Belfie, there is still a lot of research being done about this and there is no proven causal link. However, it is believed that allergies, excema, asthma, and a range of tummy and bowel problems such as IBS, Chrone's Disease etc, could be either as a result of, partly as a result of, or worsened by, the early introduction of solids.

As I say, this is not definite, but it seems to be a high risk to take when the one thing that is known is that solids are not usually needed before 6 months, and that no harm is done by not introducing solids even if the baby is ready.

I will have to find Barb's post. It's worth a read.