Abstract: The invention relates to a transpyloric device for accepting chyme from the stomach and conducting said chyme on in a bypass-like manner through a patient's duodenum; said device is held in place by balloon segments which sit on a preferably radially collapsible and self-erecting transpyloric conducting element; the filling level of the balloon segments, and thus the axial sealing force acting primarily on the shoulder surfaces of the pylorus or the surrounding area thereof, can be adjusted by the user, and the force applied to the stomach and duodenum structures adjoining the pylorus is reduced to a level that is permanently bearable for the organs even when the filling pressure of the segments rolling against each other is elevated. The invention also relates to an applicator for putting a bypass device of said type in place in the region of the transition from the stomach to the duodenum.