A gastrointestinal device for implanting within a patient's gastrointestinal tract, the device having a central axis and a first expandable portion comprising a hollow tubular braided structure of wire and having a first cylinder extending parallel to the central axis, the first cylinder having a length and a first face; a neck portion extending from the first face of the first expandable portion parallel to the central axis, the neck portion having a first end, a second end, a wall extending between the first end and second end, and a diameter sized to fit within a pylorus; and a second expandable portion comprising a hollow tubular braided structure of wire and having a second cylinder extending parallel to the central axis, the second cylinder having a second face located at the proximal end of the second cylinder and oriented transverse to the central axis.