterGastric MucosaAnemiaSchilling TestVitamin B 12Anemia, MacrocyticVitamin B 12 DeficiencyGastrinsStomachCobalt IsotopesParietal Cells, GastricAnemia, MegaloblasticPostgastrectomy SyndromesGastric JuiceHydroxocobalaminStomach NeoplasmsGastroscopyUreaseAnemia, HypochromicPyloric AntrumPeptic UlcerDyspepsiaDuodenal UlcerHelicobacter heilmanniiAmoxicillinClarithromycinStomach DiseasesMetronidazoleHelicobacter hepaticusAnti-Ulcer AgentsMetaplasiaAutoimmune DiseasesCarcinoid TumorGastric AcidEnterochromaffin CellsStomach UlcerAnemia, AplasticOmeprazoleGastric FundusZollinger-Ellison SyndromeBacterial ProteinsAutoantibodiesPepsinogen AAnemia, HemolyticH(+)-K(+)-Exchanging ATPasePolypsMalabsorption SyndromesFolic Acid DeficiencyCobalt RadioisotopesEndocrine System DiseasesEthylaminesVitiligoGastritis, HypertrophicBismuthFanconi AnemiaAgammaglobulinemiaAntibodies, BacterialEdrophoniumPrecancerous ConditionsBreath TestsBiopsyDuodenitisFolic Acid