Gastroenterology deals with disorders of the digestive system including oral, esophageal, gastric, intestinal and accessory gland diseases. Gastroparesis causes symptoms like heartburn, nausea, vomiting and erratic blood sugar levels due to slow stomach emptying which can be caused by stomach surgery, diabetes, eating disorders or nervous system disorders. Treatment involves eating small, low-fiber and low-fat meals frequently and chewing food well.