We adopted this 3 year old hen from a flock of about 40 girls in a nice backyard coop. It wasn’t a large space but seemed clean and secure. When we got her to her new home, we noticed her back side was discolored with poop. After further investigation, she had this massive dark hard ball of what we thought was dried poop, But it was all around her vent and was almost closing it up. We cut it off and cleaned her vent but we cant get the scab to fall off. It seems to grow with the yellow discharge that adheres to the scab and gets bigger. She wasn’t laying eggs at first, but now she is and they are discolored with the discharge. She eats well, has fresh water, good food and lots of free range space. We take her in daily and soak her in epsom salt and try to clean the discharge and cut back the growth. But if we cut too far it bleeds. We treat it with wound care and iodine. Anyone have any idea what this is and how we can fix it?