This is usually differentiated from vomiting. Vomiting occurs with abnormal forceful contractions of the stomach whereas GER occurs with the normal churning contractions of the stomach. Some amount of GER is normal and is considered physiologic or benign. Such episodes are brief, asymptomatic and self-limited. This is due to the lower tone of the lower esophageal sphincter in infants.
Most infants stop spitting up before their first birthday.
Children with neurological disorders are at much higher risk of having significant GER that persists past infancy and that is pathologic. There are two major physiologic barriers that normally prevent significant reflux of stomach contents into the esophagus. The LES should contract when the stomach contracts, preventing stomach contents from refluxing into the esophagus. If the tone of the LES is low, GER is more likely to occur. The second barrier to significant GER is the motility of the lower part of the esophagus.