Bantam chick clogged vent?

[Chickie Chicks]

Hi all,

This is a bantam about 3.5 weeks old. A couple days ago I noticed this thing on its butt. I’ve been doing warm epsom salt soaks and applying a hemmeroid cream. I just separated it and gave it some food with egg and put sugar in the water. Does anyone know what this is and what I should do?

It has 6 much bigger sisters in the coop. This is the only bantam.

 

[Chickie Chicks]

Here is a better photo

 

[Chickie Chicks]

And it is pooping