Bloody egg/ poop lethargic hen

[Annabellaa]

I found this bloody/ eggy poop in my coop last night. For the most part my hens are ok. Struggling a bit with boredom and cold but nothing crazy out of the ordinary. I have one hen that is noticeably puffed up and her abdomen is swollen. I did a fecal float which was negative, she’s been laying eggs and her poops haven’t been yellow so no egg binding. She had a lot of poop on her bum feathers and seems to be straining to poop. I don’t know if this is from her (I haven’t seen blood in any of her poops) or one of my other hens. But it definitely looks concerning to me but I was wondering if anyone else knows what would cause this before I panic.