Swollen booty below cloaca

Just gave my chickens their butt baths and found Lemon has a very swollen and red behind but below the cloaca. She had a lot of poop buildup but she also just has long butt feathers. Its not bald (just looks that way cause the feathers are wet) but red, protruding and squishy. She seems otherwise healthy: eating and drinking. Not sure if she's laying. Last picture is post bath.

Is this just a normal juicy booty? Any idea what it could be if not?