Help please - lethargic chook!

[GHJ1]

Hi, one of our Pekin Bantams appears to be sick. She is very lethargic, and not fussed by me picking her up (unusual for her). He bottom was covered in foul smelling green grainy poo. I've bought her inside and tried to feed her and give her water, she has taken some but not much. Her poo is not beige and runny with some darker bits in it. I've felt around her vent in case she is egg bound, but not sure what I'm feeling for, there appears to be a lump, but it's not hard. Any suggestions? I rang our local vet who told me that if a chicken appears sick it'll probably die within a couple of days. She's about 18 months old and has been off the lay for a few months (as far as I know - I haven't found any bantam eggs for a while). Our other chooks are fine.
Thanks!

 

[chickenzoo]

I would try to get her on an antibiotic and give her vitamins and supportive care. Has she ever been wormed?

 

[GHJ1]

Thanks for your help, unfortunately Cocoa died a couple of hours ago :-(