What is this??

[waddles99]

Today, when I inspected my buff Orpington hen, I noticed she had a large round bloody ball coming from her vent. I touched it and it was soft, and pus came out. She is acting fine, but I am still worried. Anyone have any thoughts??

 

[Eggcessive]

She may have a prolapsed vent, or some sort of abscess from pecking, or both. Can you post a picture or two? Here is some reading about prolapses:
http://www.the-chicken-chick.com/2012/04/prolapse-vent-causes-treatment-graphic.html
https://www.beautyofbirds.com/Prolapse.htm