Hen with a Poopy Bottom

Our Barred Rock hen has developed an issue of her fecal matter getting stuck to the feathers on her bottom. She is still able to pass her waste & lay eggs without issue, but her waste gets stuck to her bottom. We caught her tonight so I could get a better look at it, & the poop glob is about the size of a large baby carrot in all, & is clumped together up to her skin. I was going to attempt to cut it out, but could not get scissors between the glob & her skin. I didn't want to hurt her so I left it alone for now.

Our other 2 hens do not have this problem. She's a young hen, only about 8 months old. The hens eat regular layer feed. I do give them treats of the occasional suet block for birds & kitchen scraps.

Any suggestions on how to deal with this without causing her harm would be much appreciated! Also, is this just something that happens, or is it something that a change in her diet may help?