Re: DS has has diarrhea for >1 month...doc wants him on soy formula?
jUst a though. My 17 month old had this probelm for a month, with diarreah and vomiting for a motnh, we check for rotovirus, etc... thenit dawned on me we had started him on dairy, a motnh before that at 16 months but becaus ether ewas no reaction for over 4 weeks I didn't make the connection. Once we took him off dairy he was fine, within a few days.
Have you started any new foods in the last few months, that might be the offender and it just took this long to make him sick.
I might be tempted to go back to just breastfeeding for 1-2 weeks with no solids and see what happens.