Gastroparesis (GP also called delayed gastric emptying) is a medical condition consisting of a paresis (partial paralysis) of the stomach, resulting in food remaining in the stomach for an abnormally long time. Normally, the stomach contracts to move food down into the small intestine for additional digestion. The vagus nerve controls these contractions. Gastroparesis may occur when the vagus nerve is damaged and the muscles of the stomach and intestines do not properly function. Food then moves slowly or stops moving through the digestive tract.