I've done this and had a doctor that was kind enough to consider it. I had some mysterious symptoms and managed to find some things that I thought might fit it, and it helped him get a better idea of what I was dealing with.

He also went through and dismissed most of the more worrying possibilities, which set my mind at ease, and narrowed it down to a more likely condition.

So basically, I threw in a bunch of options and most of them were wrong. Thankfully I didn't walk in convinced that any one of them was absolutely the cause, but I imagine some patients do, and it can be a pain for the doctor.