Bariatric surgery is surgery on the stomach and/or intestines to help a person, with extreme obesity, lose weight. It promotes weight loss by increasing the feeling of fullness and satisfaction after small meals through restriction of the stomach size and/or reducing the absorption of calories by changing the digestive system’s anatomy.
Bariatric surgery is the clinical term for several different procedures. The procedures use one or both of two approaches to help patients lose weight and improve or resolve obesity-related or "co-morbid" conditions.
These different methods work to help patients lose excess weight, lower their BMI, and transform their health by resolving or improving co-morbid conditions. Bariatric surgery has many benefits that can lead to a healthier, higher quality of life. It also has certain risks.
During these procedures, the surgeon creates a small stomach pouch, that limits the amount of food patients can eat. The smaller stomach pouch fills quickly, which helps patients feel satisfied with less food.
During these procedures, the surgeon reroutes the small intestine so that food skips a portion of it. The small intestine absorbs calories and nutrients from food, and avoiding part of it means that many calories and nutrients are not absorbed.
Surgeons rarely perform strictly malabsorptive procedures. Most procedures that use malabsorption also use restriction.
Certain procedures use both restriction and malabsorption. For example, Roux-en-Y gastric bypass surgery uses a combination of restriction and malabsorption. During the procedure, the surgeon creates a small pouch. The surgeon then attaches a Y-shaped section of the small intestine directly to the stomach pouch. This allows food to bypass a large portion of the small intestine, which absorbs calories and nutrients. The smaller stomach pouch causes patients to feel fuller sooner and eat less food; bypassing a portion of the small intestine means the patient’s body absorbs fewer calories.
Examples of combination procedures include gastric bypass.
"Bariatric surgery can result in long-term weight loss and significant reductions in cardiac and other risk factors for some severely obese adults." —American Heart Association
"Bariatric surgery should be considered for adults with BMI >35 and type 2 diabetes, especially if the diabetes is difficult to control with lifestyle and pharmacologic therapy." —American Diabetes Association
"Bariatric surgery is the most effective therapy available for morbid obesity and can result in improvement or complete resolution of obesity and co-morbidities." —American Society for Metabolic and Bariatric Surgery
Video showing various bariatric procedures: