An artificial stomach for replacing the normal stomach of a patient who has had his/her stomach surgically removed, comprising: a food reservoir adapted to collect food, an inlet connected to a first opening of the food reservoir and further being adapted to upstream connect to the patient's gastrointestinal tract, and an outlet connected to a second opening of the food reservoir and further being adapted to downstream connect to the patient's gastrointestinal tract, and a connector adapted to upstream connect the inlet to the patient's gastrointestinal tract, or downstream connect the outlet to the patient's gastrointestinal tract, said connector comprising a conduit fixedly attached at a first, proximal end on the outside the artificial stomach and in fluid connection to the food passageway, where the proximal part of the conduit is formed like a tube, and distal to the tube a bulge is formed, wherein the connector further comprises at least one of: a blocking ring arranged to be pushed against the bulge, the ring having an inner diameter less than the outer diameter of said bulge but large enough to allow the intestinal/oesophageal wall to be placed between said ring and said tube, thereby adapted to stop said intestinal/oesophageal wall from slipping away from the tube; and a flexible sleeve arranged to be rolled upon itself and then unrolled to cover part of the tube and the oesophagus or intestine, which is arranged to be pulled over the second end of the conduit sufficiently far so as to extend also over the bulge. a food reservoir adapted to collect food, an inlet connected to a first opening of the food reservoir and further being adapted to upstream connect to the patient's gastrointestinal tract, and an outlet connected to a second opening of the food reservoir and further being adapted to downstream connect to the patient's gastrointestinal tract, and a connector adapted to upstream connect the inlet to the patient's gastrointestinal tract, or downstream connect the outlet to the patient's gastrointestinal tract, said connector comprising a conduit fixedly attached at a first, proximal end on the outside the artificial stomach and in fluid connection to the food passageway, where the proximal part of the conduit is formed like a tube, and distal to the tube a bulge is formed, wherein the connector further comprises at least one of: a blocking ring arranged to be pushed against the bulge, the ring having an inner diameter less than the outer diameter of said bulge but large enough to allow the intestinal/oesophageal wall to be placed between said ring and said tube, thereby adapted to stop said intestinal/oesophageal wall from slipping away from the tube; and a flexible sleeve arranged to be rolled upon itself and then unrolled to cover part of the tube and the oesophagus or intestine, which is arranged to be pulled over the second end of the conduit sufficiently far so as to extend also over the bulge. a blocking ring arranged to be pushed against the bulge, the ring having an inner diameter less than the outer diameter of said bulge but large enough to allow the intestinal/oesophageal wall to be placed between said ring and said tube, thereby adapted to stop said intestinal/oesophageal wall from slipping away from the tube; and a flexible sleeve arranged to be rolled upon itself and then unrolled to cover part of the tube and the oesophagus or intestine, which is arranged to be pulled over the second end of the conduit sufficiently far so as to extend also over the bulge.