Milk and Constipation

Milk and Constipation
Milk and Constipation

Dr. Greene, our 19-month-old son has seemed to have trouble since his birth. He wouldn’t be miserable all the time, just a good portion of the time. At 1 year, he was introduced to cow’s milk. Before this time, he had consumed cheese and a few other dairy products. He is a very unsettled, miserable-acting child. As his mother, I know something is wrong. He has been having trouble with constipation for a while now. We have tried increasing fruit, veggies, and whole grains to no avail. He goes for days between stools, and when he does eliminate, there is a very hard, very large “plug” of stool that comes out, followed by two to five diapers full of loose stool within a couple of hours. His father is lactose intolerant yet can drink skim milk with no problems. My question is: should we try skim milk? Or should we try a lactose-free type of milk or soymilk? Any help would be appreciated greatly!!!
Shannon – Woodstock, Nebraska


Dr. Greene`s Answer:

A cranky, unhappy toddler may well be responding to physical discomfort. Tummy troubles of one type or another can make anyone feel miserable. Milk is a major part of most children’s diets. If a child is intolerant to milk, this can affect how he feels every single day of his life. Nausea, cramps, and pain can squelch the normal joys of discovery and mastery.

But the classic symptoms of milk intolerance are diarrhea, spitting up, or abdominal pain. Many kids with milk intolerance also wheeze, especially when they get a cold. They can also have the dry, sensitive skin of eczema and their noses always seem to be running. Ear infections are also more common than in other kids. Constipation, however, has not been typically associated with milk intolerance — until now.

The observation that constipation might sometimes be caused by milk intolerance has appeared in the medical literature from time to time, dating back as far as 1954 (Pediatric Clinics of North America, 1954; 4:940-962). But only recently has there been a well-designed study published showing that this is indeed the case. The results of this study, when widely known, can set many children free to enjoy the exuberance of childhood without pain.

Researchers at the University of Palermo in Italy worked with 65 children with chronic constipation. All of these children had been treated with laxatives when dietary measures had failed. Even with the medical treatment, these children were still constipated, having hard, painful stools only every 3 to 15 days. Forty-nine of the their little bottoms had fissures and redness or swelling from the hard plugs of stool.

Each child received either cow’s milk or soymilk for 2 weeks, with no one knowing which was which. Next, they had a week during which they could eat and drink anything they wanted to wash out the effects of the first 2 weeks. Then they switched sides for 2 weeks and got the milk that they didn’t get the first time. Careful recordings of the bowel habits were made.

When the secret code was broken at the end of the study, they found status quo constipation for each child while he or she was on cow’s milk. But while they were taking soymilk (which causes firmer stools in most kids), 68% of these kids were no longer constipated! The redness, swelling, and fissures on their bottoms healed (New England Journal of Medicine, 1998; 339:1100-1104). How wonderful to finally have relief after diet and medicines hadn’t worked for so long!

The results were most dramatic in kids who also had frequent runny noses, eczema, or wheezing. Nevertheless, sometimes constipation can be the only symptom of cow’s milk intolerance.

This has broad implications. The children in this study were those with severe chronic constipation that was unresponsive to medications. I am convinced that they are only the tip of the iceberg. There must be a much larger group of mildly allergic children whose constipation improves with laxatives. Time may prove that it is better for these children to avoid the offending protein by switching milks rather than being treated with laxatives.

Presumably, swelling of the intestinal lining causes the constipation. Whatever the exact mechanism, the problem is likely with the protein in cow’s milk, not with the fat or lactose (the sugar). Skim milk or lactose-free milk will not help with this one. Switching to soymilk and other soy products might transform the life of your son in only a couple of weeks!

Unfortunately, some children are also soy protein intolerant. As it happens, this is more common in kids who are allergic to cow’s milk protein. If you don’t get good results within 2 weeks, I suggest also eliminating soy from the diet for 2 weeks as a trial. You might use Alimentum or Nutramigen (protein hydrolysate infant formulas) as the milk for these next 2 weeks because your son is much less likely to be allergic to the protein in them. If they work, you can then experiment with other sources of calcium, protein, and fat for the future (perhaps rice milk).

It’s not that common for simple changes to relieve relentless, longstanding problems. But when a child is made miserable by an allergy, removing the source can result in a rapid, dramatic improvement in the quality of life. I hope, Shannon, that this turns out to be the case with your son and that this next season his smiles double to make up for those he has missed.

Reviewed by: Khanh-Van Le-Bucklin, Rebecca Hicks
Last reviewed: June 30, 2014
Dr. Alan Greene

Article written by

Dr. Greene is the founder of (cited by the AMA as “the pioneer physician Web site”), a practicing pediatrician, father of four, & author of Raising Baby Green & Feeding Baby Green. He appears frequently in the media including such venues as the The New York Times, the TODAY Show, Good Morning America, & the Dr. Oz Show.



  • Ang

    My little girl has had a constipation problem since birth but it is only when she drinks whole milk or 2% milk or anything to with milk period. I have took her to several doctors and done everything they have asked nothing has helped

    • Sara

      Ang, how old is your daughter? and what is she like with appetite?

  • Sinem Alanyurt Yalçın

    My daughter was hving chronşc constipationnfor the last one year. Even though the milg alergy test came out positive our dr told me i can fed her with any diary product. Now i changed our dr and we cut all mşlk productd as of today. For the last 2 weeks i ve been readin and readin annd this was the best article i have ever read. İ hope our const. Wil end very soon. Thx for all he information provided.

  • Savannah Kaye

    Well I had the same problem with it as well when u was a infant. Doctors told my mom I was iron deficit. Well that made it worse. So my mom started feeding me yogurt. And I have ate yogurt ever since and I know when I don’t get any yogurt in me because I become constipated. And I also only Finn 1% or 2% milk. I can not drink whole milk.

  • destiny

    My son has been like this as well, but only since switching for 1 yrs old. We switched to almond milk and did amazing!! But I grabbed Kroger lactose free and back to the same problem, horriblely. Poor gut! Not sure the difference between almond milk and Kroger lactose free milk.
    He has been though so much! Colonoscopy, 2 capfuls of Miralx a day, ex lax per doctor. Ughh. Definitely a different boy when using almond milk!

  • Danielle Patterson

    This article has made me so happy finally a dr saying the cows milk can cause constipation, previously my daughter had diarrhoea and odd sickness we ended up having to gradually wean her onto cows milk from formula which the full transition was completed in May when my daughter was 17month and then since 17 month on full cows milk it has been chronic constipation…the laxatives didn’t work she seemed worse if anything. I am now on day 3 of soya milk and I am really hopefully this is going to help her constipation! Will update the results!!!