[Tuor in Gondolin]

Originally Posted by LotR; Lothlórien
On the land of Lórien there was no stain.

So unless those flets were hooked up to some good plumbing, the answer is no: much like ladies, Elves produce no excrement.

Well, where do you think the fertilizer to make Lorien so
fertile came from? I don't recall Lorien had large quantities
of animals of any kind.

But seriously (sort of) "dim" views of excrement, like sex, seem
more of a limited medievalish worldview then anything else. Why
would enlightened elves see them as more then a natural aspect of
Iluvitar's creation?