Mystery illness?? Crop Problems?

[treecow]

I have a three year old Buff hen who has lost a lot of weight and stopped eating and drinking as much as she used to. Three days ago she started barfing a clear liquid and it sounded as if she was gargling. When the vet emptied her crop to see if there was anything stuck, nothing but liquid came out and it didn't smell sour. She was also moving her head around like something was stuck or like she was trying to vomit. Maybe she has a,crop problem. I was also wondering what an empty crop should feel like in the morning. Hers is smaller than usual but is not like an empty water balloon. If anyone has any idea of what this could be that would be extremely helpful.

 

[treecow]

Also, what exactly should an empty crop feel like in the morning. Like an empty water balloon where both sides can touch each other or like a muscular golf ball? Not sure