Gastrointestinal surgery for obesity, also called bariatric surgery, alters the digestive process. These operations promote weight loss by closing off parts of the stomach to make it smaller. Operations that only reduce stomach size are known as restrictive operations because they restrict the amount of food the stomach can hold.
Gastrointestinal surgery is a good option for people who are severely obese and cannot lose weight by traditional means or who suffer from serious obesity-related health problems. The surgery promotes weight loss by restricting food intake and, in some operations, interrupting the digestive process. As in other treatments for obesity, the best results are achieved with healthy eating behaviors and regular physical activity. The concept of gastrointestinal surgery to control obesity grew out of results of operations for cancer or severe ulcers that removed large portions of the stomach or small intestine. Because patients undergoing these procedures tended to lose weight after surgery, some physicians began to use such operations to treat severe obesity.