It can happen multiple times a day, particularly after feeds. It happens when food is swallowed into the stomach, but then regurgitates back into the oesophagus (food pipe). Sometimes it then drops back into the stomach (and down the gastrointestinal tract) or sometimes it washes back up to the mouth or further, causing a vomit or spill of feed.
Why do so many babies get reflux?
When we swallow food, multiple factors usually combine to keep it in the stomach.
First, people generally sit up to eat, so gravity assists the food staying down.
Second, we usually eat food with enough weight and density to stay in the stomach.
Third, we have a lower oesophageal sphincter, which is a muscular band around the lower end of the oesophagus, helping stop food coming back up.
Fourth, our oesophagus is quite long, helping to increase the distance food would have to travel to come back up.
In babies, these factors are not there. They lie down most of the time, consume only liquid, their muscles are not yet as well developed as they will become, and their oesophagus is still relatively short. As a result, babies are far more likely to have some degree of regurgitation of their milk.
Reflux isn’t necessarily a bad thing for babies. If they have swallowed a large amount of milk (and air) during a feed, reflux is a way the body can help to reduce the pressure, and relieve the discomfort of an overfull stomach.
What are the symptoms?
Reflux happens very commonly in babies, and many don’t show any symptoms.
The most common symptom of reflux is a small spill of milk after a feed. Sometimes when the milk mixes with stomach acid then washes back up the oesophagus, the resulting regurgitation causes pain.
Other symptoms may include distress or discomfort with feeds, crying during or after feeds or more significant vomiting with feeds. Some babies will refuse or vomit so much of their feed they are unable to gain weight. Some even lose weight.
It’s important to bear in mind many of these symptoms can be caused by issues other than reflux such as colic, cow’s milk protein intolerance, infections and underlying gastrointestinal disorders. A medical review is useful to help look for any other causes prior to making a diagnosis of reflux.
Silent reflux is usually used to describe a baby who is regurgitating a meal into the oesophagus but not as far as the mouth.
It can still lead to discomfort and distress, but doesn’t cause a vomit or a spill of milk. In this way, it can be difficult for a parent to identify the cause of the distress.
This is because the particular features of babies which cause reflux (lying down, consuming only liquid, having relatively underdeveloped muscles and a shorter oesophagus) improve with time. Additionally, some of the treatments themselves can be harmful or may not work.
Lots of different medications have been trialled for reflux. In general, they’re only recommended for babies with poor weight gain or significant distress, as well as regurgitation. They’re not generally recommended as their effects have been found to be poor on simple regurgitation. They also tend to have some side effects including chest infections, abdominal pain and vomiting – the very symptoms they are used to prevent.
Alginate substances made for babies (such as gaviscon infant) work by thickening the feed and forming a coating over the lower oesophagus and stomach. These can help with some symptoms. They contain a relatively high amount of salt, so should only be used after consulting with a doctor. It should also not be used with formula thickeners.
Some formula thickeners may help in bottle-fed babies. Thicker feeds encourage the milk to stay down in the stomach and make it harder to wash back up the oesophagus. But, thicker feeds can be harder for a baby to suck and swallow, and can affect the nutritional content of the formula. Similarly, reducing the volume of feeds might reduce reflux, but may also impact on the nutrition and growth of a baby. The number of feeds in a day may need to be increased if the volume of each feed is reduced.
While there are some surgical options, these are usually reserved for older children with severe reflux or those with complications.
Treatment without medication can be effective. This includes letting a baby lie prone (tummy down) or on their left side while still awake and settling after a meal, provided they are supervised. Never let a baby sleep in these positions, as they are associated with an increased risk of SIDS (sudden infant death syndrome).
With excessive vomiting, babies can have difficulty gaining weight. Frequent regurgitation of stomach acid can occasionally cause trauma to the oesophagus. Some of the milk can wash into the trachea (windpipe), causing breathing difficulty or infection.
Does it ever go away?
Very few babies (less than 5%) with reflux have any ongoing symptoms by the time they are around one year old.
In the meantime, make sure your baby’s weight is being monitored and a health professional has assessed your baby to ensure the most likely diagnosis is reflux. Be aware that while very common, reflux goes away with time, and becomes less frequent with time. Further treatment and tests are not usually helpful.
A one- to two-week trial of feed thickener for bottle-fed babies or infant alginate preparations for breast-fed babies may have some effect, but only if suggested by your doctor. Don’t persist with these if your baby doesn’t improve.
Other medications are only advisable if your baby has particular other signs and should be prescribed at the discretion of a medical professional. Practical measures such as letting a baby lie on their tummy while awake and supervised after a meal may offer some improvement, so long as the baby is never allowed to sleep in this position.
Kirsten Thompson does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.