Your infant is gassy because their digestive system is brand new and still learning how to process air and food. Every baby deals with gas, and most of the time it’s completely normal. Newborns spent nine months floating in fluid with no experience handling air, so when they start breathing, feeding, and crying, swallowed air has to go somewhere. Combine that with an immature gut that’s still figuring out digestion, and you get a baby who grunts, squirms, turns red, and wakes from sleep struggling to pass gas.
Why Newborn Digestion Produces So Much Gas
Two things create gas in your baby’s gut: swallowed air and bacterial fermentation. Air gets in every time your baby feeds, cries, or even breathes with their mouth open. Some of that air comes back up as a burp, but the rest travels through the intestines and needs to come out the other end.
The second source is the bacteria that naturally colonize your baby’s gut in the first weeks of life. As breast milk or formula moves through the intestines, some of it isn’t fully digested. Gut bacteria feed on what’s left over and produce gas as a byproduct. This is the same process that happens in adult digestion, but babies are dealing with it for the first time, with muscles that aren’t yet coordinated enough to push gas out efficiently. That’s why your newborn balls up, strains, and sometimes screams before finally releasing what turns out to be a surprisingly loud burp or fart.
Feeding Problems That Make It Worse
How your baby feeds is one of the biggest factors in how much air they swallow. For breastfed babies, a shallow or poor latch lets air sneak in around the breast with every suck. Babies with tongue tie or lip tie are especially prone to this because they can’t form a tight seal, leading to disorganized swallowing and excess air intake.
For bottle-fed babies, nipple flow matters. A nipple that’s too fast forces your baby to gulp, swallowing air along with milk. A nipple that’s too slow makes them suck harder and pull in air around the sides. Tilting the bottle so milk completely fills the nipple (no air pocket at the tip) can reduce how much air your baby takes in. Frequent burping, every two to three ounces or when switching breasts, gives trapped air a chance to escape before it travels deeper into the digestive tract.
Breast milk is generally easier to digest than formula because of its protein composition, and breastfed babies tend to swallow less air during feeding. That said, breastfed babies still get gassy, sometimes for reasons that have nothing to do with how they latch.
Does Your Diet Affect Your Baby’s Gas?
If you’re breastfeeding, you’ve probably been told to avoid broccoli, beans, garlic, or spicy food. The evidence behind this advice is weak. There are no specific foods that have been proven to cause gas in breastfed infants, and spicy foods have not been shown to cause discomfort either. Most babies tolerate whatever their mothers eat without any issues.
The one real exception is cow’s milk protein. It’s the most commonly reported food substance linked to gas and fussiness in newborns. Some babies react to cow’s milk protein (and sometimes soy) that passes through breast milk, causing irritability, gas, and sometimes changes in stool. If you notice a consistent pattern of your baby being more uncomfortable after you consume dairy, it’s worth discussing an elimination trial with your pediatrician. But cutting out entire food groups “just in case” isn’t necessary for most breastfeeding parents.
Lactose Overload in Breastfed Babies
There’s a common breastfeeding issue that mimics food intolerance but is actually a feeding management problem. Functional lactose overload happens when a baby consistently gets breast milk that’s lower in fat. Breast milk changes composition during a feeding: the milk at the beginning is thinner and higher in lactose, while the milk toward the end is richer in fat. If your baby frequently snacks at the breast without finishing a full feed, or if you switch sides too quickly, they may take in a lot of lactose-heavy milk without enough fat to slow digestion.
The result is that milk rushes through the gut too fast for the baby’s enzymes to break down all the lactose. The undigested lactose ferments in the colon, producing gas, frothy green stools, and a fussy baby who seems hungry again quickly because they didn’t get enough fat to feel satisfied. This isn’t a defect in your milk or your baby. It’s usually resolved by letting your baby finish one breast more completely before offering the other, so they get the higher-fat milk that comes later in the feed.
This is different from true lactose intolerance, which is extremely rare in infants. Babies can develop a temporary, secondary lactose intolerance after a stomach bug or as a result of cow’s milk allergy damaging the intestinal lining, but this resolves once the underlying issue clears up.
Physical Techniques That Help
Since the core problem is that your baby’s muscles aren’t coordinated enough to move gas out, you can help by doing the work for them. Laying your baby on their back and gently cycling their legs in a bicycling motion compresses the abdomen and helps trapped gas move along. This is essentially a gas massage, and many parents find it works within minutes.
Supervised tummy time also helps. The pressure of your baby’s abdomen against a flat surface pushes gas toward the exit. Even a few minutes of tummy time between feeds can make a difference, with the added benefit of strengthening their neck and upper body.
Holding your baby upright for 10 to 15 minutes after a feed gives air bubbles time to rise and come out as burps rather than traveling into the intestines. Some parents find that holding the baby face-down along their forearm (the “colic hold”) provides gentle abdominal pressure that soothes a gassy baby.
Do Gas Drops or Probiotics Work?
Simethicone drops are one of the most popular over-the-counter remedies for infant gas, but the clinical evidence is disappointing. A systematic review published in BMJ Open found moderate to low evidence showing no benefit from simethicone. Across multiple studies and reviews, the data consistently failed to support its use for reducing gas or colic symptoms, with some reviews finding no difference or even worsening of symptoms.
Probiotics tell a more interesting story. A specific strain called Lactobacillus reuteri has been studied in colicky infants with encouraging results. In one randomized, double-blind trial, babies given a probiotic supplement cried an average of 35 minutes per day by the end of three weeks, compared to 90 minutes per day in the placebo group. By day 21, only 4 out of 25 babies in the probiotic group were still crying more than three hours a day, compared to 12 out of 21 in the placebo group. The effect showed up as early as one week in. These results are specific to breastfed, colicky infants, so they may not apply to every gassy baby, but they suggest probiotics are worth discussing with your pediatrician if gas and fussiness are significant.
When Gas Signals Something Else
Gas alone, even lots of it, is rarely a sign of a medical problem. But gas paired with other symptoms can indicate something that needs attention. Watch for poor feeding or refusing the breast or bottle, vomiting or diarrhea, a cry that sounds different from their usual fussing, increased irritability when being held or touched, changes in breathing, or unusual sleepiness. These symptoms in combination suggest something beyond normal newborn gas and warrant a call to your pediatrician.
The reassuring reality is that infant gassiness is one of the most universal and temporary challenges of the newborn period. As your baby’s digestive system matures and their abdominal muscles strengthen over the first three to four months, they get dramatically better at moving gas through on their own. The grunting, straining, and middle-of-the-night fart struggles don’t last forever, even though it can feel that way at 3 a.m.