Bloody vent, diarrhea(?), otherwise fine.

[Capucine]

I bought 3 one-year-old Barbu D'Uccle Bantam hens a few days ago. They've been getting settled into their new coop and have been giving me an egg a day. One hen, the fattest, has been laying eggs with blood smeared on the shell. She also is the most agitated when she's about to lay an egg. I checked her out today and her rump is 1.) bald but with some feather regrowth 2.) feathers seem a bit soiled and 3.) her vent had some mucousy blood hanging from it. She looks red and swollen compared to the Queen Bee but doesn't seem prolapsed. I rinsed her off in warm water but I can't really get a good look at what is going on down there. She almost looks torn since the blood is mostly on one side (I'll try and take a pic). Her eggs are bigger compared to the other hens. I put her in isolation for right now until I found out what is going on.

Here is what I know about them...They had been paired up with a rooster and 2 of them have obviously been pecked. When I got them, there was some bullying going on and my sick one was #2 out of 3 in the pecking order. Since I put them in a run and gave them plenty of space, I haven't noticed any pecking. I also haven't seen any diarrhea. Mostly just fluffy chicken poop.

Other than the blood and poo dribbling from her vent. She's eating, drinking, scratching, and making normal chicken noises. Could it be stress from the recent owner change? Stress from the recent pecking? Eggs to big and causing a tear?

I tried searching for this but wasn't finding exactly what I was looking for. Any ideas??