Do I need to remove chick?

[winonajane]

I just bought 4 chicks today, 2- 2 week old white leghorns and a amerucana and a buff orfington. They are both just a couple of days old. One of the older chicks has a runny butt. Is it catching? Should I remove her from the others? Can anthing help it?

Please see here
https://www.backyardchickens.com/forum/viewtopic.php?id=332204