Re: what is considered a greasy stool in an infant
We were always told shiny, sometimes a greasy residue in the diaper. With DS his were never really greasy looking -- just very soft, very frequent. His tended to be fluffy -- almost like the consistency of fluffy whipped frosting.
As he's gotten older we've actually seen oil blobs or residue in the toilet. Suppose you could try dropping the contents from the diaper in the toilet to see.