Should I change my baby's formula?

Most new parents who choose to bottle feed their babies begin with a standard lactose-containing infant formula.

All babies, to some degree or another, are spitty, gassy, and/or have "strange-looking" stools. This is true no matter what formula they get – in fact, breastfed babies have these "problems" too. Nonetheless, many parents ask, "Could it be the formula?" In most cases, no.

Doesn't formula make a difference in gassiness?

No. An excellent study published in the medical journal Pediatrics in 1995 (Hyams et al, vol 95, pp. 50-54) investigated this question. Volunteer parents were given one of 4 different formulas to feed their baby, but were not told which formula they had received. Parents were then asked to keep a record of their infant's stool pattern, spitting up, gassiness, and crying. Although the stool pattern was different (see below), spitting, gassiness, and crying were of equal severity in all formula groups. Unfortunately, infant formula manufacturers aren't always forthcoming with this information.

If not the formula, then why is my baby so gassy and fussy?

Most babies are gassy due to swallowed air, not the formula. Infants in the first few months of life can spend several hours a day crying. This forces air into their stomachs, which accumulates in the intestinesas gas. This crying behavior is seen in all infants to some degree between 6 weeks and 3 months of life. Gas gets better or goes away when babies start crying less as they get older.

Why does my baby spit up so much?

Most babies spit up regularly. Some babies dribble a little; others vomit whole feedings forcefully. Again, there is no correlation between the severity of the vomiting and the type of formula used. The "spitty" babies tend to be those who eat a large feeding (more than 3 ounces at a time) all at once, who take their feeding too quickly, who don't burp well, or who eat lying down. All of these things tend to overfill and bloat a baby's small stomach. This usually results in the baby vomiting. Read more about spitting up (reflux) to help with these problems.

Occasionally persistent, forceful vomiting in an infant can be the sign of a serious problem. Let us know if the baby vomits more than he is able to keep down, if you think he is not gaining weight, if he is getting dehydrated, or if he is acting very sick.

Does formula choice affect the baby's bowel movements?

Actually, it does. The Hyams study found that there is some correlation between diet and stool. Breast-fed babies and babies taking elemental formulas (like Nutramigen ®) tend to have the most watery stools. These babies also had the most stools. Babies fed soy-based formulas (like Isomil ®) have the firmest stools. Babies taking lactose-containing formulas tend to be somewhere in between.

However, babies are supposed to have this variation in stool. Fortunately, loose stools don't necessarily mean diarrhea; less frequent or firm stools don't necessarily mean an infant has constipation. So, babies rarely have true constipation or diarrhea because of the formula. Please don't switch just to "regulate" your baby's stools -- chances are they are supposed to look the way they do! If you aren't sure if your baby's stools are normal, ask us. (See our information about infant constipation and diarrhea.)

When should the formula be changed?

  • Lactose intolerance (very rare in babies)
  • Milk protein allergy.
  • Gluten enteropathy.
  • Metabolic conditions, like galactosemia.

These are all pretty rare conditions. Let us know if you are concerned about one of them.