The present invention provides methods of treating 
overweight or obese patients with an 
inflatable weight control device that is implanted in the patient's 
digestive tract. A first method comprises the steps of providing the 
weight control device which includes an 
inflatable body having a first 
bulb, a second 
bulb, an intermediate portion, and an internal passageway extending from the first 
bulb through the intermediate portion and to the second bulb. The 
inflatable body includes a valve 
assembly that is grasped by the 
endoscope during 
insertion of the 
weight control device in the patient's 
pylorus. Next, the 
endoscope is used to position the weight control device within the 
pylorus such that the intermediate portion resides within the pyloric valve and the first bulb resides within the pyloric 
antrum. The weight control device is then inflated with the 
endoscope such that the first bulb engages an inner surface of the pyloric 
antrum to form an outlet obstruction within the pyloric 
antrum. This obstruction causes chyme to accumulate 
proximate the first bulb prior to entering the internal passageway where it is then transported through the body and discharged from the second bulb into the patient's 
duodenum. The accumulation of chyme in pyloric antrum and the 
stomach causes the patient to feel full and stop eating. Thus, the treatment method provides a gastric outlet obstruction that slows the passage of chyme into the 
duodenum and as a result, the patient feels full and stops eating after consuming relatively small portions.