Yesterday I noticed that my year old hen has a prolapsed vent. A couple of hours later her rear looked fine but obviously there is a problem. I read to bathe her and put Preparation H on the vent and to give her some Karo/Olive oil and to to put her in a dark place to stop her from laying till it heals. I have her in a cage (with food and water) in the gargage with a flannel sheet over it. It's darkish but to get it pitch black I'd have to put her in the basement where it might be pretty humid. How dark is dark enough? And how long should I keep her there?