Prolapsed vent??

[bbecca]

Could maybe someone help me? I came home to find my hen with what I believed was an impacted egg or prolapsed vent but an egg was hanging on the outside in the mess of it all too. Her feathers were all fluffed and wet, full of poop and white stuff and blood and she smells horrible. Before I could look online to see what to do, my husband took the egg out of the mess and she was dripping blood for a while. It finally stopped and I took her in to clean her up, but I cannot even find the vent to try to put it back in. It basically looks like her insides have all come out in the back and are just hanging. Id like some input on what the problem is, first time around with chickens. Called vet and they said from my description there's nothing they can do, so I don't think she'll last. But I'd like to know what is the problem. Also if this helps, 3 out of my 6 hens started laying just 2 weeks ago but I'm not if she's one of them or not.