Adaptations in gastrointestinal physiology after sleeve gastrectomy and Roux-en-Y gastric bypass

Summary Linked to the growing obesity epidemic, demand for bariatric and metabolic surgery has increased, most common procedures being sleeve gastrectomy Roux-en-Y gastric bypass. Originally, were described as purely restrictive, malabsorptive, or combined restrictive–malabsorptive limiting food intake, nutrient absorption, both. Nowadays, anatomical alterations are known affect gastrointestinal physiology, which in turn affects digestion absorption of nutrients drugs. Therefore, understanding physiology is crucial prevent postoperative nutritional deficiencies optimise drug therapy. Preclinical clinical research indicates that accelerates liquid solid emptying small intestinal transit, increases bile acid serum levels, whereas its effects on acidity, pancreatic secretions, surface area, colonic transit remain largely unknown. bypass diminishes secretion, emptying, but pH, time, enzyme area In this Review, we summarise current knowledge these two assess gaps.