It's difficult and unpleasant to acknowledge what happened. By doing so they would have to acknowledge and deal with what happened in the past (that caused DID in the first place). Part of therapy is to take them on this road. They're able to cope with reality because they're able to compartmentalize their history. Hearing about it, while necessary, weakens the coping mechanism that helped them survive. So you can imagine why they wouldn't want to hear about it.

And on a far more simple level, disassociating and returning from it is utterly terrifying, and worse still one might know that their loved ones will have also had a very difficult experience

I've seen that "exposure" therapy is often used in the treatment of OCD, another form of anxiety disorder. Patients with OCD often have an anxiety about something and use their quirks and rituals to avoid/ignore the anxiety. To help them cure their rituals, they must actively try to experience the often very extreme anxiety that some situation puts them in. Is the treatment similar in cases of DID?

No, that would be too much for a DID patient and could lead to further splitting (creation of new parts). First step is to teach them to stay grounded, to stay present and not take the easy path and dissociate (i.e. go away). When struggling to stay present someone with DID may exhibit OCD patterns -- scratching, grabbing, fiddling with fingers etc. -- all without realizing. However, when this happens there's usually some level of co-consciousness with a part that is suffering or has OCD. So in this case the OCD behavior would "belong" to that part while some other part is "out" (they'd actually both be "out" at the same time). It's a very complex disorder.

Hmmm, interesting. Thanks for the response.

I dealt with physical illness which caused large amounts of anxiety and stress. If you've recovered from a dehumanizing situation, often you don't want to invite those negative emotions back into your life. You just cross your fingers and hope it doesn't happen again.

>while it would be incredibly difficult to go through this, it would be harder if she woke up the next morning and didn't want to acknowledge or know about what had happened the night before

It's not that bad. Once you go through the exercise a few times, you have strategies that work, and it's about on par with having a sick child, where you might be slightly frustrated that you have to take a day off of work or make other arrangements, but you know the steps to take and get on with the day.