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Newborn Baby Spitting Up Yellow? — Bile, Mucus, Breast Milk

Baby Spitting Up Yellow

It’s common for healthy babies to spit up but…why is it yellow? Is this normal?

Here’s what’s behind your baby spitting up yellow, what solutions work, and when it might be a sign of a more serious problem.

Table of Contents
Table of Contents

Why Is My Newborn Spitting Up Yellow? — Causes and What You Need to Do

Your Baby Hasn’t Been Burping

Mother carrying baby

Parents need to take the time to burp your baby.

More frequent burps during and after feeding time can prevent the build-up of air in your baby’s stomach that can lead to yellow spit-up.

Breast milk or formula milk that lingers in the stomach too much leads to fermentation, causing the yellow color and odor of spoiled milk.

This isn’t a serious concern but can cause discomfort to your little one.

So if your child has not had a burp in a while or is experiencing a little bit of constipation, help jump-start their digestive system with a burp session.

Just REMEMBER that yellow spit up here is normal.

Your Baby Has Infant Acid Reflux or Gastroesophageal Reflux Disease (GERD)

Parents taking care of crying baby

Around 50% of newborns around the world experience infant acid reflux or GERD during their first 3 months. This is because their stomach contents come back up the esophagus.

But why does it happen?

Well, it takes time for babies’ stomachs to mature and work properly.

So, until they develop a muscle known as the lower esophageal sphincter to keep food down, yellow spit up can be expected when children are full.

Infant acid reflux or GERD symptoms can be treated easily and prevented by ensuring that children sit upright after eating. This aids food in going down MORE easily and prevents its backflow.

There’s also a chance that you’re feeding your baby too frequently or too much.

Overfeeding can lead to the stuffing of their little tummies, so allow the stomach contents of your little one to settle down first to avoid infant reflux.

You Breastfed Your Baby With Colostrum

Baby sucking on mother's breast

Colostrum, one of the first forms of breastmilk of a mother, is thicker and more yellow in color than usual because it’s filled with antibodies as well as beneficial vitamins and nutrients.

Although yellow mother colostrum promotes growth and health in infants, newborn children CANNOT process this composition as quickly.

So, you might see your baby spitting up yellow in small amounts.

In this case, everything is completely natural, and there is no need to worry at all! Just wait for your regular breastmilk to transition in.

Your Baby Could Be Sick

Mother feeling baby's forehead

Your little one might be fighting a sinus infection, resulting in a build-up of mucus in their throats.

This mucus can reach their stomachs when they lay down and end up in your baby’s spit-up.

In worse cases, the mucus upsets your baby’s tummy and causes him or her to vomit. This is a clear sign to seek medical attention!

If this yellow mucus consistency persists, schedule an appointment with your pediatrician because this is usually a sign of either a sinus infection or some other form of illness in children.

What Babies Spit Up and Why These Happen

Baby with spit in mouth

Spitting Up (Curdled) Breastmilk

Breastmilk changes, as all moms vary as do the days during the breastfeeding period. It’s NEVER the same!

Certain food can affect its flavor or texture and how well your infant digests it.

Milk from breastfeeding from the mother or formula curdles and turns yellow when mixed with the acidic stomach fluid.

It’s possible that a newborn has slight lactose intolerance or allergy to milk protein, causing them to spit it up. Talk to your pediatrician if you suspect an allergy or intolerance.

There could also be something in your diet transferring over to your breastmilk that causes rumbling in the tummy of your little one.

If you’re breastfeeding, AVOID the following foods:

  • Citrus
  • Spicy food
  • Carbonated drinks
  • Food high in fat

These can affect the milk you give your children and lead to acid reflux.

Spitting Up Mucus

Babies spit up a clear liquid or regurgitate food that is milky white, which could be due to their immature digestive system.

This subsides once your baby’s digestive system learns to handle the food.

Mucus in baby spit up is NOT typically a call for concern. While the amount of your baby’s mucus can look like a lot, it’s often a combination of mucus and saliva.

It is normal for children to spit up mucus or what they ate occasionally, but if it occurs more than a few times a day, contains traces of blood, or your kid experiences signs of distress, seek medical attention.

Spitting Up Bright Yellow Bile

Children with GERD can throw up a majority of their tummy contents, which consists of digestive acids and bile a bright yellow/green fluid produced in the gallbladder to aid digestion.

Bright yellow bile often exits with stomach acid when there is a bowel obstruction.

A bright yellow (or even green) color of bile in spit-up can also indicate that there is nothing else back in your baby’s tummy.

The spit-up, and even throw-up, of (bright yellow) bile can quickly lead to dehydration.

If you observe changes/signs of dehydration in your little one, such as crying without tears, it may be the best idea to head to the emergency room.

That way, children can rehydrate with proper fluids.

Without a doubt, visit your pediatrician or family doctor to confirm whether this condition of bright yellow bile spit up is due to virus infection, bowel obstruction, or a serious illness.

Spitting Up Clear Liquid

When children burst bubbles of saliva (the clear liquid you see) from their mouth, it could be a sign of burping issues.

Having clear liquid means it’s more than just gas escaping when they burp.  This often happens if your little one is fed a lot and they either sit or lay down more often.

The spit can also mean your little one is teething. When children are growing a tooth, they start to build up and release a lot more saliva.

Spitting Up Blood

We understand this situation can be one of the scariest things in the world, and, yes, you may want to head to the emergency room immediately.

Signs/symptoms of serious concern include fever, a swollen belly, or lethargy.

If not, DON’T PANIC. It may actually have more to do with the mother than the children.

Potential causes of seeing blood in your baby’s spit-up most likely include:

  • Cracked nipples during breastfeeding
  • Swallowed blood during their delivery
  • Forceful spit-up

However, in rare cases, possible reasons can be:

  • Clotting disorder
  • Milk protein allergy
  • Nose, throat, or esophagus irritation

The Difference Between Spit Up And Vomit

Baby with spit-up

Spit Ups

A baby’s spit-up is the easy passage of the stomach’s content through the children’s mouth and can be observed as dribbling drool. This most often occurs when you burp your infant.

Your little one will most likely NOT notice when they’re doing it.


The difference between spit-ups and vomit may not be obvious from the appearance but rather in the manner of being expelled.

Vomiting is a much more forceful passage or flow of food and is notably projectile. 

As the muscles around the stomach are triggered by the brain to expel immediately, this is what leads to projectile vomiting.

If you sense that your little one is uncomfortable when it happens, he/she is most likely puking.

Frequently Asked Questions About Baby Spit Ups and Vomiting

Baby sleeping on mother's chest

Should I Be Worried One Bit If My Baby Throws Up?

Most newborns in the world, especially in their first few years, vomit from time to time. Things like indigestion, prolonged crying, or coughing can trigger this.

The most common reasons that children could be throwing up include:

  • GERD
  • Digestion difficulty
  • Stomach flu
  • Bacterial infections – chest infection, UTI, ear infection
  • Food allergy/lactose intolerance
  • Food poisoning
  • Motion sickness

Just keep in touch with your pediatrician as he/she can guide you in treating the reason behind your baby throwing up.

Having your baby’s medicine supplies at bay may also help you deal with your worries during an emergency.

These conditions are usually nothing that should spark panic in moms out there, as these conditions can heal soon enough and at home. 

More importantly, keep your baby’s fluids up to prevent dehydration.

When Should I Take My Baby to the Doctor for Vomiting?

How can a mother determine whether her child’s vomiting is normal or not?

If your little one experiences one of these warning signs and complications, it’s time to head to your local doctor/pediatrician right away:

  • Constant, forceful barfing
  • Greenish or yellow vomit
  • Diarrhea
  • Persistent/a lot of blood in the vomit
  • Blood in diaper
  • Signs of dehydration
  • Refusing to feed
  • More tired
  • Swollen tummy
  • Throw ups lasting longer than 1-2 days
  • Fever

Should I Feed My Baby Again After Vomiting?

How soon should you feed children after they throw up? Just about every mother at home has wondered this.

The most important thing you should worry about is keeping your baby hydrated after they vomit.

If your baby is hungry and takes the bottle or the breast after just throwing up, you can go right ahead and feed them. HOWEVER, note that this is the case for minor spit-ups and vomits ONLY.

Start with small amounts of feeding first and wait to see if they vomit again. If they don’t, you’re good to go. But if they do, then it’s better to wait.

If your little one doesn’t want to feed after throwing up several times, give them small amounts of liquid (preferably an oral electrolyte solution like Pedialyte) every 15-20 minutes to help keep them hydrated.

It’s also important to note that your children may benefit from medication or taking in nothing first if they are throwing up because of the following experiences:

  • Motion sickness
  • Earache
  • Fever

For severe cases of vomiting, it is a clinical practice to completely avoid feeding your baby for 4-6 hours to give their bowels a rest.

Introducing foods or liquids to your baby’s stomach during severe vomiting cases can do more harm than good!

For severe cases like this, it would be best to consult with your pediatrician on the best course of action.

However, severe cases would usually require you to bring your baby to the hospital, so keep that in mind if ever you’re in this situation.

At What Age Does Baby Spit Up Stop?

Infants are likely to spit up (yellow) until they can sit up on their own, which usually occurs around the age of 7 months.

However, many children tend to have fewer occurrences of spit-up when they reach 12 months/one year of age, around the same time in their life that they’re introduced to solid food at home.

If your baby’s conditions around yellow spit-up don’t improve after this period of time, the FINAL option is to consult your pediatrician/doctor.

In Conclusion

Woman cradling baby with spit-up

A yellow spit-up is one of the many normal occurrences in a baby’s life. When you see your baby is spitting up yellow, there are multiple reasons behind it, not necessarily pertaining to a serious case.

As a mother, you can take certain steps that work to reduce spitting up yellow. 

If you’re unsure about the vomiting or spit-ups of your little one, it’s always best to check with your doctor/pediatrician.

It’s best to do this ASAP before all the yellow starts building up!

FINAL TIP: Another common thing parents worry about is Sudden Infant Death Syndrome. If you want to know more about it, you can check out our guide on when you can stop worrying about SIDS.


September 14, 2022 – minor content edits

July 27, 2022 – Added 1 new article link

July 22, 2021 – Reviewed and updated article links

About the author

Angelica Graham

A few years ago, Angelica found out about all the plastic and toxic ingredients that got into most children’s products. And this worried her to no end. Because of this, she began to research what the best ingredients and materials were for children and made it her mission to share this information with other mothers.