I have a 10 month old and we have been struggling with starting solids since 6 months old. This week we finally saw a pediatric gastroenterologist and he believes that DS has a minor sensitivity to a protein in my breastmilk, and that is what is irritating his stomach and also causing the constipation. DS is growing well. He has said to continue nursing ( I would have done this anyway) and continue solids, but I am still confused by this and wondering if anyone has heard of this, and what I can do to help it. MD recommended apple juice, few oz. a day, but I'm not sure I want to get DS started on apple juice as he only now has water and breastmilk. I'm just confused and wondering if anyone else has heard of this. I haven't been able to find anything out there on this condition.