What is this? egg? poop? puss?

[Samblast]

this was found in the nesting box yesterday. It is yellow now due to sunlight. It was white with consistency of a large solid poop. Now hard with moisture inside. Found in coop with 2 barred rocks and 1 ISA brown. 2 barred rocks both laid normal eggs today. ISA brown is still molting but almost done. No eggs from her yet but some squats.

Could it be a lash egg? If it is what should I do? Thanks

 

[Samblast]

Inside

 

[aart]

Could it be a lash egg?

Yes.
Indicates a reproductive system infection.
Sometimes antibiotics can help.