Our hen Bonnie, a former shelter hen, has a big butt.
And because of that, Bonnie is due for another bath soon. She is truly the largest hen I've ever seen. And for some reason, she always gets poop stuck below her rear end. I don't know if the poop problem is because of her weight issue or what. None of our other hens are fat. It's hard to put one out of 17 on a diet. I think Bonnie is actually healthy, and she appears to be a happy hen. She just has a big butt, along with a big everything else.
She doesn't have diarrhea, her droppings are not running, she is not sick at all. None of the birds are sick. Bonnie is energetic and happy and healthy.
The poop gets stuck on her feathers below her butt/vent. I think it's because her butt is so very large and round and fluffy. I tried cutting the feathers around and below her vent so they just weren't so darn fluffy, but I didn't do a good job. It was more of a choppy cut. I did it right after her last bath, when the feathers were wet. When the feathers dried I realized what a bad "haircut" I gave her. And right after the chop job I noticed she got poop stuck in the fluffy feathers below her butt again.
Luckily, Bonnie loves baths, as do all my chickens. I think I'm destined to give her baths every few months.
I love my hen with the big butt! Baby got back!