I just bought some chicks at TSC yesterday. Most are fine, one has a weird thing on its butt. Can't tell if its a really bad case of pasty butt or exposed yolk sac. Anyways, please help as I'm nervous for the little fellow. Here is a photo https://ibb.co/iTiWN7 His butt is wet cause I tried to wipe it and soak it in warm water. When I wiped it poop kept coming out like he was backed up. I put him in a separate box. Is that necessary?