Do your baby's farts stink?

Baby Farts Stink? Find Out Why And What To Do About It!

Medically reviewed by

Dr. Nicole Nabatkhorian
Dr. Nicole Nabatkhorian

MD / PGY-2 Pediatrics

Disclosure: Some of our articles contain links to recommended products or services in which we may receive a commission if you make a purchase.

Parents love their babies so much that it is easy to overlook it if their baby’s farts stink or smell worse than normal. If they are truly smelly, however, then it is necessary to investigate the reason why in case there are more serious issues involved.

Many baby farts do not smell bad and are the natural by-products of digesting breastmilk, formula, or their first solids. If your baby’s farts stink like sulfur, rotten eggs, cabbage, sour milk, metal, or plastic, however, then there may be a food sensitivity, allergy, or other digestive issues causing the problem.

Read on to learn all about what’s causing your baby’s farts to smell so strange, and discover when you should be concerned about an underlying health issue.

Why Do My Baby’s Farts Smell So Bad?

Many parents are all-too-familiar with the sweet smell of their precious little baby. What’s not so sweet, though, is the smell of a stinky baby diaper, which can sometimes surprise you. Babies can tend to have farts just as smelly as the parents. But just what are farts, anyway?

I admit it’s sometimes adorable to hear a little toot escaping from your little one’s diaper. Those tiny little odorless farts can strangely bring a smile to a new parent’s face. These regular farts are natural and shouldn’t be a cause for concern for you and your infant. However, if your little one is emitting strong smells for their backside, you may want to look into the cause and rule out any serious issues.

Farts are a mixture of swallowed air and gas that is made up of the bacteria in your intestines. So, naturally, many things can contribute to the smell and frequency of your baby’s flatulence. Here are some factors that may cause excessive flatulence in infants:

  • An improper feeding technique that’s causing your baby to swallow too much air
  • Gastrointestinal illness caused by a virus, bacteria, etc
  • A newborn’s immature digestive system that hasn’t fully developed
  • Digestive problems
  • Overfeeding
  • Food sensitivity (like with lactose)
  • Colic or excessive crying can cause babies to suck air into their digestive system

As for the smell of infant farts, it’s all about the conditions of the baby’s digestive system and the diet of a breastfeeding mother. Breastmilk, formula, the introduction of solid foods, digestion issues, and allergies can all affect the smell of an infant’s fart.


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In order to determine why your baby’s farts are extra smelly right now, it’s important to know what is normal when it comes to your child’s gas patterns. This includes how often they pass gas and what it typically smells like. Yes, this requires you to get a bit close to your little one! When you know what is normal for your child, you’ll be better able to judge what’s abnormal and a cause for concern.


Does your baby’s fart smell like sulfur? Sulfur can make a fart smell pretty potent, even in a small amount. Certain fruits and veggies are high in sulfur and can get passed to your baby through breastmilk after you eat them.

These sulfur-rich vegetables include:

  • Broccoli
  • Cauliflower
  • Brussel sprouts
  • Beans
  • Kale
  • Spinach

These sulfur-veggie farts are often nothing to be concerned about; they’ll usually pass as your food completes its digestion. However, sulfur compounds from a meat-heavy diet can result in a stronger fart scent. These foods tend to be richer in fiber and starches. So, avoid or limit these foods if you want to reduce sulfur-smelling farts.

Rotten Eggs

Farts that smell like rotten eggs can be similar in scent to sulfur farts.

Breast milk could be a contributor to a rotten egg-smelling fart in infants. Certain foods, like eggs, of course, can have an impact on the smell of you and your breastfed baby’s gas. Eating fiber-rich foods and foods containing sulfur can also make a fart smell like a rotten egg. Take a look at your diet to see if anything could be an underlying cause of stinky farts.


One of the easiest ways to pinpoint why a baby’s fart smells the way it does it to think about which food the scent reminds you of. Cabbage is another cruciferous vegetable (like broccoli and cauliflower) that can have a strong impact on the smell of your baby’s farts if you’re breastfeeding. So, if your baby’s fart smells like cabbage and you breastfeed, think of the last time you enjoyed this dish.

Also, if your baby has recently started eating solid foods, consider aspects of their diet that could have an effect on the smell of their toots.

Sour Milk

The smell of sour milk on your infant’s farts can indicate trouble with digesting lactose.

It is possible for babies to consume too much lactose if you overfeed them. Breast Milk contains both foremilk (which contains more sugars) and hindmilk (which contains more fat). Too much foremilk can cause an excess of lactose that can cause gassiness in infants.

When you are breastfeeding, experts recommend that you empty your breast before moving your child to the next one. That way, your baby is getting the correct balance of nutrients.

You might also want to consider having a conversation with your doctor about switching to a lactose-free formula to help your baby’s sensitive stomach.

Metal or Plastic

If your baby’s farts smell like metal or iron, it could be a result of the iron in their diet.

However, strange or really foul-smelling gas could be an indicator of food sensitivity or an even more serious underlying medical issue. Some smelly gas means that a baby’s digestive system was unable to fully absorb nutrients into the body.

Every baby is different. Some babies are stinkier than others and may not pose a cause for concern. Even still, many infants will develop stinky farts over time. Pay attention to your baby’s normal so that you’ll be better prepared to determine when it’s time to contact the doctor.

Can Breastfed Babies Have Stinky Farts?

Breastfeeding is a beautiful bond between a mother and her child. It creates a connection like no other—which can often go beyond just physical touch. See, when mothers breastfeed their babies, they pass on the nutrients that their bodies create from the food they eat.

Breastfed babies can sometimes have stinky farts because they are exposed to different nutrients, flavors, and smells vicariously through their mother’s milk. Breastfed babies will have different smelling gas patterns based on what Momma has eaten in the past few hours.

For the most part, when you breastfeed, your baby will get a little taste of what you’ve had. Small bits of the food you eat can be passed to your baby through your breastmilk. So, if you eat something that makes you gassy, it may also be affecting your baby.

Here are some foods you may be eating that are causing your baby’s farts to be especially stinky:

  • Eggs
  • Onions
  • Dairy
  • Broccoli
  • Asparagus
  • Starches (potatoes, bread, cakes)

When your baby’s farts stink because of something you ate, it’s often not a reason to worry. You don’t have to drastically change your diet or remove certain foods from the menu. As long as your baby is gaining weight and having regular wet and dirty diapers, everything should be fine. If gas is causing your baby pain or discomfort, however, that may be a cause for concern. (See our tips later on in this article.)

Do Formula-Fed Baby Farts Stink Worse?

The severity of a baby fart smell is all subjective. To you, your baby’s farts may be tolerable, but to another parent, they may smell as strong as a grown adult. Similar to breastfed babies, formula-fed babies can also develop gas issues from their milk and feeding habits.

While formula-fed babies are not introduced to extra nutrients via a mother’s milk, they can still experience digestive concerns that impact the smell and frequency of gas.

Some babies have a hard time digesting regular formula, which can result in gassiness that may have a strong smell. In fact, they might even be allergic to some ingredients in the formula.  Consult with your child’s pediatrician to see if your baby’s inability to break down lactose is the reason for a smelly fart. Or, if you have started solid foods with your baby, pay attention to which foods result in smellier farts.

Why Would a Newborn’s Farts Smell Bad?

Newborn babies are adorable in their innocence and itty bitty size. And before you become a parent, it can often be a challenge to imagine something so tiny making such a big smell. But, newborns definitely can have a pretty stinky fart.

When babies are first born, their whole bodies are experiencing sudden, drastic changes to get them ready for life outside the womb. So, during those first few weeks of life, your newborn has an immature digestive system. The baby is no longer relying on the mother’s nutrients being transferred directly through the umbilical cord. Now, the baby must somewhat independently feed and digest food on their own.

A newborn baby’s organs are still learning how to function, and they lack some of the probiotics that help with regular digestion. This means it can be more difficult for newborns to fully digest certain proteins, carbs, and fats that are found in a mother’s breast milk or baby formula. In the first month, this results in quick digestion, where food passes through your baby’s system quickly, often without fully breaking down. In turn, gas can get trapped in the intestines and cause newborns to fart a lot more often.

In adults, bacteria gather in the gastrointestinal tract to help digest foods more easily. However, babies are born with a clean gut, and the bacteria will take a while to develop in their systems. Newborn babies instead will have pro-bacteria in their systems, which can cause the production of gas and make your infant fart a lot—and make those farts pretty stinky.

Over time, your baby will grow, and their digestive system will mature with them.

By the way, I’ve also created resources on stinky baby hands, stinky baby feet, and stinky baby diapers if you want to check them out!

Baby Farting and Gassiness: When to Be Concerned

Farting is simply an indication that your baby is gassy. This can happen often when your baby is first born, between the ages of two weeks and four months. During this time, as babies are developing, many can become extra gassy, cranky, and fussy.

On average, many babies fart between 15-20 times daily. That’s almost as often as a fully-grown adult! However, excessive farting might mean that your baby is having a hard time with gas in their stomach. Even more, truly foul-smelling farts could mean that a more serious issue is present.

During this time, it’s best to observe your baby’s behavior to make sure he or she is not uncomfortable because of the gas. Look for cries of discomfort or your baby scrunching up his or her face while passing gas. If this gassiness is causing pain or cramping in your baby, speak with your child’s doctor to discuss ways to help relieve gas in your baby and to determine if there is a more serious underlying health issue.

How to Help Your Baby Relieve Gas

If you notice that your baby is experiencing gas pretty often, there are many things you can do to help him or her pass the necessary gas and find a little bit of comfort. Try these techniques to relieve your baby’s gas the next time they have a little farting spell:

  • Use a proper feeding position: Keep your baby’s head higher than the stomach; you can hold your baby at an angle, but make sure he or she is mostly vertical to allow milk and food to be easily swallowed
  • Always burp your baby after a feeding: This can help your baby release gas when he or she can’t do it on their own; sometimes it can be beneficial to break a feeding in half with a little burping
  • Check the bottle nipple: If your baby’s bottle is flowing too fast, it can cause your baby to swallow air and become gassy; instead, try one with a slower flow
  • Give your baby a massage: A gentle tummy rub while your baby is lying on his or her back can help move around some gas in their system
  • Alter your diet: If smelly farts is a no-go for you, examine the foods your baby (or you) are eating to make sure none are causing gas issues
  • Bicycle kicks: Move the baby’s legs back and forth as in a bicycle motion. This will help the baby release gas. It helps with intestinal motion
  • Tummy time: placing your baby on his or her stomach is also a good way to push out gas

Check out the web story version of this article here!

Joshua Bartlett
Joshua Bartlett

My name is Joshua Bartlett I run this blog with my wife Jarah. We have more than 11 years of parenting experience including three girls and one boy. I started this blog in late 2018 when I realized that I was dealing with baby-related issues on a constant basis…please read more about me here!

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