I would just keep an eye on it since it resolved on its own. If you do wind up having a prolapse here is a thread that is short and sweet to read and will give you a plan of action if you have to deal with it!
As a second thought. If you are rather new to chickens, this is an excellent article to read and save. It helped me a lot! I went and bought a lot of these items before and emergency happened! Some people medicines you may have on hand can be used on chickens as well. Always do a search on BYC before administering something you are unfamiliar with.