Bariatric SurgeryObesity, MorbidLaparoscopyGastric BypassGastroplastyCholecystectomy, LaparoscopicWeight LossBiliopancreatic DiversionPostoperative ComplicationsTreatment OutcomeObesityBariatric MedicineJejunoileal BypassAnastomosis, Roux-en-YLaparoscopesHyperoxaluriaAvitaminosisPreoperative PeriodGastrectomyBody Mass IndexPostoperative PeriodRetrospective StudiesProspective StudiesFollow-Up StudiesOperative TimePostoperative CareBariatricsLength of StayPneumoperitoneum, Artificial