I frequently encounter situations where someone has edited my question/answer. How do I know what has been edited?
If you click on the link that says something like:
edited 21 minutes ago
Then this will take you to a page that will show you what the edits on your question or answer are.
I should also point out that having your question edited is not an indication of a poor question - it is part of the culture of stackexchange to allow people to edit questions and answers to produce higher quality resources for other people to use.