Incidence of De Novo Gallstone Formation Following Metabolic Bariatric Surgery: A Systematic Review and Meta-analysis

Obesity is strongly associated with gallstone formation, primarily due to alterations in cholesterol metabolism and biliary physiology. Individuals with severe obesity frequently undergo metabolic bariatric surgery (MBS) as an effective intervention for sustained weight reduction and improvement of obesity-related comorbidities. However, rapid postoperative weight loss and metabolic changes following bariatric procedures may increase the risk of gallstone formation. Although gallstones represent a recognised postoperative complication of MBS, reported incidence rates vary widely across the literature. Differences in study design, follow-up duration, surgical procedure, and surveillance strategies contribute to substantial variability in reported outcomes. Consequently, the true incidence of de novo gallstone formation following MBS remains uncertain. A systematic synthesis of recent literature is therefore required to determine the pooled incidence of postoperative gallstones following bariatric surgery and to provide updated evidence to inform clinical surveillance and preventive strategies. Existing evidence suggests that gallstones occur in a notable proportion of patients after MBS, highlighting the importance of clarifying the magnitude of this complication.