The anti-obesity stent includes a tubular structure having outer and inner surfaces and proximal and distal ends. The tubular structure is sized to fit within a duodenum in substantially coaxial relation therewith. The tubular structure is impervious or semi-permeable to digestive substances and chyme within the duodenum. The anti-obesity stent includes a transport structure at least a part of which is coincident with or connected to the outer surface. The transport structure extends to the distal end of the tubular structure. At least one retainer structure is connected to the tubular structure. The retainer structure secures the tubular structure within the duodenum such that the transport structure is positioned to receive digestive fluids from a papilla of Vater on an inner surface of the duodenum. The transport structure provides a conduit for the digestive fluids therein to flow to the distal end.