Stomach acid is usually neutralized and washed out of the esophagus by saliva. Individuals who have reflux do not produce saliva, which prolongs the period in which the esophagus is bathed in acid and increases the chances of developing a severe esophageal injury. Although most patients with GERD produce normal amounts of acid, those with excessive acid production are more likely to have an esophageal injury when reflux occurs. Occasionally, individuals with reflux have a disorder of gastric emptying, resulting in an increased chance of reflux. In most cases, the aforementioned complications increase the severity of reflux in patients who are already predisposed to this condition due to a weak anti-reflux barrier. Only rarely do they create pathologic reflux in an individual not otherwise predisposed to developing reflux.