Cathy has Diarrhea and is Lethargic, but IS Eating

Hi all,
I was hoping you could give me some advice. I have a, what I think is a Jersey Giant, maybe a Black Maran? Her name is Cathy, she is the one in the middle, her sister is Patty, the one in the forefront. I got her last September as an adult. She is very lethargic and sleeping a lot. She has diarrhea. However, she is drinking fluids and she is eating. I gave her some yogurt tonight and she is eating that as well. I checked for binding, but did not feel any eggs lodged.

The chicken feces is pure liquid with a tinge of honeycomb yellow. She is now Quarantined, any ideas?