Pancreatic Exocrine Insufficiency After Metabolic and Bariatric Surgery

Obesity is a chronic disease characterized by an abnormal or excessive accumulation of body fat. Common interventions include lifestyle changes, hypocaloric diets, and incretin mimetics, all of which have limited efficacy. Metabolic and bariatric surgery (MBS) continues to gain prominence as an effective treatment for obesity, owing to sustained weight loss and improvement in comorbid conditions. Pancreatic exocrine insufficiency (PEI) is an under-recognized but clinically significant complication of MBS. It is characterized by inadequate pancreatic enzyme secretion, resulting in fat malabsorption and micronutrient deficiencies. The true prevalence of PEI in the post-MBS population remains poorly defined due to inconsistencies in diagnostic criteria and underrecognition in clinical practice. The pathophysiology of PEI in this setting is multifactorial and includes loss of pancreaticocibal synchrony, diminished hormonal stimulation of the pancreas, and alterations in the gut microbiome such as small intestinal bacterial overgrowth. Clinical manifestations are often subtle or nonspecific, contributing to diagnostic delays. Although imperfect, the fecal elastase-1 (FE-1) test remains the most commonly used diagnostic tool in clinical practice. Current guidelines suggest that pancreatic enzyme replacement therapy (PERT) may be considered in post-bariatric patients with confirmed or suspected PEI, although data on efficacy and optimal dosing in this population are limited. This review synthesizes current evidence on epidemiology, etiopathogenesis, clinical presentation, diagnostic challenges, and management of PEI following MBS. We also summarize insights from recent studies and discuss the clinical implications of timely recognition and treatment of this underappreciated complication.