Reflux, Colic or Milk Intolerance? How to Spot the Difference

When feeding isn’t going well or becomes a challenge, it’s natural for parents to then wonder whether it's something more! Reflux? Colic? Lactose intolerance?

The challenge is that many of these conditions share similar symptoms, making it difficult to tell apart. In many cases, these behaviours are also common parts of normal baby development.

In this guide, we’ll explain the differences between reflux, silent reflux, colic, lactose intolerance and cow's milk allergy, helping you understand the signs to look out for, when to seek medical advice and why it's best to speak to a healthcare professional before making feeding changes.

Here's a simple overview of some common baby feeding concerns:

• Reflux: Milk flows back up from the stomach, causing frequent spit-up or vomiting, during or after feeds.
• Silent reflux: Similar to reflux, but the milk is swallowed back down instead of being spat out, so symptoms can be harder to recognise.
• Colic: Episodes of frequent, prolonged crying in an otherwise healthy baby, often with no obvious cause.
• Lactose intolerance: A difficulty digesting lactose (the natural sugar in milk). This is different from an allergy and is uncommon in young babies.
• Cow's milk allergy (CMA): An immune reaction to the proteins in cow's milk that requires medical assessment and should not be self-diagnosed.

Many symptoms overlap, so it's important not to assume your baby has one of these conditions based on a single symptom.

If your baby has blood in their stool, difficulty breathing, swelling, persistent vomiting, poor weight gain or seems seriously unwell, seek medical advice immediately.

Reflux, Colic or Milk Intolerance: Quick Comparison Table

What Is Reflux in a Newborn?

Reflux is very common in young babies and affects up to 40% of infants. It occurs when the muscle at the base of the food pipe is still developing, allowing stomach contents, including milk and acid, to travel back up towards the mouth.

Reflux usually starts before a baby is eight weeks old and improves as the digestive system matures, usually disappearing by the time a child reaches 12 months.

Common reflux symptoms

Signs of reflux include:

• Bringing up milk or being sick during or shortly after feeding.
• Coughing, hiccuping or gulping while feeding.
• Arching the back or turning away during or after feeds.
• Crying or becoming unsettled after feeding.
• Slow weight gain if milk isn't kept down (though many babies with reflux gain weight normally).

If your baby is happy, gaining weight and not overly distressed, reflux often doesn't require treatment and will improve naturally with time. You can also read more about managing reflux on the NHS website.

What Are the Signs of Silent Reflux in Babies?

Silent reflux is similar to standard reflux, but instead of bringing up milk, the baby swallows it back down. Because there is no obvious spit-up, silent reflux can be harder to spot.

Signs of silent reflux may include:

• Gulping or swallowing hard between feeds.
• Coughing, spluttering or clear discomfort after feeding.
• Sour-smelling breath.
• Distress or crying when laid flat.
• Refusing to feed despite showing signs of hunger.

What Is Colic?

Colic is defined as excessive, frequent crying in a baby who is otherwise healthy and well-fed. It is very common, affecting up to 1 in 5 babies. Colic usually starts within the first few weeks after birth, peaks at around six weeks, and gradually resolves by three to four months of age.

Common colic symptoms

Babies with colic often:

• Cry intensely, often in the late afternoon or evening.
• Clench their fists, arch their back or pull their legs up to their chest.
• Have a red or flushed face while crying.
• Seem difficult or impossible to soothe.
• Pass wind or have a rumbly tummy during crying episodes.

While colic can be very stressful for parents, it is temporary and does not cause long-term harm to your baby.

What Are Lactose Sensitivity Symptoms in Infants?

Lactose intolerance happens when the digestive system produces less lactase, the enzyme needed to break down lactose, which is the natural sugar found in breast milk and cow's milk formula.

True lactose intolerance is relatively uncommon in young babies, as most produce plenty of lactase. It more frequently occurs temporarily after a stomach bug, which is known as secondary lactose intolerance.

Symptoms of lactose intolerance include:

• Loose, watery or frequent stools.
• Abdominal bloating and excessive wind.
• Tummy discomfort or grumbling after feeds.
• Nappy rash caused by acidic stools.

Milk Allergy vs Lactose Intolerance: What's the Difference?

It’s common to confuse lactose intolerance with cow's milk allergy (CMA), but they are two very different conditions:

Possible signs of Cow's Milk Allergy (CMA)

A baby with CMA may experience a combination of symptoms affecting multiple body systems:

• Skin reactions: Eczema, rashes, hives or swelling of the lips/face.
• Digestive issues: Vomiting, severe reflux, chronic diarrhoea or blood/mucus in the stool.
• Respiratory symptoms: Wheezing, persistent coughing, or a runny nose.

If you suspect your baby has a cow's milk allergy, do not self-diagnose or switch to specialized formulas without consulting a doctor or dietitian.

Should You Change Formula for Reflux, Colic or Suspected Intolerance?

When your baby is unsettled, it’s tempting to switch formulas right away. However, changing formulas too frequently can upset your baby's delicate stomach further and make it harder to figure out what’s actually causing their discomfort.

Conditions like reflux and colic are developmental and often improve on their own with time. Before switching formula, always discuss your concerns with your health visitor or GP. They can advise whether a formula change is necessary or if practical techniques might help instead.

What If Your Baby Is Breastfed?

Breastfed babies can also experience reflux and colic. If you are breastfeeding, symptoms rarely mean you need to stop. In most cases, adjusting positioning, ensuring a good latch, or getting support from a lactation consultant or health visitor can significantly help.

If a cow's milk allergy is suspected in a breastfed baby, a doctor may advise the mother to remove dairy from her own diet under medical supervision.

What to Try Before Changing Formula

Simple adjustments can often ease symptoms of reflux or colic without needing to alter your baby's diet:

• Paced bottle feeding: Keep the bottle horizontal to let your baby control the milk flow and prevent overfeeding.
• Keep baby upright: Hold your baby upright during feeding and for 20–30 minutes after feeds.
• Burp regularly: Pause during feeds to wind your baby gently rather than waiting until the end.
• Smaller, more frequent feeds: This reduces pressure on the stomach.
• Soothing techniques: Use gentle rocking, warm baths, skin-to-skin contact, or white noise to help calm a colicky baby.
• Check teat size: Ensure the teat flow isn't too fast, which can cause gulping and excess air swallowing.

Using Kendamil and Need Support?

If you're using Kendamil formulas and have questions about your baby's feeding, our customer care team is always here to support you. Contact us at enquiries@kendamil.com for friendly guidance.

You can also check out our dedicated guides on Let's Learn About Colic and My Baby Has Reflux – What Would You Recommend?.

Summary

Reflux, colic, and milk intolerances can feel overwhelming, but understanding the differences can help you navigate feeding challenges with confidence. Remember:

• Reflux and colic are common, normal parts of baby development that usually resolve on their own.
• Lactose intolerance is rare in healthy young infants, while CMA involves an immune response requiring medical guidance.
• Avoid switching formulas repeatedly without professional support.
• Try practical techniques like upright positioning, burping, and paced feeding first.
• Always speak to a GP or health visitor if you're concerned about your baby’s wellbeing, symptoms, or weight gain.

FAQs