Quoting Brandi Lynn White:" Yep he gets that for breakfast and he still spits it up 2 tablespoons of oatmeal mixed with formula. Nothing stays all the way down. "
My guess is acid reflux. Try smaller feedings more frequently. Say he eats every 2-3 hours, feed him smaller portions every 1 1/2 hours...cut them in half and see if that helps any. Poor guy, I'd refuse to leave the pediatricians office if my baby done that after so long (roughly it takes 2 weeks for adjustments)