I'm glad to hear that you've found a different doc to do your surgery. I believe that "the wrap has herniated" means that the hernia repair (which is what holds the wrap in place) has broken down, allowing the wrap to migrate, thus stopping it from working properly. I was told that a failed hernia repair is the main reason for a failed wrap.
How has it happened? Your guess is as good as mine. My guess would be that it wasn't done properly in the first place, but who knows? Did you have a vomiting illness during the recovery? That would be an event that could destroy a wrap.
At any rate, whatever caused it, the main thing is that you're going to get it fixed, and hopefully very soon! I'm sure it's hard to live with those nasty symptoms again!
Very best wishes!