Hi
Did you find outhas what it was???? I am really curious to know, because my 2 year old boy has the exact same "things" in his diaper. Sometimes these "hairs" are in it, and I thought he had simply swallowed some of my long hairs. But combined with the pictures you have posted, I am convinced that it is the same.
A couple of days ago I gave him a bath, and all of a sudden these "worms" were floading in the water. They looked exactly like the ones in your pictures. Sort of yellowish/light brown and some with a black "head". Sort of slimy.
So, did you find out what yours were???
PLEASE let me know!!