I have one like that, she scared the crap out of me the first couple of days with it. She is my best layer, happy, active, smart and the alpha hen.
So it appears that she is "miss piggy" being alpha, she tends to get as much feed as she wants. But after removing all feed after they went into the
coop for the night, I got up early and got her before I put the food back in and low and behold she was nice and flat. No poop problems or anything.
She is a short, stocky girl which also makes it seem more pronounced. I have been keeping an eye on her and it seems that in late afternoon, early evening
she pigs out. Been making sure she has plenty of grit on the off chance, but all seems well and it's been weeks now. I've tried to curtail the heavy one time eating and
strech it out in smaller bits over the day....either way she's fine.