Bald chick butt. Need help

[Robblob]

So I was checking on my chicks this evening and noticed one of the chicks has a raw exposed butt. I've provided a detailed picture (you're welcome) to help give me an idea of what's going on. Anyone know?

 

[Jensownzoo]

Mine have looked like that after a chunk of dried/stuck on poo was removed (along with the underlying down). I spritzed it with Vetericyn. The down eventually grew back.

 

[logybe]

I had same problem. Thanks for advice.

Logybe