Raising a baby is challenging enough without added worries like feeding struggles, digestion issues, or disrupted sleep. When your little one is fussy during feeds, has trouble with their tummy, or isn’t sleeping well, it’s only natural to feel stressed and overwhelmed as a parent. But did you know that many of these issues could be signs that your baby isn’t tolerating their formula?
If you’re noticing ongoing symptoms and wondering whether it’s time for a change, keep reading. In this post, we’ll explore the most common signs of formula intolerance, what they could mean, and what steps you can take to help your baby feel more comfortable and nourished.
What are some signs that the formula is working well
Before we explore signs of intolerance, it’s helpful to recognise when a formula is actually working for your baby. When a baby tolerates their formula well, you’ll often see consistent signs of comfort, health, and growth.
These signs may include steady weight gain, regular soft bowel movements, and contentment between feeds. Your baby may seem settled after eating, sleep well, and have clear, healthy skin. These are all reassuring indicators that your chosen formula is being well digested and meeting their nutritional needs.
Here are some healthy signs:
- Steady weight gain
- Regular soft bowel movements
- Good sleep
- Clear, healthy skin
Now let’s look at some signs that your baby’s formula may need to be changed.
Signs your baby isn’t tolerating their formula
1. Excessive Fussiness
Some level of fussiness is completely normal in babies. Crying, restlessness, or needing extra comfort are all part of early development. However, if your baby becomes noticeably more fussy than usual, especially around feeding times or shortly afterwards, it may be a sign that something isn’t right.
Persistent fussiness could mean your baby is still hungry or not getting enough nutrition from their current formula. It might also suggest discomfort, pain, or difficulty digesting the milk. When this behaviour is combined with other signs, such as gas, bloating, or poor sleep, it could indicate a sensitivity or reaction to the formula.

2. Digestion
Digestive issues are one of the most common signs that your baby’s formula might not be right for them. If your baby struggles to process certain ingredients, it can lead to discomfort, tummy pain, or disrupted feeding and sleeping routines. This may be caused by sensitivities, allergies, or conditions such as lactose intolerance or cow’s milk protein allergy.
If you’re concerned, it’s always best to speak to a healthcare professional. They may suggest switching to a different formula, such as one made for sensitive digestion or a comfort blend. Baby’s Pantry offers several gentle options, including formulas for colic, constipation, and plant-based feeding, to suit different needs.
Diarrhoea and Constipation
It’s normal for your baby’s bowel habits to change as their digestive system develops. However, frequent diarrhoea after feeding could be a sign that the formula isn’t sitting well. Loose stools, especially if they continue over several days, may lead to dehydration and discomfort.
Constipation can also be a sign of trouble. If your baby is passing hard, dry stools or straining to go, it might be related to their current formula. In both cases, a change may help relieve symptoms and support healthier digestion.
Gas and Tummy Pain
Increased gas is another possible sign of formula sensitivity. Look out for signs such as a bloated belly, frequent burping or flatulence, tummy gurgling, or your baby pulling their knees up as if in pain. These symptoms often appear shortly after feeds and may indicate that your baby’s formula is causing discomfort.
3. Sleeping Problems
Babies who are uncomfortable, in pain, or still hungry may struggle to settle or stay asleep. If your baby is waking frequently, crying during the night, or having difficulty falling asleep after feeding, it could be a sign that their formula isn’t working well for them.
These sleep disturbances may be linked to digestive discomfort, gas, or abnormal bowel movements. In some cases, they can also be related to an allergy or sensitivity, such as a cow’s milk protein allergy. This can be difficult to spot, but poor sleep alongside other signs like fussiness or skin irritation may indicate an issue.
If you suspect an allergy or sensitivity, it’s best to speak with your healthcare provider. Depending on their guidance, you might consider switching to a more gentle formula, such as one made with goat’s milk or a hydrolysed option for sensitive tummies.

4. Rashes
Babies have extremely delicate skin, which can easily react to changes in their environment, diet, or temperature. Formula can sometimes play a role in skin reactions, especially if your baby has an intolerance or allergy to certain ingredients.
One of the more common causes is a cow’s milk protein allergy. This can trigger skin-related symptoms such as hives, eczema, or general redness. You might also notice other signs like sneezing, a runny nose, vomiting, or digestive discomfort. These symptoms can range from mild to more severe.
It’s important to remember that conditions like eczema, reflux, colic, and diarrhoea are common in infants and aren’t always linked to an allergy. Cow’s milk allergy is just one possible explanation among many, so it’s worth speaking to a healthcare professional if you’re unsure.
In rare cases, a cow’s milk allergy may cause anaphylaxis, a severe allergic reaction that requires immediate medical care.

5. Vomiting
Spitting up is a normal part of infancy and happens regularly, even in healthy babies. It often looks like milk coming up effortlessly during or shortly after a feed. This is known as posseting and usually improves as your baby grows.
However, vomiting can sometimes signal a problem, particularly if it happens frequently or appears forceful. If it seems like your baby is trying to get rid of something or they are distressed during or after feeds, this could point to an intolerance or allergy to certain ingredients in their formula.
Normal spit-up is usually mild and not uncomfortable for your baby. But if you notice forceful vomiting, frequent episodes, or any signs of pain, it’s worth speaking to a healthcare professional for guidance.

How to choose the right formula
Choosing the right formula depends entirely on your baby’s specific needs, symptoms, and how they respond to feeding.
The first step is to identify what might be causing discomfort or intolerance. This often means tracking your baby’s symptoms and discussing them with a healthcare professional. They can help determine whether your baby has a sensitivity, such as trouble digesting lactose, or an allergy like cow’s milk protein allergy.
If your baby does have a confirmed cow’s milk allergy, switching to a goat milk formula may help. Goat milk contains different proteins that some babies find easier to digest. Brands like Kendamil, Holle and Jovie offer goat milk formulas that are designed to be gentle on the stomach.
If your baby does not have an allergy but seems to experience digestive sensitivity, such as gas, colic, or constipation, a comfort formula may be more suitable. These formulas are designed to be easier to digest and often contain partially broken-down proteins or reduced lactose.
Every baby is different, so finding the right formula can take time. With support from a healthcare provider and close attention to your baby’s symptoms, you can find an option that supports their comfort, growth and wellbeing.
Conclusion
There are several signs that may indicate your baby isn’t tolerating their current formula. While symptoms like vomiting or fussiness on their own are often normal, a combination of issues such as forceful vomiting, skin reactions, digestive problems or sleep disturbances may suggest an intolerance or allergy. If these symptoms persist, it could be time to consider changing your baby’s formula.
At Baby’s Pantry, we offer a wide selection of formulas tailored to different needs. For babies with cow’s milk protein allergy, you might want to explore goat milk options from Kendamil, Holle or Jovie. We also stock Kendamil Comfort Milk, which is designed to be gentle on sensitive tummies, along with other formulas that support easier digestion and feeding comfort.