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baby spitting up curdled milk

Mom’s question:
My baby boy is 5 weeks old. He is eating 4 oz every 3-4 hours. He is spitting up a lot. He was on breast milk, but after he was spitting up what looked like curdled milk his doctor said to try formula. He is doing the same thing, so switching to formula didn’t help at all. I’m not sure what to try now?

Brandi (Sparr, FL)

Baby Helpline:

Baby Spitting Up Curdled Milk, Normal Or Not?

Hi Brandi,

I wonder if maybe you and the doctor have misunderstood each other.

The milk becomes curdled when mixed with the acidic stomach fluid. So a baby spitting up curdled milk in itself is completely normal and not a problem. Many young babies spit up a bit of curdled milk now and then.

Whether the milked is curdled or not is more a matter of how quickly they spit up after feeding! If the baby swallowed the milk, and it mixed with the stomach fluids, it will come back up curdled. If your baby spat up immediately after swallowing, the milk will come back up just like regular milk.

But curdled milk in combination with very frequent vomiting may be a sign that something is not completely right.

Here are a few possible reasons for excessive spitting up  of curdled milk:

1. Intolerance

Your boy may have an intolerance to for example lactose or milk protein. If this is the case, then switching to some formula will not help at all unless you give him a special formula that caters to these problems.

Two possible types of formula that may work are hydrolysate formula, which is hypoallergenic and most often tolerated by babies with milk protein allergy, or low lactose formula, which can help your baby if he is lactose intolerant. (Links to Amazon, where you can check them out.)

However, it is entirely possible to continue breastfeeding a baby who is allergic to cow’s milk! All you have to do is to eliminate cow’s milk from your own diet.

2. Acid reflux

He may suffer from acid reflux. This is quite a common condition among newborn babies, where the gastric juices containing acid can travel back from the stomach into the throat – painful.

Switching to formula can sometimes help slightly since the formula is a bit thicker than breast milk. This is probably why the doctor suggested it. But it is a fairly minor difference – or no difference, as in your case!

Instead of quitting the breastfeeding, which obviously has a lot of benefits, try things like not feeding your baby too much at the time, feeding him in an upright position, avoid foods (for you if you breastfeed) that can aggravate reflux such as citrus, tomatoes, fatty foods, spicy foods, and carbonated drinks.

You’ll find several tips for feeding a baby with reflux in this thread.

Learn more about foods to eat and avoid while breastfeeding here.

There is also some medication available for severe acid reflux.

Obviously, no one can tell if your baby does have reflux without examining him and there may be other reasons for his spitting up. You can find Q& As of many related situations here when babies spit up a lot.

3. Pyloric Stenosis

Pyloric Stenosis is a condition where the outlet of the stomach is too narrow for the foods to travel over into the intestines.

Projectile vomiting of milk that may or may not be curdled, weight loss, and constipation are some of the signs of pyloric stenosis.

This condition needs treatment and surgery. (You can read more about pyloric stenosis at

This is not a full list, of course, but some examples. It may very well also be that nothing is wrong with your baby and that he simply is a baby who spits up a bit more than the average infant. If he is gaining weight and doesn’t appear to be in pain, he is likely to be fine.

Warning Signs of Excessive Spitting Up in Babies

The reason I way that the doctor and you may have misunderstood each other, is that it should be the excessive spitting up rather than the curled milk that is the main problem.

Here are some indicators from Mayo Clinic of excessive spitting up in babies:

  • Your baby isn’t gaining weight
  • The spit ups are forceful, more like real vomiting
  • The spit up contain green or yellow fluid
  • Your baby spits up blood or a material that looks like coffee grounds (which is likely to be blood, and in this case you need to take your baby to a doctor immediately)
  • Your baby refuses to eat repeatedly
  • There is blood in his or her poop
  • Your baby has difficulty breathing or other signs of illness (again, call the Dr or an ambulance, depending on the situation)
  • Spitting starts late – at age 6 months or older (this could, for example, be due to a food intolerance)
  • If your baby cries a lot –  for more than three hours a day and is more irritable than normal
  • Shows signs of dehydration and has fewer wet diapers than usual

I think you should take him back to his doctor (or maybe to another one if you don’t think you get enough support from this one).

Simply telling you to stop breastfeeding is not, in my opinion, good advice. And you need to understand what the Doctor actually thinks is the problem.

There are not many reasons to think that quitting breastfeeding would solve the problem (as you have already noticed), and while the formula is a good substitution for breastmilk, it is still a substitution and several of the benefits of breastfeeding will be missed.

Good luck!

Hey, parents, do you have experience of babies spitting up curdled milk? Please help this mom by commenting below! Or share your own thoughts and worries!

This Post Has 4 Comments

  1. Avatar

    My daughter spit up all the time when she was
    first born until about 8 months. I only breast fed, and I was worried
    she was spitting up almost everything that was going in. We found the
    problem to be reflux, and although she continued to spit up after the
    medicine it wasn’t as much. Once you start her on foods she will be
    better, but don’t stop breastfeeding!!

  2. Avatar

    I think it’s very sad that a professionally
    trained person such as a doctor would tell a mother not to breastfeed
    her child because of spitting up. There are many factors…such as a cow
    milk intolerance in your milk…so you would need to cut out diary

    Since you changed from breastmilk to formula…then the problem
    would not stop there because formula is made mostly from cow milk. I
    would advise switching back to breastmilk which can help your child
    recover inside and out when dealing with problems in this big world such
    as allergies. If you do not plan to switch back i would suggest a goat
    milk formula base (goat milk digests in the human system within 2-4
    hours…cow milk takes 8 and more) or at least try an organic formula or
    soy based. Although these can be a little more, your baby would greatly
    benefit from it.

    Good luck and my advice it to find another
    pediatrician! It has been medically proven for a very long time that
    breast milk is what was designed for the infants ultimate help and
    support during life. Babies do not even develop an immune system alone
    for the first 6 months of life, they rely on yours to fight for them
    during that time. Good luck!

  3. Avatar
    Just me

    Okay, if the baby is spitting up a lot I
    would take the formula down a little bit like to 3.5 oz. My babies are
    almost 4 months old and take 4 oz. every three hours. I do believe that
    is too much for a five week old. Good luck!

  4. Avatar

    .My baby is 3 month old.In his 2nd month he used to strain and cry,doc said he has colicaid for which doctor has prescribed colicaid.That helped.Recently 2 weeks back he vomited curdled milk and at times it used to be mixture of water and curdled milk or at times just water.Doc said he has reflux nd prescribed Domstal 1.5 ml 4 times a day for 5 days but i jst gave him for 2 days cos he seemed better.But since yesterday he is throwing up again. 🙁

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