Hello,
I have an odd odor coming from my upstairs toilet. The smell is
sort of sulfur/stinky. It could be a vent issue. I have two other
toilets in the house (1 is exactly below the stinky one) and neither
of these has an odor. The smell seems to be coming from the water in
the bowl. I am assuming that there is a venting issue, but how would
the smell be able to come up through the water? If anyone has any
ideas what is causing this, and how to fix it, I would appreciate some
suggestions.

thanks,
Andy