Gastric pacemaker in gastroparesis. Coloured X-ray of a section through the abdomen of a 58-year-old diabetic patient with gastroparesis, showing an implantable gastric stimulator (IGS, round, lower right). Gastroparesis, or delayed stomach emptying, is partial paresis (paralysis) of the stomach that results in food staying in the stomach for an abnormally long length of time before being passed into the intestines. Normally, the stomach contracts at regular intervals to move food into the small intestine. Gastroparesis can occur when the vagus nerve, which controls this contraction, is damaged. IGS uses a pacemaker-like device to send signals to electrodes implanted in the surface of the stomach, which artificially stimulate the contraction of the stomach.