It's difficult to know exactly what is going on with more details. But from the sound of it when she gets turned on she gets extremely sensitive and tender, and continuing to do anything with her triggers her pain receptors.

Your doctor can provide pain medications for this to numb her nerve endings.

As for having an orgasm, it isn't something that just 'happens'... She has to learn how to trigger her body to release once she is aroused. No matter how good you are, no matter what you do... It won't do much. She holds the key to unlocking her orgasms.

You know I saw in a movie once (don't remember which one and don't know if this is even true) but anyway, this guy was trying to give his wife an orgasm. That is what the movie was about. Strange. But, she felt pain also when she got close. For her it was psychological, but he also needed to learn to be more tender, patient, new skills etc.
But again, it was a movie so who knows.
Anywho, keep in mind that the clitorus is very, very sensitive. You cannot apply very much pressure to it or it does hurt. It may not hurt right away, but within a minute or two it will. Be very gentle and when you get a good response keep doing what you are doing. (lots of guys when you let them know they are doing well will start doing something else and it is so frustrating that it is impossible to orgasm after all of that)
if she still cannot climax after all of your and her attempts then maybe she should see a doc. It could be a disorder, or it could by psychological also.
Either way, try to convince her to seek help with it because she will enjoy sex a whole lot more if she learns to orgasm!

I just joined this ehealth thing so your questions may already been answered but for what's it's worth. I was married almost a year ago and I expereinced pain when we had intercourse. So bad sometimes that I thought I would vomit. Pain with sex is a symptom of indometriosis. She ought to get this checked out if it has not gone away. Other sighns are painful and very heavy periods. Turns out I had all the sighns but not indo. My uteres is "upside down" if you will, don't know how else to describe it. As a result this caused pain and I also have ibs and turns out it too can cause pain with sex. I had stopped taking my meds when we got married so when I got back on them, the pain went away. Hope this helps - in conclusion she really needs to go see her obgyn.

I was under the impressin that the first post was speaking of such things as clitoral stimulation? That is what I responded to, but if I was incorrect please let me know.
Yes, if she is having pain with actual intercourse that is quite different and should definately see her doctor. If she is having pain with stimulation then I stick with my above post.
Yes, endometriosis causes many problems and quite a lot of pain for some women and can be a very serious problem. But, it wouldn't affect clitoral stimulation, only penetration and such.

If your wife is experiencing pain from manual stimulation - perhaps the problem could be lubrication based.

Try adding heaps of oil or other such lubes, and not focussing quite so much on her clit..

Alternatively - if she is still supersensative and feeling pain, try bringing her to a waterbased orgasm.. By directing a focused stream of water, similar to that experienced in a spa or pool spa, or hand held shower attachment - at "the " spot .. & letting the water do the work.

Once she pushes past the pain barrier, or the overstimulation barrier, and recognizes the steps to orgasm it might be an easier thing to do as a couple.

Hope this helps.