There's no fill option in my OIP. I tried attributes to solid but doesn't change it. Its a symbol I created (a sideboard cabinet) done by extruding and joining all elements as a symbol.
In OIP I just have to open the symbol to an extrude (double clicking) and get the options for sketch, Map type, radius, start/end cap, scale, rotation, update, mapping, override radiosity (all under the render tab).