An apparatus is provided for controlling the food flow through the stomach of an obese patient surgically modified by VBG (Vertical Banded Gastroplasty). In VBG, the stomach is compartmentalized into a smaller proximal compartment adjacent the esophagus and a larger distal compartment, wherein the smaller proximal compartment communicates with the larger distal compartment through an outlet opening. The apparatus comprises an implantable constriction device for gently constricting at least one wall portion of the tissue wall of the patient's stomach (i.e. without substantially hampering the blood circulation in the tissue wall) to influence the food flow in a food passageway extending in the smaller proximal compartment through the outlet opening, and an implantable stimulation device for stimulating the wall portion of the tissue wall. A control device controls the stimulation device to stimulate the wall portion, as the constriction device constricts the wall portion, to cause contraction of the wall portion constricted by the constriction device to further influence the food flow in the food passageway.
