Bariatric SurgeryObesity, MorbidGastric BypassGastroplastyWeight LossBiliopancreatic DiversionObesityBariatric MedicineJejunoileal BypassPostoperative ComplicationsHyperoxaluriaAvitaminosisPreoperative PeriodLaparoscopyTreatment OutcomeAnastomosis, Roux-en-YBody Mass IndexPostoperative PeriodBariatricsGastrectomyInformed Consent By MinorsPostoperative CareProspective StudiesFollow-Up StudiesGastric FistulaPreoperative CareTooth WearRetrospective StudiesDiabetes Mellitus, Type 2Malabsorption SyndromesAnti-Obesity AgentsPatient SelectionPerioperative PeriodGlucagon-Like Peptide 1Gastrointestinal HormonesPeptide YYTime FactorsReoperationRisk FactorsGastric BalloonComorbiditySecondary CarePerioperative Care