The present invention provides an endoscopically implantable weight control device that forms a gastric outlet obstruction in a patient's digestive tract. The weight control device includes an inflatable body residing within the patient's pylorus and between the stomach and duodenum. The body features a first bulbous portion and a second bulbous portion, the exterior dimensions of the first bulbous portion exceeding the exterior dimension of the second bulbous portion. The body also includes an intermediate portion with exterior dimensions that are less than the exterior dimensions of both the first and second bulbous portions, wherein the intermediate portion resides within the patient's pyloric valve when the device is implanted. An internal passageway extends through the body, wherein the passageway receives and allows for the passage of chyme from the stomach to the duodenum. A method of treating obese patients with the inflatable weight control device utilizing a sequence of different-sized devices is also provided.
