I have Buff Orpington Hens. Approx. 6 months old. They started laying about 2 weeks ago. They are on 100% layer ration with no other supplements. They are free range and have been exposed to the outside for 5 months. 2 weeks ago i had one get sick. She was fine in the morning, but by late afternoon she was slow moving, drooping her head, and would not eat or drink. She would bob her hind end like she had to poop or drop and egg, but nothing ever came out. She died that night. Yesterday i had another hen with the same symptoms but this one also pooped out a clear watery diarrhea, there was no blood in it, and she also dropped a broken egg with a really leathery shell. She also died that night. I talked to a vet and they thought it would be coccidiosis. All of the other chickens in the flock are looking good and well.