Gastric Bypass. An established operation that has been used to treat obesity for more than 40 years, the gastric bypass entails creating a small stomach pouch and bypassing three to five feet of intestine. Obese patients typically lose 50-75 percent of their excess weight. Type 2 diabetes is resolved in 80 percent of patients. Gastric Balloons. Gastric balloons (also called intragastric or stomach balloons) are temporary, removable devices that are placed in the stomach by endoscopy (through the mouth) and can remain for up to six months. Patients with a BMI above 30 are eligible for gastric balloons. Balloons help to achieve weight loss by taking up space in the stomach, thereby restricting food intake. In general, gastric sleeve and other weight-loss surgery could be an option for you if: Efforts to lose weight with diet and exercise have been unsuccessful. Your body mass index (BMI) is 40 or higher (extreme obesity). Your BMI is 35 to 39.9 (obesity) and you have a serious weight-related health problem, such as type 2 diabetes, high blood pressure or severe sleep apnea. In some cases, you may qualify for certain types of weight-loss surgery if your BMI is 30 to 34 and you have serious weight-related health problems.