Dave, there is an Italian restaurant downtown Du Quoin on Main Street. The place is called Algoni's. Really nice place but not too swanky, food is well above average.
We've eaten there a few times when we've been down to the Fair and the Labor Day weekend races on The Mile.
Good food and not too pricey. This is the link to their menu webpage.
http://www.alongis.com/menu.php They have wine and beer, but not sure if they serve mixed drinks.
Scotshot might know of another Italian restaurant in Du Quoin but we're not aware of any.
If you are looking for a good place for breakfast in Du Quoin there is a place called Kalin's Cafe' not far from Algoni's that is pretty good. It's on Main Street as well but on the opposite side of the street from Algoni's.