What is wrong with my chicken??

[tastylancs]

This is my lovely wellsomer Coco. I noticed last night that she's bright yellow on her backside. She's out and about and eating and drinking but this doesn't look good does it. Worried. Anyone any advice as to what's going on?

[Todamhottoday]

Looks like excess poo, has this been building up?

Can you get a hold of her and have a good luck, this sometimes happens and you need to wash it all off

[Todamhottoday]

..good look