HELP!!!

[Falsa]

one of my hens (almost 4 years old) has been sick for a few weeks now. at first she didn't move much or eat, now she is turning yellow/white. her poop is also running down her vent. i have no idea what she has, any advice on what to do.

 

[Chicharron]

I once had a girl just like this, with the poop running down her backside, and not eating much. Just kind of laying around. Her feathers got really dull too. Maybe vent gleet? Mine seemingly got better but then one morning I found her dead in the coop. Hope you figure it out.