The present invention describes a medical implant for treating pathological obesity, which is adapted to modify and, as an alternative, to bypass the natural food passage in the digestive tract. In contrast to purely surgical methods of food bypassing, the properties of the present implant permit an adjustable bypassing of food into the small intestine and/or into the stomach (natural digestive path). Since the ratio of this bypass is adjustable in the course of the treatment by the physician, e.g. with the aid of an endoscope, for the first time a balance between the therapeutic effect and the side-effects can be adapted individually to each patient by the use of the implant. The present invention is a hollow body 1 comprising a first and a second tubular end portion 2, 3 and at least one third lateral opening having a hose-like extension 8. It is provided that individual, at least partly closable hose-like extensions 8 differ in their ability to allow the passage of food into the stomach 11. The possibility to close individual hose-like extensions 8 at least partially by means of an endoscope leads to an individually adjustable distribution of food between the stomach 11 and the small-intestine loop 12.