Apparatus (90) is provided for use in a stomach of a subject. The apparatus includes a balloon (92), adapted for placement in the stomach, and all anchor (102), coupled to the balloon. The anchor is adapted to prevent the balloon from passing into a duodenum of the subject. The apparatus further includes an inflation tube (96), coupled to the balloon to permit inflation of the balloon, and is adapted to stretch from the stomach to a mouth of the subject to facilitate inflation of the balloon. Other embodiments are also described.