My serama hen looks like has a swollen egg shaped area on the side of her vent. After examining it’s very soft not hard like an egg and vent is on the side of it. I don’t know what it is or what to do.
It is probably a prolapse of one side of her vent.
I recently had a few week old chick with a vent prolapse I treated for a week and it did get better. I washed the area twice per day with soap and water and blew dried her on low with a blow drier, then put the equivalent ointment that Preparation H is on it.
Since yours is an adult, you probably could forgo the blow drying.
I also gave her vitamin water, either Poultry Cell or Nutra-Drench, whichever bottle was handy at the moment.