A: I have never heard of babies vomiting more on powdered formula than concentrate or ready to feed, and I have been a pediatric nutritionist for 25 years! Is your son actually vomiting or just spitting up? If the episodes are forceful and the vomit travels some distance, you should be speaking with the physician, not his assistant.

If the baby is just spitting up, he may be drinking too fast, drinking more than his stomach can hold or taking in air, which can cause him to bring up some of the formula when he burps. Also, please be certain that you are measuring the powder and water exactly as the directions state, as excessive powder to water can cause serious problems.

If none of the above is the problem, try a different brand of formula. Although most milk-based formulas are very similar, there may be subtle differences among them. Your baby could be sensitive to one brand but tolerate another.

If the problem does not resolve, please call your pediatrician and ask him or her to examine your son to rule out any allergies or medical conditions.