How Does Soy Formula Cause Constipation?

By Carly Seifert
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If your infant is stooling less than once a day, is excessively fussy, spitting up more than usual and has bloody or unusually hard stools, he may be suffering from constipation. While there are benefits and drawbacks to soy formula, constipation may indicate a soy allergy, and you may need to discuss more suitable formula alternatives with your pediatrician that do not cause your infant discomfort.

Potential Allergies

According to author and pediatrician Dr. Alan Greene, soy formula generally makes stools firmer, unless the child has an isolated allergy to milk protein, in which case constipation may dramatically clear up on soy formula. Allergies to soy formula may cause discomfort and be related to constipation, and it may be necessary to work with your pediatrician to find a formula with partially hydrolyzed proteins that are easier to digest and will not worsen your little one's constipation.

Benefits of Soy Formula

Soy formula may be necessary for your little one following a bout of diarrhea, which damages digestive enzymes in the lining of his intestines causing a temporary inability to digest lactose, according to the American Academy of Pediatrics. Some strict vegetarian parents may choose soy formula because it contains no cow's milk or other animal products, though the AAP recommends breastfeeding as the best option for vegetarian families. Infants suffering from a rare disorder called galactosemia, an intolerance to one of the sugars that make up lactose, must be fed a formula free of lactose.

Potential Drawbacks of Soy Formula

The AAP states that there are few circumstances in which soy formula should be chosen as a formula alternative in infants. As many as half of infants suffering from a cow's milk allergy will suffer from a soy allergy as well. According to the National Institute of Environmental Health Sciences, animal studies indicate that the health effects of consuming large amounts of soy include early onset of puberty in females and alterations in breast tissue development. Since their entire diet is comprised of soy, infants consuming soy formula have a much higher soy exposure level and may be more vulnerable to the estrogen-like effects of the phytoestrogens found in soy.

Treating and Preventing Constipation

According to the AAP, constipation in infants can be treated by giving small amounts of water or prune juice. If your child has begun eating solids, giving him fruits -- especially prunes and pears -- can also be effective. Prevent constipation by providing your child with plenty of water and high-fiber foods, and giving him opportunities to be active -- kicking his legs at the hanging objects in his infant gym, crawling around the room or cruising from table to chair.

About the Author

Carly Seifert has been a piano instructor since 2001. She has also covered adoption and introducing children to the arts for "Montana Parent Magazine." Seifert graduated from University of California, Irvine with a Bachelor of Arts in drama.