Why do babies spit up?

[mme_highlight] Spitting up is very common: approximately half of infants between birth and three months have at least one episode of spiting up each day. This can become a disease – Gastroesophageal Reflux Disease (GERD) – when the acid that comes from the stomach causes irritation or injury in the esophagus. This happens in a minority of infants. [mme_highlight]

The term “spit up”, although of common use, can be misleading as it does not differentiate between two terms: reflux or regurgitation, which happens when gastric content returns to mouth, without any muscle pulling it up; vomit, which refers to expelling gastric content pulled by abdominal and thoracic muscles.
It can be hard for parents to tell if their child is vomiting or spitting up, because some babies reflux in large amounts or in an apparently forceful way. However, generally, the term spitting up is used to describe gastroesophageal reflux, which is a medical term.

What is Gastroesophageal reflux?

Reflux can be described as an effortless regurgitation of the gastric content and it happens in healthy babies, children and adults. It can be useful to remember the pathway of food: it goes from the mouth and down the esophagus to reach the stomach, passing through a muscle called lower esophageal sphincter; the function of this sphincter is to loose in order to let food pass to the stomach and then to contract to prevent that food going backwards to the esophagus.
Spitting up is, indeed, very common: approximately half of infants between birth and three months have at least one episode of spiting up each day. This can become a disease – Gastroesophageal Reflux Disease (GERD) – when the acid that comes from the stomach causes irritation or injury in the esophagus. This happens in a minority of infants. There are some signs and symptoms that can be cues to this disease; if this is the case, take your child to see a doctor:

Refusal to eat and frequent crying or leaning the neck and back, as if in pain.
Frequent coughing.
Persistent forceful vomit.
Inadequate weight progression.

If reflux is not pathologic (like in GERD) it is not likely to cause pain and thus it is not probably a cause of irritability or difficulty to sleep in a child, as it is frequently believed.

When will my baby stop spitting up?

As mentioned above, reflux can happen sparsely in any healthy children or adult. However you will notice the frequency of spitting up will decrease as your child grows, as shown below.

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Rate of cessation of reflux (when spitting up stops)

spitting up almost disappears in more than 50% of infants as they reach 10 months;
in 80% of infants by 18 months;
in 98% among 2-year-olds.

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When should I be worried?

Seek for medical advice if your child has acid reflux accompanied by the following symptoms:

Recurrent pneumonia or coughing (this can mean your infant inhalates the regurgitated aliments).
Fail to gain weight.
Recurrent vomiting, diarrhea or blood in the stools.
Long period crying or persistent refusal to drink or eat.

It is important to understand that infections, like gastroenteritis, can be a cause of vomits. Go to a doctor if your child has vomits accompanied by other signs and symptoms like fever. Note also that forceful vomits in infants can be an alarm sign for a serious condition, like in pyloric stenosis, which is a constriction in the stomach, and in intestinal obstruction, when an intestine region gets blocked.

How to treat reflux?

There is no recommendation to treat infants with uncomplicated reflux – as stated above, it will disappear with growth. There are some simple measures that can improve reflux, like thickening the food offered and avoidance of tobacco smoke. In fact, one study revealed that such conservative measures alone can improve reflux in more than 80% of infants.

Summary and Recommendations

Spitting up is very common in infants. Almost 50% of infants present at least one reflux episode per day till 3 months of age.
In most children reflux episodes have stopped by the age of 2.
If the reflux episodes cause injury to the esophagus it is called Gastroesophgeal Reflux Disease (GERD).
Refusal to eat, frequent cough or inadequate weight gain should be alarm signs.
Take your child to a doctor if she/he presents with vomit and other symptoms like fever.

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References

Vandenplas Y, Rudolph CD, Di Lorenzo C, et al. Pediatric gastroesophageal reflux clinical practice guidelines: joint recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN). J Pediatr Gastroenterol Nutr 2009; 49:498.
Nelson SP, Chen EH, Syniar GM, Christoffel KK. One-year follow-up of symptoms of gastroesophageal reflux during infancy. Pediatric Practice Research Group. Pediatrics 1998; 102:E67.
Orenstein SR, Magill HL, Brooks P. Thickening of infant feedings for therapy of gastroesophageal reflux. J Pediatr 1987; 110:181.

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