FAQs can be found at the end of this blog. 

Seeing your baby cry or in discomfort is upsetting for parents when all they want is to help their little one. Conditions like colic and cow’s milk allergy can have some similar symptoms, so the first step for parents is finding out which their baby has. Vhi consultant paediatrician, Dr Caroline Lhopital, explains the differences and overlaps between the two, and what parents can do to help ease their baby’s discomfort. 

It can be difficult to distinguish between cow’s milk protein allergy and colic in a baby. This is because some of the symptoms can overlap and present similarly. A cow’s milk protein allergy is also different to a lactose intolerance, although the two are commonly confused. Let’s break down the facts about colic and cow’s milk allergy first, then have a look at what makes a cow’s milk allergy different to a lactose intolerance.

What is colic?

Baby’s colic is as old as humanity. Tablets in Ancient Mesopotamia were already offering advice for crying babies! [1]. Colic is the name we give to excessive and frequent crying in babies that otherwise appear to be perfectly healthy. It has no certain or identifiable causes, even now with modern medicine. Colic will affect up to 1 in 5 babies and will usually start when a baby is around two weeks old. It generally ends by four to six months of age and has no consequences on the baby’s future development whatsoever.

The official definition of colic is a baby that cries more than three hours a day, for more than three days a week, for more than three weeks. Babies with colic still thrive, grow, and gain weight as normal.

Crying is the only way your baby can communicate their needs. If your baby is crying it could mean that they’re hungry, need a nappy change, are too hot or want to be cuddled, for example. The crying will stop quickly once you find out what they need. If your baby is still crying when all their needs are met, visit your healthcare provider for guidance.

Colic crying is often more common in the evening time. Your baby’s cry will be loud and intense-sounding. If your baby has colic, they’ll be restless and fussy. When they cry, they might draw their legs up and arch their back, tense their tummy or clench their fists. Their faces will go red as they cry, and it can be difficult to soothe them. They tend to swallow a lot of air when crying, and would often have gas, but this is more a consequence than a cause of colic. It’s a very upsetting situation for parents, as we are hard-wired to respond quickly to a baby that seems in distress and can feel quite powerless to calm a baby with colic.

Treatment for colic

There is no treatment for colic but there are things you can do to try soothing your baby: hold them close when they cry, gently rock them, give them a warm bath or gently massage their tummy in circular motions. Those methods don’t work consistently, and what worked one day might not be working the next ─ this is common with colic and not a reflection on your parenting skills. The most important thing is that an adult is there, caring and supporting your baby while they cry.

That adult doesn’t have to be you, and it’s sometimes necessary to ask for help from family members to help care for a colicky baby while you recover. Using ear plugs can help you keep your sanity while still being present for your baby. It may be helpful to avoid over-stimulation for babies with colic; keep loud noises, busy spaces or bright lights to a minimum when they’re distressed.

Feeding a baby with colic

Depending on whether you formula feed or breastfeed your baby, there are some considerations to keep in mind if they have colic.

If you breastfeed your baby:

• Try emptying your milk in one breast during a feed before you change to the other breast. When breastfeeding, you create two types of milk. Foremilk, which comes out first, is good at relieving thirst, but is rich in sugars that can ferment and cause gas. The second half of your milk (sometimes called hindmilk) has more fat content. Fat slows down digestion, and this can help with your baby’s discomfort. It is important for the baby to get both types of milk during one feed.
• Avoid drinking tea, coffee and any other drinks that have caffeine.

If you formula feed your baby:

• Try to minimise the amount of air in the bottle when you feed them.
• Feed your baby in the correct position, sitting upright in your lap or supported by your arm, with the bottle in a horizontal position so the teat is full of milk.
• Wind or burp them afterwards.

Probiotics or herbal remedies can sometimes offer some modest comfort for colicky babies. Speak to your healthcare provider before starting them, and don’t hesitate to stop them if you don’t see any improvement.

Let’s move on from colic to cow’s milk allergy to better understand the symptoms they have in common.

Cow’s milk allergy

Cow’s milk allergy is caused by your baby’s immune system reacting to the proteins found in cow’s milk. Most formulas are made using cow’s milk, and even if the protein is treated to make it more digestible for babies, it would still be recognised as coming from a cow. Breast milk contains mainly human proteins, but if the parent drinks cow’s milk, a small quantity might end up in the breast milk.

Symptoms of cow’s milk allergy include gut issues (bloating, tummy pain, gas, diarrhoea, vomiting), skin rash, and/or respiratory problems (wheezing, coughing or chestiness). Weight gain is usually slow.

As you can see, some symptoms are quite similar to colic: discomfort, crying, restlessness, and tensing their tummy. But, if your little one is experiencing the other symptoms above, such as vomiting, diarrhoea or skin problems, it might be an indication of a cow’s milk allergy. Your healthcare provider will be able to guide you on diagnosis and treatment.

Treating cow’s milk allergy

If your baby has a cow’s milk protein allergy, the management of the allergy will vary depending on whether your baby had an immediate allergic reaction (symptoms start within minutes and up to two hours after eating the allergen) or a delayed allergic reaction (symptoms start two hours up to 24 hours after eating the allergen), and whether they are breastfed, or formula fed.

If your baby had an immediate allergic reaction to cow’s milk (immediate widespread rash, vomiting, swelling of the face and breathing issues), no matter if they are breastfed or formula fed, stop giving them the milk straight away and reach out to your healthcare provider for next steps.

Delayed allergic reactions tend to cause symptoms that are closer to colic. If your baby has a delayed allergic reaction and is formula fed, they will be given a prescription formula by their healthcare provider; this prescription milk is specially formulated and is the only formula recommended for the treatment of cow’s milk protein allergy in infants aged under 12 months. Vegetable milks are not recommended as a replacement for this age group. Other mammal’s milks (such as goat’s milk) have a 70% risk of causing the same issues (called cross-reaction) and are not recommended for proven cow’s milk allergy treatment.

The first-line prescription milk is called ‘extensively hydrolysed formula’. The proteins in milk that cause the problems for your baby are broken down into small particles in this prescription milk, so they won’t cause an allergic response and can be better handled by your baby’s gut. In rare cases, some babies will need milk with its proteins broken down even smaller, into amino acids. Both milks need to be prescribed with the guidance of your baby’s healthcare provider.

Most milk allergies in babies are temporary. Milk-allergic babies will remain on special formula for some time, and then gradually (at weaning stage), we’ll start re-introducing the cow’s milk (with the support of a dietician) by following what’s known as the ‘milk ladder’. We start with cooked or processed milk, which causes the protein to be changed and become less irritating for your baby’s gut. Foods on the bottom of the ladder would include biscuits or breads. As you climb the ladder, the milk is less processed, and your baby begins to tolerate this over time. Your baby can be brought back down a step on the ladder for a time if needs be, until they can progress with less processed milk and have no allergy symptoms.

For breastfed babies with delayed allergy symptoms, it’s sometimes recommended that the breastfeeding parent remove cow’s milk from their diet for a period decided with their healthcare provider. Since the cow’s milk quantities passing through breast milk are quite small, it can usually be reintroduced after some time, once your baby’s symptoms have improved. If dairy exclusion lasts for more than two weeks, appropriate dietary supplementation needs to be considered throughout the exclusion trial, to make sure that both mother and baby receive the correct level of calcium, iodine and vitamin D.[2]

Next, I’ll speak briefly about lactose intolerance so we can see how it differs from a cow’s milk allergy. It’s understandable why people confuse the two, as cow’s milk causes uncomfortable symptoms for both. But, with a lactose intolerance, goat and sheep milk also cause issues.

What is a lactose intolerance?

Having an intolerance to lactose is not the same as having a cow’s milk allergy. Lactose is the sugar, or carbohydrate, found in milk (cow, sheep, goat and even a human’s milk). It’s not recognised by the immune system but digested by enzymes in the lining of our gut. When you’re intolerant (missing the enzyme), your body can’t properly digest it, causing symptoms like bloating, discomfort, gas, and diarrhoea.

The type of lactose intolerance we see most commonly in babies is called secondary or transient lactose intolerance, and it’s temporary. It’s usually triggered after a baby has had a viral infection, and their gut lining is inflamed, causing the enzyme to not work properly. We would usually place them on a lactose-free milk for about six weeks until their gut is healed. When they grow, some people lose that enzyme entirely and might develop lactose intolerance later in childhood or adulthood.

If you think your baby is having discomfort after consuming milk, it’s best to speak to your healthcare provider to get a diagnosis first, before switching formulas. This is just in case it’s something other than a lactose intolerance at play.

When to see your healthcare provider

Symptoms like diarrhoea, vomiting, stomach pain, and irritability are common for various conditions, including colic, reflux and cow’s milk allergy, so it can be a bit confusing for parents to know what the root cause is. Your healthcare provider will be able to examine your baby, listen to the story of their symptoms and behaviours, and figure out what’s causing the upset. They’ll then choose an appropriate care plan for your baby and work through this with you.

Here’s a checklist of instances when you should bring your baby to see your healthcare provider:

• You’re not sure if your baby has colic or why they’re crying more than is usual.
• They’re vomiting and it’s green. This means they’re bringing up bile.
• They’re projectile vomiting (forceful vomiting).
• There’s blood in their poo.
• They’re not feeding well.
• Their symptoms began after you introduced formula milk to their diet.
• They’re losing weight or not gaining enough weight.
• You’re worried about them.

Colic and cow’s milk allergy do have some overlapping symptoms, but reactions like vomiting, wheezing, coughing, and rash are indicators of cow’s milk allergy rather than colic. If your baby displays any of the symptoms I’ve discussed in this blog, visiting your healthcare provider is the first step. With their help, you’ll figure out what’s causing your baby discomfort and find the best path forward.

[1] https://atlasobscura.com/articles/crying-baby-in-mesopotamia

[2] Irish Food Allergy Network, https://www.ifan.ie/food-allergy-in-summary/pregnancy-and-breastfeeding/

FAQs about colic and cow's milk allergy

What is colic?

Colic is frequent, excessive crying in an otherwise healthy baby with no identifiable medical cause.

How common is colic in babies?

Colic affects up to 1 in 5 babies and usually begins at around two weeks of age.

When does colic stop?

Colic typically improves on its own and usually resolves by four to six months of age.

What are the signs of colic?

Signs of colic include intense crying for long periods, often in the evening, along with restlessness, tensing the tummy, drawing up the legs, clenching fists and difficulty settling.

Does colic affect a baby’s growth or development?

No. Babies with colic grow, gain weight and develop normally, despite the frequent crying.

Can feeding cause colic?

Colic is not caused by feeding, but feeding techniques can sometimes influence comfort. Trapped air during feeds can worsen discomfort, although it is not the underlying cause of colic.

Is colic the same as cow’s milk allergy?

No. Colic and cow’s milk allergy are different conditions, but their symptoms can overlap. Cow’s milk allergy usually also involves other symptoms such as vomiting, diarrhoea, skin rashes or poor weight gain.

This content is for information purposes only and is not intended or implied to be a substitute for professional medical advice, diagnosis, or treatment. Always seek advice from your GP or an appropriate medical professional if you have concerns about your health, or before commencing a new healthcare regime. If you believe that you are experiencing a medical emergency call 999 / 112 or seek emergency assistance immediately. 

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