If you are passing stools that are green, contain mucus and are foul smelling, this could be due to the fact that you have a bacterial stomach infection. Any stools that are foul smelling normally denote infection, whether this be viral or bacterial. The fact that your stools contain mucus is more indicative of bacterial infection though. If I were you, I would arrange with your doc to have a stool sample sent for testing. At least this way, the bacteria can be isolated and you can be given the appropriate antibiotics for your infection.
I think that it would also be a good idea for you to see your doc so that he can examine your stomach.