Gastrointestinal NeoplasmsUpper Gastrointestinal TractStomach NeoplasmsGastrointestinal TractEsophageal NeoplasmsBiopsyPancreatic NeoplasmsDigestive SystemAdenocarcinomaGastrointestinal DiseasesEndoscopy, GastrointestinalGastrointestinal HemorrhageColorectal NeoplasmsFluorouracilDuodenitisEsophageal DiseasesCausticsStomachEndoscopyGastroscopyLiver NeoplasmsDuodenumColonic NeoplasmsBurns, ChemicalDuodenoscopyStomach DiseasesEndoscopes, GastrointestinalPeptic UlcerEsophagoscopyEsophagusTreatment OutcomeGastric MucosaDuodenal NeoplasmsEndoscopy, Digestive SystemGastrointestinal MotilityEsophagitisIleostomyDigestive System Surgical ProceduresBiopsy, NeedleStomach UlcerDyspepsiaGastritisIntestinal MucosaDigestive System Physiological PhenomenaGastric JuiceIntestine, SmallIleumNeoplasms, Multiple PrimaryMucous MembraneBarrett EsophagusAdministration, OralHelicobacter InfectionsGastroesophageal RefluxHelicobacter pyloriAnti-Inflammatory Agents, Non-SteroidalRetrospective StudiesLower Gastrointestinal TractProspective StudiesTime FactorsPostoperative ComplicationsUpper ExtremityIntestinesUrinary Tract InfectionsRisk FactorsHematologic NeoplasmsColon