Why Is My Baby Having Watery Stools After Switching to Lactose-Free Formula?

Drinking lactose-free milk powder can cause diarrhea?

Hello Doctor, my baby is currently one month and 24 days old.
Initially, we were using Abbott's hydrolyzed protein formula, but he had a bowel movement every two days and his stools were somewhat hard.
We then switched to Meiji's lactose-free hydrolyzed protein formula (it's been 3 days now), but his stools have become very loose, almost watery, with him having bowel movements 4 times a day.
Additionally, every time he passes gas, he also has a loose stool, and his anus is becoming red.
Why is it that after switching to lactose-free formula, my baby is experiencing this situation? Is this just a transitional phase after changing formulas? Can we mix Abbott's hydrolyzed formula with Meiji's hydrolyzed formula? Thank you, Doctor, for taking the time to respond.
^^

Fenfenhong, 30~39 year old female. Ask Date: 2016/01/08

Dr. Pei Rensheng reply Pediatrics

Hello, the purpose of lactose-free formula is to prevent diarrhea, and most babies do not experience diarrhea after consuming it.
It is more likely that the formula is not suitable (intolerance) for them, or they may coincidentally have gastroenteritis.
You can visit the hospital for a stool test to clarify the cause.
Wishing you health and happiness.
Sincerely, Dr.
Pei Ren-Sheng, Director of Pediatrics, Taoyuan Hospital, Ministry of Health and Welfare.

Reply Date: 2016/01/08

More Info

When a baby experiences watery stools after switching to a lactose-free formula, several factors may be at play. First, it's important to understand that lactose-free formulas are designed to be easier on the digestive system for babies who are lactose intolerant or have difficulty digesting lactose. However, just because a formula is lactose-free does not mean it will be suitable for every infant.
In your case, your baby was initially on a hydrolyzed protein formula, which is often recommended for infants with a higher risk of allergies or those who have shown signs of intolerance to standard formulas. The switch to a lactose-free hydrolyzed formula may have been made to address hard stools and potential discomfort. However, the change in stool consistency to watery and frequent bowel movements could indicate that the new formula is not being well tolerated by your baby's digestive system.

There are a few potential reasons for this reaction:
1. Formula Intolerance: Your baby may have an intolerance to the specific ingredients in the new lactose-free formula. While hydrolyzed formulas are designed to be hypoallergenic, some babies may still react to certain proteins or other components in the formula.

2. Adjustment Period: When switching formulas, it is common for babies to experience some gastrointestinal changes as their bodies adjust to the new ingredients. This adjustment period can last a few days to a week. However, if the watery stools persist beyond this period, it may be a sign that the formula is not suitable.

3. Underlying Gastrointestinal Issues: If your baby has an underlying gastrointestinal condition, such as a mild infection or inflammation, this could also contribute to changes in stool consistency.
4. Overhydration: If your baby is consuming more fluid than usual, this could lead to looser stools. However, this is less common with formula-fed infants, as they typically regulate their intake based on hunger cues.

Given that your baby is experiencing frequent watery stools and redness around the anus, it is advisable to consult with your pediatrician. They may recommend a stool test to rule out infections or other gastrointestinal issues.
As for combining the two formulas (the hydrolyzed protein and the lactose-free formula), it is generally not recommended to mix different formulas without consulting a healthcare professional first. Each formula has a specific composition, and mixing them could lead to further digestive issues or inconsistent nutrient intake.

In summary, while lactose-free formulas are intended to alleviate digestive discomfort for some infants, they may not be suitable for all. If your baby continues to have watery stools, it is crucial to seek medical advice to ensure they receive the appropriate nutrition and care. Your pediatrician can help determine the best course of action, whether that involves switching formulas again or investigating other potential causes for your baby's symptoms.

Similar Q&A

Is Lactose-Free Formula Safe for My Baby's Digestive Issues?

Hello, doctor. My baby is currently 11.5 months old, measuring 76 cm and weighing 10.5 kg. She is lively, cheerful, and active, showing good growth. However, we have been facing persistent issues with her bowel movements. Three months ago, she had roseola and experienced severe d...

Dr. Zhang Yingwen reply Pediatrics
1. The nutritional composition of lactose-free formula is similar to that of regular infant formula, so it can be continued even if the baby is nearly one year old. Babies over one year old can also obtain balanced nutrition from the addition of complementary foods. 2. Hydrolyzed...

Should You Switch Baby Formula? Understanding Digestive Issues in Infants

My daughter is currently eleven months old. She was originally breastfed, but recently we decided to wean her off breast milk and started transitioning to formula. However, after the switch, we noticed that her stools have become watery, although the frequency has not increased. ...

Dr. Xie Degui reply Pediatrics
Hello: Breast milk has a higher lactose content, so if breastfeeding is possible, there is generally no need to worry about lactose intolerance with regular formula milk. Watery stools may be a temporary phenomenon; if they persist, please bring a stool sample to the doctor for f...

Is Your Baby Experiencing Diarrhea After Formula? Possible Lactose Intolerance

My baby is currently seven months old and has been exclusively bottle-fed with breast milk. However, due to work commitments, we have started trying formula milk. Generally, after consuming Abbott Similac, a rash appears at the corners of the mouth within half an hour, so we swit...

Dr. Pei Rensheng reply Pediatrics
Hello: Breast milk also contains lactose, so your situation is likely not lactose intolerance. I suggest trying a different brand of formula. There is no need to specifically choose a lactose-free formula. Best regards, Rensheng.

Understanding Baby's Stool Changes After Switching Formula: Is It Normal?

The child is currently over 2 months old and has been assessed by a pediatrician as having an allergic constitution, leading to a change in formula from S-26 to Enfamil Hypoallergenic. Since switching to Enfamil Hypoallergenic, the frequency of bowel movements has increased and t...

Dr. Xiao Kaiwen reply Pediatrics
If the frequency of bowel movements has increased and the stool has a higher water content compared to when it was normal, this is defined as a mild case of diarrhea. It is recommended to temporarily switch back to the original formula. If the stool returns to normal, it may indi...