Toilets, Sinks, Showers, Tubs and Disposals - Possible Toilet Flange Leak

I try to do things myself, but have figured out if it ain't broke I shouldn't try to fix it. Anyway, have kept track under the house around a toilet. Can tell it leaked at one point(discolered wood, not rotted), is there any good way to determine if it is still leaking slowly or is it best to just replace the ring. Thanks in advance.

I would say flush the toilet several times and re-check the area. Also, if someone else could do the flushing while you inspect, you'll see exactly if and where the leak is.

Let us know what you see.

Can you move the toilet around on the floor at all? If so, then you should pull the toilet, check the toilet flange not rusted out and screwed tight to the floor and reinstall the toilet.
If it is tight to the floor, follow jim-connor's post.

Its firm to the floor. Checked it last night with someone flushing, no sign of leaks. I did forget to mention, which I know is bad that I noticed it last spring when we moved in and kept meaning to 'check into it'. Anyway doesn't look like the stain has spread, just wondered if it was a drop or two leak per flush and if so, how do you tell, or if it was an old leak. Previos owners redid bathroom about three years ago. Thanks for everyones help.