On of our Auracana's had a prolapsed vent a while back, and after cleaning/prep-h/shoving it back in 3 times it stuck and she was good. We have a polish whose vent is prolapsed as well, but we can't seem to resolve it. We've cleaned her up 5-6 times now, and kept her isolated for a week in a dark box, as I believe this we recommended. This morning, we clean her up and the moment she poos it's popped out again. Suggestions?