Consider the following scenario: one of my answers gets accepted, then somebody else edits what I wrote in a way that I disagree with. Now I have a post supposedly written by me, that doesn't reflect my views. Sure, the edit history is available, but how many people look at that? I might not be aware of the change myself if I happen to be away from the site for a while. And even if I am, I can no longer delete my post, since it has already been accepted. So, is there a reasonable way to deal with this situation? Can I somehow disown the post, so that it is no longer associated with my name? Continuously policing my posts doesn't seem to be a reasonable approach.
No, there is no easy way to disown a post short of requesting that your account is deleted. You can request that a particular post be disassociated from your account but that requires manual intervention from SE staff and should only be used in extreme cases.
In the situation you describe, all you need to do is roll back the edit. Go to the answer you are talking about, click on the review history and scroll down to the last version you find acceptable. There will be a "rollback" link:
Click on that and the question will revert to that version. As for continuously policing, that shouldn't be necessary. You are usually notified if time one of your posts is edited (there are some exceptions, I'm not sure about the details but an edit that is enough for you to object to should always come with a notification). If you don't like the edit, just roll it back.
Finally, please don't get into edit wars. If a user keeps editing their changes back, instead of starting an endless back and forth of edits, just flag the post for mod attention and we'll deal with it.