L.H.
each change takes a good two weeks to see a difference.
is your baby a 'happy spitter?"
or full of pain & shrieking & howling that goes along w/ the spitting?
unfortunatley there's not much to do w/ a happy spitter...just a lot of laundry.
now, if baby is spitting & not gaining weight that's another issue also.
people will tell you to thicken the formula. I would not. there is no reason to and giving cereal early can add to chances of early diabetes, etc.
here's about thickening feeds: http://www.kellymom.com/babyconcerns/reflux.html
here's about starting solids: http://www.kellymom.com/nutrition/solids/index.html
you could also check out www.askdrsears.com
now, if baby has trouble gaining weight bcse he can't keep down formula, then I would ask for a SWALLOW STUDY. this looks at HOW baby swallows abd if baby is aspirating. After this study IF formula needs to be thickened, you will be told an EXACT consistancy (they use words like 'nectar' or 'honey') and you're given a thickening agent to use with the formuala (not cereal) to make it the right consistancy for your baby
if baby is in PAIN with all the spitting, I would get to a pediatric GI ASAP! I wouldn't mess around w/ a regualr pediatrician...
if baby seems to not tolerate a milk based formula, going for a soy one is not always the answer as about 40% of babies w/ problems w/ milk proteins also have problems with soy proteins.
so if you do try another formual try alimentum or nutrimegen, try the ready to feed kind (it's thicker) and give it two weeks before deciding it's not working.
good luck!