Danone, the French food company that makes Aptamil, has changed three of its formulas recently. Parents are posting online that they blame the formula changes for their babies' illnesses, with symptoms including vomiting and diarrhea.
"She has been sick after every feed since starting this new formula," said Rachel Davies, 25, a mother in Wales whose baby, Melissa, is 3 months old.
Parents have flooded the Aptaclub UK Facebook page
-- a customer service page for Aptamil products -- condemning the company's new baby formulas.
In response, Aptaclub UK said it has been listening to feedback from parents and is willing to investigate issues that arise with its products.
"We take every concern very seriously and rest assured any issues with our products are investigated thoroughly," Aptaclub UK said in a Facebook post
Friday. The post added that the new formulas had undergone "exhaustive checks to ensure the quality and safety is of the highest integrity," with results showing the products "were well tolerated by babies and safe to consume."
Danone UK has not responded to requests from CNN for comment.
Online, parents have posted that their children's symptoms stopped when they switched to a different company's formula or old versions of Aptamil formula.
"I managed to find the old Aptamil and (Melissa) was great again, no problems," Davies said.
But after running out of the old formula, Davies said she again used the new one and shortly thereafter, Melissa fell ill again.
"At 3 a.m. this morning, I drove to my local superstore to get a different brand of milk. She hasn't been so bad after that," Davies said.
Online complaints note that the new milk powder doesn't dissolve, leaving large clumps in the liquid.
"We have changed our mixing instructions slightly and, with hindsight, we could have made that clearer," a post on the Aptaclub website
In the former stage 1 formula, it recommends users to "shake well," while in the amended formula it recommends that users "shake vigorously."
In a Facebook post
, the company said the new products are "more sensitive to temperature than in the past," and users must follow mixing guidelines to boil water and "cool in the kettle for 30 minutes and no longer," and that it is "important to shake the formula milk vigorously and vertically for at least 10 seconds."
Aptaclub UK shared a helpline number
parents can call for assistance. When Davies called the number regarding the new Aptamil formula, she said the representative she spoke with "blamed" her for not following instructions properly.
Davies said she asked the Aptaclub representative whether the company intends to take the formula off the shelves until the problem had been investigated. The representative told her there are no plans to do so, Davies said.
Danone has amended three of Aptamil's baby formulas -- Aptamil First Infant Milk powder (stage 1: from birth), Aptamil Follow On Milk powder (stage 2: from 6-12 months), and Aptamil Growing Up Milk powders (stages 3 & 4: From one to three years).