How infant reflux occurs
If the muscle between the esophagus and the stomach (lower esophageal sphincter) relaxes at the wrong time, stomach contents might flow up the baby's esophagus.
Infant reflux occurs when food backs up (refluxes) from a baby's stomach, causing the baby to spit up. Sometimes called gastroesophageal reflux (GER), the condition is rarely serious and becomes less common as a baby gets older. It's unusual for infant reflux to continue after age 18 months.
Reflux occurs in healthy infants multiple times a day. As long as your baby is healthy, content and growing well, reflux is not a cause for concern.
Rarely, infant reflux can be a sign of a medical problem, such as an allergy, a blockage in the digestive system or gastroesophageal reflux disease (GERD).
Infant reflux generally isn't a cause for concern. It's very unusual for the stomach contents to have enough acid to irritate the throat or esophagus and to cause signs and symptoms.
When to see a doctor
See your baby's doctor if your baby:
- Isn't gaining weight
- Consistently spits up forcefully, causing stomach contents to shoot out of his or her mouth (projectile vomiting)
- Spits up green or yellow fluid
- Spits up blood or a material that looks like coffee grounds
- Refuses food
- Has blood in his or her stool
- Has difficulty breathing or a chronic cough
- Begins spitting up at age 6 months or older
- Is unusually irritable after eating
Some of these signs can indicate possibly serious but treatable conditions, such as GERD or a blockage in the digestive tract.
In infants, the ring of muscle between the esophagus and the stomach — the lower esophageal sphincter (LES) — is not yet fully mature. That allows stomach contents to flow backward. Eventually, the LES will open only when your baby swallows and will remain tightly closed at other times, keeping stomach contents where they belong.
The factors that contribute to infant reflux are common in babies and often can't be avoided. These factors include:
- Babies lying flat most of the time
- An almost completely liquid diet
- Babies being born prematurely
Occasionally, infant reflux can be caused by more-serious conditions, such as:
- GERD. The reflux has enough acid to irritate and damage the lining of the esophagus.
- Pyloric stenosis. A valve between the stomach and the small intestine is narrowed, preventing stomach contents from emptying into the small intestine.
- Food intolerance. A protein in cow's milk is the most common trigger.
- Eosinophilic esophagitis. A certain type of white blood cell (eosinophil) builds up and injures the lining of the esophagus.
Infant reflux usually clears up by itself without causing problems for your baby.
If your baby has a more-serious condition such as GERD, he or she might show signs of poor growth. Some research indicates that babies who have frequent episodes of spitting up may be more likely to develop GERD during later childhood.