Devices for treatments of diseases and disorders associated with the gastrointestinal tract, especially the stomach, or urinogenital tract are described herein. Initially, the device is in a temporary form which is suitable for oral or rectal administration. After exposure to a stimulus, such as a temperature or pH change, the device changes shape to a permanent form, which allows it to become mechanically fixed in the stomach, esophagus or intestine. In one embodiment, the device is used to reduce the volume of the stomach, esophagus or intestine without interfering with the flow of the food through the gastrointestinal tract. The device may be used to help overweight patients lose weight and to deliver drugs to treat disorders and diseases in the in the stomach or intestine. The devices are manufactured from a stimuli-sensitive polymeric material, which is biocompatible and primarily adapted to the mechanical properties and geometry in the area to which it is applied. In the preferred embodiment, the material is a shape memory polymer. Depending on the desired application, the polymer may be either biodegradable or non-degradable.