Infant reflux is related to a number of factors, often in combination with one another.

In infants, the ring of muscle between the esophagus and the stomach — the lower esophageal sphincter (LES) — is not yet fully mature, allowing stomach contents to flow backward. Eventually, the LES will open only when baby swallows and will remain tightly closed the rest of the time, keeping stomach contents where they belong.

Babies are lying flat most of the time, which makes reflux more likely. Moreover, their diet is completely liquid, also favoring infant reflux. Sometimes air bubbles in the stomach may push liquids backward. In other cases, your baby may simply drink too much, too fast.

Although infant reflux most often occurs after a feeding, it can happen anytime your baby coughs, cries or strains.

In a small number of cases, the symptoms of infant reflux are caused by something else. Among the possibilities:

  • Allergic gastroenteritis is an intolerance to something in food, usually a protein in cow's milk.
  • Gastroesophael reflux disease (GERD) is a more severe condition where the reflux is acidic enough to actually irritate and damage the lining of the esophagus.
  • Eosinophilic esophagitis is a condition where a particular type of white blood cell (eosinophil) builds up and injures the lining of the esophagus.
  • Obstruction is a blockage or narrowing in the esophagus (esophageal stricture) or between the stomach and small intestine (pyloric stenosis).
Mar. 28, 2013

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