This could be due to some sort of damage in the chickens oviduct, or maybe in the bowels there could be some sort of cut or stretch that could have made a small rip or tear, maybe from an abnormally large egg?
Recently I got my son a bb gun for his birthday, and he shot one of our chickens in the eye. He immediately told me and then i removed the bb from the chickens eye. The chicken is now acting lethargic and its eye is closed. Any way i could help this chicken recover?