Well, it's not good, at all. I would first attempt to snake the drain line and see what happens. If you don't succeed, next step would be having a pro do the same thing. If you can open a clog, a bit of detective work on what exactly the clog is composed of is helpful. For example, tree roots and dirt and a lot worse that hair and soap build up. At that point the line can be inspected with a camera scope. Since exterior drain lines in your area need to be deep to provide frost protection, if your drain is creating a wet spot outside, I would guess that the pipe is broken pretty high up, like immediately under the slab. A lot of these leaks never really show signs of wetness inside the home, since slabs are typically placed on a thick layer of small gravel that drains freely. Unfortunately, given the upcoming lovely weather in Chicagoland, this is a problem that is now a pretty high priority, since you don't want water under a slab that can freeze solid, and cause frost damage, which can include severe structural damage, even in concrete. Hope it all works out, this sounds like it could become expensive.
