got these two barred rock hens and their tail feathers have been plucked and it looks like their buttholes are scabbed over and bleeding, any ideas on what the cause is or how to help them?
Assuming they were previously kept with other chickens, it could be a result of an overly aggressive rooster or being low in the pecking order. Otherwise, it would be a good idea anyways to check them over for mites or anything else that could be causing them discomfort.
If their vents are scabbed up badly, it could help to rub on some vaseline or antibiotic cream to prevent them from getting pasty butt and act as a buffer for their sore skin. So long as they aren't picking on each other, it takes time to grow back feathers. You may want to look into getting hen aprons to help prevent them from being able to pick at each others backs while they heal.