Tegretol is one of a variety of medications in potential use when lithium (which is the only medication specifically developed as a mood stabilizer) no longer is effective. This is some information on mood stabilizers in general including Tegretol:
http://www.psycheducation.org/depression/meds/moodstabilizers.htm
For some people it has an easier to tolerate side effect profile than lithium. I found the side effect profile of Lamictal to be better as well as the efficacy but each person responds differently to each medication. One thing that should be noted is that the medication Trileptal is basically clinically the same as Tegretol but because of some specific variations it has a safer side effect profile and does not require regular blood tests so if your psychiatrist decides to use Tegretol it would be worthwhile to ask about that.
What you should do is review Scientific American, which suggests that bi-polar disorder is the result of a specific infectious agent, and is in actuality an auto-immune disorder, rather than something caused by poor toilet training.
And the good news is they have identified an organism.
And there are clinical trials overseas on a drug that will counteract the affects.