Method and apparatus for limiting absorption of food products in specific parts of the digestive system is presented. A gastrointestinal implant device is anchored in the pyloric portion of the gastrointestinal system and extends beyond the ligament of Treitz. All food exiting the stomach is funneled through the device. The gastrointestinal device includes an anchor for anchoring the device in the pyloric portion and a flexible sleeve that extents into the duodenum. The anchor is collapsible for endoscopic delivery and removal.