Illnesses > Illnesses in Infants > Constipation in Infants

Constipation in Infants

Click HERE to download this handout as a .PDF file.


Small infants can become constipated.  If your baby's stools are dry hard pellets, or if they're large, firm and painful, then he might be constipated.

Surprisingly, the frequency of the infant's bowel movements are not very important, as long as they are soft.  Some infants make a bowel movement only once every few days; if the baby is otherwise healthy, then this is probably normal.

A baby's stomach muscles are not very strong, so the baby may have to push in order to produce a stool. Often, parents will worry when the baby cries or seems to strain with a bowel movement; they may notice that the belly seems "hard." Again, if the stool is soft, then this is normal, and needs no treatment.

Constipation does not cause any symptoms other than the hard stools, some fussiness, and occasionally a mild increase in spitting up.  Persistent vomiting, fever, or congestion are not caused by constipation; if a fussy baby has these or other symptoms, an exam is needed; do not assume that the baby is simply constipated.

(Occasionally, a small amount of bright red blood can be seen on the outside of the stool.  This is common with constipation; usually, close inspection of the anus under a bright light will reveal a small fissure or abrasion.  This is not dangerous by itself, but it's a sign that the constipation needs treatment.)

On the other hand, true constipation in infants certainly needs to be treated.  Babies can (and do) learn that having a hard stool causes pain, and sometimes they try to avoid it, resulting in stool withholding behavior.  This behavior is difficult to treat, so it's best to treat the constipation as soon as it's noticed.

What causes constipation in an infant?  Usually, we never find out.  Occasionally a milk protein intolerance is the cause, and the problem might resolve by changing to soy or a different formula.  More commonly, especially with infants less than 2 months old, the baby needs to be fed more frequently, even as often as every 1½ to 2 hours or more.  But most of the time, the constipation appears to be a random occurrence.

Many folk remedies for constipation might be recommended to parents.  Unfortunately, most of them don't work.  For example, increasing the water intake does not help constipated infants; dehydration is rarely the cause of constipation, because breast milk and formula are about 85% water anyway.  Apple juice generally does not help.  Herbal remedies are generally of no value.  Massaging the abdomen might soothe the baby, but it does not help pass stool.

But in the short term, there are several treatments that do help constipated infants.  Rectal stimulation with the tip of a thermometer can stimulate a reflex that causes the baby to stool.  Prune juice or pear juice can help; they contain non-absorbable sugars that draw more water into the colon, which softens the stool.

An "infant size" glycerin suppository (from the drug store) can be helpful.  The waxy kind can be pushed into the rectum, up to your first knuckle; the body's heat will melt the suppository, which lubricates the stool and stimulates the colon reflex.  Or, you can obtain liquid "glycerin suppositories" in a small plastic tube; the tip is inserted in the rectum, and the bulb is squeezed to release the glycerin into the colon.  Either of these may be used, as often as every 20 minutes until the infant stools.  But if you get no result after the 3rd application, further suppositories probably won't help.  In unusual circumstances, an infant Fleets enema is can be used, but young infants rarely need an enema.

If the baby's constipation is persistent, it is easily treated.  I recommend Miralax® or a generic version, the same medication that an adult would use.  Once or twice a day, you can dissolve a teaspoon or two in an ounce or so of water or the baby's milk, and give it to the baby in a bottle, syringe or spoon.  Once you start the Miralax, it's best to continue it every day until the baby has gone 2-3 weeks without having any hard stools at all.  Stool softeners like Miralax are absolutely not habit-forming.  Some infants and children need daily Miralax for many months in order to prevent constipation; the Miralax has no side effects, and there is no reason to withhold or reduce it until the child can form soft, easily passed stools on his own.

Copyright © David M. Epstein MD, April 2010