thanks everyone for your feedback. I think I will be putting it down on my birth plan that they're only to occur if absolutely necessary. And I'm sure my private midwife will make sure that's the way it will happen.

I'm sorry to hear people have had such bad experiences with them - I just wasn't quite sure how it all works, I mean I know the opening of the cervix stretches but I wasn't quite sure just how the opening to the vagina stretches. Very interesting stuff, but I hope I dont absolutely need an internal.

Thanks everyone!!