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  • Switching Baby Formula: Guidelines on How Not to Harm Your Infant

    by Agustina Fernandez January 25, 2024 9 min read

    Switching Baby Formula: Guidelines on How Not to Harm Your Infant

    You may have noticed changes in your little one. If frequent gas, spit-ups, and constipation ring a bell, then you’re probably wondering if your baby’s formula might be the culprit.

    While it’s true that sometimes your baby may need a different formula, the symptoms mentioned aren't always health concerns. Digestive issues are common in babies, making it hard for parents to decide if a formula change is necessary.

    Red flags to watch out for include extreme fussiness, severe constipation, diarrhea or bloody stool, excessive spit-up or forced vomiting, and allergy symptoms. These could be signs your baby may not tolerate their formula. If you suspect this, seek professional medical advice.

    Generally, a new brand of the same kind of formula (i.e hypoallergenic formulas, goat’s milk formulas, etc.) will have the same basic ingredients as your baby's current formula. So if you want to try out different brands of the same type of formula, it’s generally not a problem. That being said, it's always best to consult your pediatrician first before making any changes.

    For big changes—like switching from a lactose-free formula to a goat's milk formula—do so carefully and with your child’s doctor’s guidance.

    If you’re curious whether a different formula would be better for your baby, read on for a crash course in switching baby formula!

    Normal Symptoms During Infancy

    Infants experience lots of normal bodily activities that can appear concerning. Learning about what's normal for your baby and how to tell if their formula is tolerated well is important.

    During infancy, parents will likely notice their little one spitting up now and again. This is because babies have an immature digestive system. Combined with all the time that they spend on their back, it’s hardly surprising that milk sometimes finds its way back up.

    Constipation is common. Most infants have at least one bowel movement a day, but going up to two days before passing a stool isn’t unusual. Because young babies have underdeveloped abdominal muscles, they may strain and fuss during a bowel movement.

    Finally, babies are almost certain to experience gas, this happens when too much air is swallowed from crying or bottle feeding. While gas can certainly cause your little one discomfort, as they continue to grow and their digestive and abdominal muscles have more time to develop their bodies will be better equipped to handle it. 

    normal digestive issues in infancy | Organic's Best

    The fundamental role of baby formula is to support normal growth and development in your baby. Some good indications that baby formula is fulfilling its job are:

    1. Regular bowel movements: 1 to 2 per day and a minimum of five wet diapers a day

    2. Hitting growth milestones: gaining weight appropriately for their age

    3. Generally good demeanor: feeling relaxed and satiated after eating 

    If these are met, your baby is probably fine with their current formula!

    How to Tell When Your Baby Needs to Switch Formula

    Occasional fussiness, gas, and diarrhea are to be expected. However, if any of these normal symptoms crosses the line into being excessive, then you’ve got cause for concern. 

    signs your baby may need a new formula | Organic's Best

    Extreme Fussiness

    A change in demeanor is nothing short of alarming to parents but being a baby is not always a cakewalk, it can be hard to adjust to a new world outside the womb. Anything from a dirty diaper, to overstimulation, hunger, or temperature sensitivity can bring about fussiness.

    If fussiness is inconsolable and occurs during or after drinking formula, the formula may be the issue.

    Severe Constipation

    As we already know, constipation in babies happens from time to time, so going up to two days without a bowel movement is generally nothing to be worried about. If your baby is always straining, has very infrequent bowel movements, experiences painful stomach cramps, and passes small hard stools, a formula switch may offer relief.

    Learn more: What's the Best Baby Formula for Constipation?


    If not enough water is mixed into a powdered formula or infant formula concentrate, it can lead to diarrhea and dehydration. However, if you know you’ve prepared everything correctly and your baby is regularly having diarrhea following feedings, it could be that they need to switch formulas.

    Bloody Stool

    Though it’s not a pretty sight, it's important to pay attention to your baby’s stools as an indicator of their health. Bloody stools can be a sign that your little one has a cow's milk allergy. Blood in the stool can also be the result of many other health issues so be sure to consult your baby's pediatrician to get to the root cause.

    Excessive Spit Up and Vomiting

    Spitting up from time to time isn’t an issue as long as your baby is hitting growth milestones and needs a diaper change every six hours or so. If after each feeding, your baby produces over two tablespoons worth of spit-up, this could indicate formula intolerance.

    If beyond just spitting up, you notice that your baby is throwing up forcefully to rid their body of formula, this is a cause for concern. Not only is your baby's discomfort a problem, but vomiting prevents your baby from getting essential nutrients from their formula. When this happens, reach out to your child's doctor right away.

    Allergy Symptoms

    In the first few months of life, around 2-3 % of babies end up developing an allergy to cow’s milk (although thankfully many will outgrow it). Cow’s milk protein allergy happens when your infant's immune system has an abnormal reaction to the proteins found in cow's milk formula.

    Though most babies with allergies are afflicted by a cow’s milk allergy, other infants may react to soy formula and formulas that contain corn starch. Usually, an allergy or intolerance is caused by the milk or soy proteins present in cow’s milk and soy-based formulas. It’s very rare for a baby to have lactose intolerance.

    If your little one has an allergy or intolerance to their infant formula symptoms will arise between feeding and up to 10 days later. The signs of an allergic reaction include… 

    • Wheezing
    • Hives
    • Vomiting
    • Loose or bloody stools
    • Skin rashes or eczema
    • Swelling
    • Anaphylactic shock 

    Learn more: How to Prevent the Development of Food Allergies in Babies

    Make sure to contact your pediatrician as soon as you notice these symptoms.

    Learn more: Signs Formula Doesn’t Agree With Baby

    When to Switch to Sensitive Baby Formula

    If your baby experiences persistent fussiness, gastrointestinal problems, poor weight gain, or allergic symptoms, ask your baby's doctor if using a specialty formula is right. There is a range of sensitive formulas each designed to address babies’ specific set of symptoms. 

    Learn more: When to Use Hypoallergenic or Special Formula

    Partially Hydrolyzed Formula

    For babies with gas and fussiness, one formula option is a partially hydrolyzed formula. This infant formula helps aid digestion because of its gentle milk protein structure that has been broken down into smaller, more digestible pieces. However, these formulas are intended for sensitivities, not allergies. 

    Extensively Hydrolyzed Formula

    For babies with allergies, pediatricians will recommend avoiding foods that cause allergic symptoms. Hypoallergenic formulas are intended for babies at risk of allergies. Your pediatrician may suggest that you start your baby off with one of these formulas if you have a family history of food allergies or an older child with severe food allergies.

    Hypoallergenic formulas are made with extensively hydrolyzed milk. This means that the milk has been broken down一through a process called hydrolyzation一into its simplest molecular form. This process removes complex milk casein proteins leaving behind only a smaller and more digestible hydrolyzed whey protein that is low in allergens.

    A popular choice for parents looking to minimize the risk of milk protein or soy protein allergies in their infant is the HiPP Combiotic HA formula. This hypoallergenic formula has been tried and tested for more than 25 years and has helped in the realm of allergy prevention. 

    hipp ha baby formula | Organic's Best

    Board-certified pediatricians recommend one of two methods for switching your baby from their old formula to a new formula:

    1. Quitting the old formula cold turkey - An immediate switch in infant formula may be appropriate when your little one is switching formulas due to an allergy, intolerance, or medical condition.

    2. Switching formulas slowly - If your baby doesn’t have allergies, intolerances, or medical conditions, a slow transition will usually help give your baby’s tummy time to adjust to the change.

    Pediatricians recommend two methods for switching formula: immediately or slowly. For a slow transition, mix new and old formulas gradually until exclusively on the new formula. We’ve prepared a helpful guide on transitioning formulas for you below!

    how to transition to a new formula | Organic's Best

    Pro Tip: You can help minimize gas build-up during a formula switch by putting gentle pressure on your baby’s stomach 30 to 60 minutes after their feeding with either your hands or some tummy time.

    Can Switching Formula Hurt My Baby?

    If your baby's stool suddenly becomes very firm after feeding a new formula, they may be more constipated. This isn't an immediate cause for alarm, and can happen when switching formulas, since your baby's stomach is sensitive to changes.

    Switching formulas is safe if it's a last resort and with medical advice. Side effects like gas or a change in bowel habits are normal responses. Your baby needs time to adjust.

    While it’s true that switching formulas can lead to gas or a change in your baby’s bowel habits, both of these are fairly normal responses. Your little one needs time to adjust to their new formula and, in a short time, any cramps, gas, or diarrhea should go away.

    How Long Will Side Effects Last After Switching Baby Formulas

    Babies usually need up to 6 weeks to fully transition to a new formula. Contact your doctor if you have concerns about your baby's adjustment.

    side effecting of switching baby formula | Organic's Best

    While it can be tempting to give your little one a timeline for adjusting, a better strategy is to look out for and document any new symptoms. Keeping track of these changes and comparing it to your baby’s previous symptoms allows you to identify whether your baby is improving or not.

    If they haven’t improved after a week, it could be that they just haven’t adjusted yet or perhaps you haven’t yet found the right formula for your little one. If you don't see any sign of improvement at 3 weeks, it’s time to reach out to your baby’s pediatrician to make sure your baby is on the right track.

    How Long Does Diarrhea Last After Changing Formula?

    Diarrhea is normal during your baby's adjustment period to the new formula. It's no fun for your little one who may get tummy cramps and gas, and it’s also not fun for you who has to clean it up. Thankfully, most baby diarrhea clears up on its own within 24 hours without requiring treatment.

    Until the bout passes, it’s important to keep your baby comfortable and hydrated. If diarrhea becomes severe or persists past 24 hours, make sure to consult your child’s pediatrician.


    Parents are always on red alert for health complications in their little ones and babies often experience gastrointestinal issues making it easy to mistake a bit of gas or fussiness for legitimate health concerns.

    Combine that with the fact that every baby formula on the market boasts about its amazing nutritional value and it can be easy to view a formula switch as a quick fix to all your baby's problems. Unfortunately, this is infrequently the case.

    A switch in infant formulas can be stressful for your baby’s body, so it should only be done if you’ve exhausted all other options and you get the A-okay from your pediatrician. It's probably time for a change if you notice extreme fussiness, severe constipation, diarrhea or bloody stool, excessive spit-up or forced vomiting, and allergy symptoms in your little one.

    For babies with allergies, intolerances, or medical conditions, they’re usually good to start their new formula immediately. For all other babies, it's typically best to take it slow so they have adequate time to adjust to their new formula.

    And finally, remember that it can take up to 6 weeks for your baby to fully adjust to their new formula, so patience is a virtue! That being said, you should contact your doctor if you feel your child is not adjusting well to their formula.


    Please be aware that this information is based on general trends in babies, and it is not medical advice. Your doctor should be your first source of information and advice when considering any changes to your child’s formula and when choosing your child’s formula. Always consult your pediatrician before making any decisions about your child’s diet or if you notice any changes in your child.

    Breastfeeding is the best nutrition for your baby because breast milk provides your child with all the essential nutrients they need for growth and development. Please consult your pediatrician if your child requires supplemental feeding.

    Agustina Fernandez
    Agustina Fernandez

    Dr. Agustina Fernandez earned her medical degree from the prestigious Universidad Nacional de Córdoba, Argentina. With a deep-rooted passion for pediatrics, Dr. Fernandez is currently on the path to specializing in children's healthcare. Recently, she has delved into the vital field of infant nutrition. Her research interests include breastfeeding, infant formula, and baby food in little ones’ formative years. Dr. Fernandez's commitment to this area of study underscores her dedication to ensuring the health and well-being of children from their earliest days.

    2 Responses

    Organic's Best Shop
    Organic's Best Shop

    July 13, 2023

    Hi Lenore,

    Thank you so much for your feedback; we appreciate your support. Feel free to let us know if there are any topics you’d like for us to cover, and happy reading!

    Warm wishes,

    - Your Organic’s Best Team

    Lenore Ormiston
    Lenore Ormiston

    July 13, 2023

    To the admin, Your posts are always well organized and easy to understand.

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