A study published in May 2010 indicates that a diet without cow’s milk proteins can help to alleviate constipation in children. Researchers at the Hospital de Cruces, Spain enlisted 69 children with chronic constipation for the study. All of the children followed a cow’s milk-free diet (rice milk was used as the alternative), and 51% (35 of the children) improved. A cow’s milk challenge was then introduced and 8 of these children did not develop constipation, but the remaining 27 (39% of the total study group) did. As to be expected, these 27 children were relieved of their constipation when the cow’s milk-free diet was introduced for a second time.

But wait, there’s more … a whopping 78% of the children in the study with developmental delay responded to the cow’s milk-free diet. 

And this isn’t the first study to yield such results.  In 1998, Italian researchers conducted a similar observational study with 65 children with chronic constipation (they used soymilk as the alternative). 44 of the children (68%) had a positive response while receiving soymilk, with symptoms returning during the cow’s milk challenge ...

Interestingly enough, the researchers in Spain found no significant statistical difference between the children in their study group who saw improvement from the cow’s milk-free diet and those who didn’t in terms of “fiber and milk consumption; atopic or allergic history; full-blood eosinophil count and percentage, and lymphocyte populations; immunoglobulins, immunoglobulin (Ig)G subclasses, total IgE; and serum-specific immunoglobulin E for cow’s milk proteins.” In other words, the constipation didn’t appear to be related to an immune response (allergy) to cow’s milk proteins.

However, the Italian researchers saw a higher frequency of coexistent rhinitis, dermatitis, or bronchospasm , and signs of hypersensitivity, such as specific IgE antibodies to cow's-milk antigen in those children who did respond to a cow’s milk-free diet - indicating a potential mild milk allergy or intolerance connection to the constipation.

Though the jury is still out on how exactly constipation and milk intake could be linked, the results of these studies could offer the potential resolution of chronic constipation for many children.

Could a milk-free diet offer such relief to adults too? One would assume so, though all of the studies we found pertained to children. 

 Sources:

• "Cow's-Milk-free Diet as a Therapeutic Option in Childhood Chronic Constipation," Journal of Pediatric Gastroenterology and Nutrition, 4 May 2010
• "Intolerance of cow's milk and chronic constipation in children," N Engl J Med. 1998 Oct 15

Article by Alisa Fleming, author of Go Dairy Free: The Guide and Cookbook for Milk Allergies, Lactose Intolerance, and Casein-Free Living.