Possible cow milk allergy? baby has excess phlegm after eating?

Ever since my baby started formula she gets a lot of mucous during and after eating. She coughs and sounds raspy and then after an hour it goes away. She was recently on a steriod (for Infantile Spasms treatment) and during that time she had no mucous (steroids reduce this) but now she is off the steriods and the mucous during eating is back. She has no signs of a cold so I want to think it is the formula. I called my pediatrician and the nurse said to try her on another formula but didn't specify what.... She is now on Targets version of Enfamil. Anyone have this problem?