Unfortunately an intragastric balloon can not be used to undo weight regain after a gastric bypass. The balloon can not be placed (it is an absolute contraindication) whenever there has been previous stomach surgery. That includes gastric bypass. Some degree of weight regain after gastric bypass is a common occurrence, but every attempt should be made to keep it under 25% of the total weight previously lost. In my opinion, weight regain beyond that amount should warrant investigations. The causes are various and complicated, including anatomical, nutritional, psychological or some combination thereof. To best figure out why you are having trouble with weight regain and how it can be reversed, I would get a thorough evaluation by a Bariatric surgeon who has experience with revisional surgery. That way they have options at their disposal, and will be less likely to reflexively blame you as the reason the operation is not working and send you home with a prescription to "try harder." Good luck, and don't forget how far you have come since before your gastric bypass in the first place.