A system for treating reflux disease of an obese patient having a stomach with a food cavity, the system comprising: at least one volume filling device for treating obesity and an implantable movement restriction device (10, 310) for treating reflux, the at least one volume filling device and the implantable movement restriction device (10, 310) being either a single, combined device or separate devices, wherein the at least one volume filling device is adapted to be at least substantially invaginated by a stomach wall portion of the patient and having an outer surface that includes a biocompatible material, wherein the at least one volume filling device is adapted to be placed with the outer surface of the at least one volume filling device resting against the stomach wall, such that the volume of the food cavity is reduced in size by a volume substantially exceeding the volume of the at least one volume filling device, the at least one volume filling device having a maximum circumference of at least 30 millimeters when implanted, and wherein the implantable movement restriction device (10, 310) is adapted to be at least partly invaginated by the patient's stomach fundus wall without encircling the oesophagus and having an outer surface that includes a biocompatible material, wherein a substantial part of the outer surface of the movement restriction device (10, 310) is adapted to rest against the stomach wall without injuring the latter in a position between the patient's diaphragm and at least a portion of the lower part of the invaginated stomach fundus wall, such that movement of the cardiac notch of the patient's stomach towards the patient's diaphragm is restricted, when the movement restriction device (10, 310) is invaginated, to thereby prevent the cardia from sliding through the patient's diaphragm opening into the patient's thorax, so as to maintain the supporting pressure against the patient's cardia sphincter muscle exerted from the patient's abdomen, characterised in that the system further comprises: an implantable stimulation device adapted to engage with the cardia sphincter of the patient, an energy source (30, 34a) for supplying energy to the implantable stimulation device, and a control device for controlling the energy source (30, 34a) to deliver electrical pulses to the implantable stimulation device to stimulate the cardia sphincter for increasing a sphincter tonus so that the cardia closes. at least one volume filling device for treating obesity and an implantable movement restriction device (10, 310) for treating reflux, the at least one volume filling device and the implantable movement restriction device (10, 310) being either a single, combined device or separate devices, wherein the at least one volume filling device is adapted to be at least substantially invaginated by a stomach wall portion of the patient and having an outer surface that includes a biocompatible material, wherein the at least one volume filling device is adapted to be placed with the outer surface of the at least one volume filling device resting against the stomach wall, such that the volume of the food cavity is reduced in size by a volume substantially exceeding the volume of the at least one volume filling device, the at least one volume filling device having a maximum circumference of at least 30 millimeters when implanted, and wherein the implantable movement restriction device (10, 310) is adapted to be at least partly invaginated by the patient's stomach fundus wall without encircling the oesophagus and having an outer surface that includes a biocompatible material, wherein a substantial part of the outer surface of the movement restriction device (10, 310) is adapted to rest against the stomach wall without injuring the latter in a position between the patient's diaphragm and at least a portion of the lower part of the invaginated stomach fundus wall, such that movement of the cardiac notch of the patient's stomach towards the patient's diaphragm is restricted, when the movement restriction device (10, 310) is invaginated, to thereby prevent the cardia from sliding through the patient's diaphragm opening into the patient's thorax, so as to maintain the supporting pressure against the patient's cardia sphincter muscle exerted from the patient's abdomen, characterised in that the system further comprises: an implantable stimulation device adapted to engage with the cardia sphincter of the patient, an energy source (30, 34a) for supplying energy to the implantable stimulation device, and a control device for controlling the energy source (30, 34a) to deliver electrical pulses to the implantable stimulation device to stimulate the cardia sphincter for increasing a sphincter tonus so that the cardia closes. an implantable stimulation device adapted to engage with the cardia sphincter of the patient, an energy source (30, 34a) for supplying energy to the implantable stimulation device, and a control device for controlling the energy source (30, 34a) to deliver electrical pulses to the implantable stimulation device to stimulate the cardia sphincter for increasing a sphincter tonus so that the cardia closes.