Vent away, hon! It helps!! I know, I do it all the time here. LoL! I'm sure people are tired of me rambling on and on.
I live with a bp husband. But, I must say this...your wife sounds more like I do. I do the exact same thing with my husband. I go into this shell and don't let him in. Then in return, he does the same thing to me. So we are just darned no matter what we do. ;-)
For me; I get this rage of anger in myself that I just can't control. So therefor, I ignore my husband when I'm like this because I do NOT want to fight with him...especially with him having bp. Sometimes, I dont even have a right to be mad at him, he hasn't even done anything at that point to me. I think for me though, it's more all the past things he has done. In his manic states, he leaves....and this has deeply hurt me. So maybe, Im just putting my guard up, I dont know. I'm not saying this is what your wife is going through, because I have no clue. Im just letting you know this is what I do.
Here is an example of how ridiculous I am: We are living with friends (as I've told everyone 100 times already, LoL, Sorry) anyhow, they moved their niece in. She is like 32 or something. Well, I don't trust her...not so much that I don't trust my husband, its more her. Well, if he is upstairs watching TV with them, or whatever, I get sooo mad!!!!!!! I mean, MAD! I won't talk to him at all and the poor guy has no clue what he's done. I try so hard to control this, but I can't. I just get this fit of rage in me that wont go away and I don't know why. Its absolutely ridiculous what I do. BUT, I can't control it. It sucks! Actually, if anyone has any advice for me on this one, please, please, Ill take anything. It's actually ruining my life right now. I dont sleep at night because I'm so afriad he is going to go upstairs and she'll be up or something. It's horrible! Last night he went up to give our friend some shirts someone had given us and he was up there for more than 5 minutes and I freaked out. How insane is that?
Anyhow, I don't know if this helped you or not, or even if this is anything like your wife. I'm just sharing what I do. Insane, I know, but it's my life right now.
Take care, keep your chin up, smile and things will work out.
And vent anytime you like. I love reading others stories, so please, keep them coming. ;-)