Do you need to cleanse yourself of negativity or frustration or a negative behavior? If the bathroom is filthy or unusable, then you are not properly relieving your frustrations. You probably tend to hold in your thoughts or opinions when something is bothering you rather than relieving yourself of it. This dream is showing you that your psychological plumbing is backed up because you are not properly flushing away that which bothers you. In other words: Don’t hold in your “crap” or you’re gonna start to stink!!