That was my post, but I did not say that eggs come out with stool on them. I said that they are inevitably coated with faecal bacteria. The shared opening at the back end of the hen is not sterile; it has a normal microbial flora that largely comprises bacteria from the digestive tract (aka faecal bacteria). The egg cannot exit the hen without running the gauntlet of this final portion of the digestive tract.
But don't take my word for it: look at the eggs your hens are laying. Some eggs have a swipe of either poop or the white material that passes for urine in birds, even though there is no chicken manure at all in the nesting box. That material came from the cloaca as the egg was being laid. Also look at the back end of your chickens: they don't always do a good job of wiping their butts.
Sorry to burst any bubbles, but the surface of an egg is not as clean as it might appear.
Even so, that doesn't mean unwashed eggs are unsafe for most people. Households with very young children, elderly people, or immunocompromised people should take extra precautions with eggs, but most of us rub along just fine with eggs straight from the hen's backside. I give my hens' eggs a wipe with a dry paper towel before putting them unwashed in the fridge. I wash only those eggs that have some poop or urate deposits on them, and clean them only as much as needed to remove the surface debris.
Hope that clears up any confusion.
-Chris King-
(veterinarian)
