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 stomach 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 to the stomach and a flexible sleeve. When implanted within the intestine, the sleeve can limit the absorption of nutrients, delay the mixing of chyme with digestive enzymes, altering hormonal triggers, providing negative feedback, and combinations thereof. The anchor is collapsible for endoscopic delivery and removal.