Question for Moms using Soy Formula

laurenac

My LO is almost a month old and we have been having the worst issues with formula!  The plan was to breast feed, but for a number of reasons my supply is low, so we have been supplementing with formula.  We started with Similac Advance, but he was having very mucusy diapers and a lot of them.  The doctor suggested we try Gerber Soy - but now he only has one BM a day - and he cries for an hour before he goes.  When he finally goes, it is more of a paste like substance and it just seems so hard for him.  Is this normal for Soy formula?  I did read online how it can cause constipation.  Just wondering what your experience in using soy formula has been like...

I was mixing 1 oz of breast milk in with the 2 oz of Soy, but my doctor also asked me to stop for a week to see if that makes any difference (he thinks he might have a milk allergy and also would be sensitive to the milk proteins found in my breast milk) - I am tempted to add the breast milk back to see if it helps with his digestion at all. 

Thanks