Designing Kitchens and Bathrooms - Unvented bathroom--should I worry?

We were told by an inspector that the plumbing for our basement bathroom is not vented. At first I thought he meant that our exhaust fan was not directed outside, but he really does mean that the toliet is not vented. He said that he has seen many bathrooms (usually illegal ones) with this problem and not to worry because there was little risk of it causing an explosion. He said the bathroom would give off the unmistakable odor of rotten eggs (methane) first, so we would definitely know that something was wrong. The bathroom really does not have that smell.:blah: But after reading a lot about the importance of waste venting, I am getting worried. How much do I need to worry? Would fixing this require a complete remodel of our bathroom? Is this something that can wait?

From a health standpoint, take a look here (http://dhs.wisconsin.gov/eh/Air/fs/SewerGas.htm) .

From a functional standpoint, and unvented toilet may not flush properly and/or maintain a proper trap seal.

I'm pretty sure it's against all plumbing and building code not to have it vented. This problem needs to be fixed!