Do you have your bill where it shows if they did a fecal float?
If it doesn't say, then call and ask.
There's blood in the poop. It's mucousy.
If she were mine, I would treat for worms and Coccidiosis. Maybe an antibiotic as well for infection. I'm not a vet though...
EYP is never cured...
You don't mention if she's currently laying eggs.
Can you get some photos of the sour poop that is like jelly? Did the vet run a fecal float on a poop sample to see if worms might be part of the problem?
What do you feed, including treats?
The neck twisting is a neurological symptom...