I have been behind on my post but wanted to add to this case.
In the original post, the baby was described as noisy when nursing. Was this
nasal sounds or gasping sounds?  When did the spitting up start?  It appeared
in the post that the spitting was progressively worsening and the baby was
upset afterwards.  The weight gains were good and you said the stool numbers
were normal but what did the stools look like?
If the problem is over production or a forceful EMR there are some key things
to look for: the moms tend to get very full or engorged early in the
postpartum period and continue for a few months when getting close to feeding
times; if the baby is in a position where their head is higher than their
hips, the large vol. of milk comes too quickly for the baby to handle,
therefore they cough, sputter, gag or come off to regroup for the
suck/swallow/breath sequence; the stools tend to be light green and sometimes
foamy; the babies have more gas and explosive stools; and when the mom pumps
she obtains large amounts of milk quickly.
I agree with Pat that there are 2 types of Reflux: the laundry problem, and
the medical problem where the baby demonstrates distress during or after
spitting up.
I also agree with Barbara that this may be an allergy problem.  So if this
mother started introducing her pumped milk back with the Soy that the
symptoms may reoccur.
If the problem is Reflux due to mother's over production see if the baby and
mother fit the description I gave above.  The Avent bottle may be pacing the
feeding so the baby can handle it therefore keeping it down and less distress
on the baby's part.
Let us know how this baby does.
Ann Perry RN IBCLC
Boston, Mass

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