This is a problem because it is not there every day. It smells foul, like bad meat, and comes from the area of the dishwasher. The garbage disposal (next to the dishwasher) does not smell nor does the sink drain. No smell under the sink or in the dishwasher. I haven’t tried pouring anything down the drains. Could there be an S drain behind the dishwasher?? It makes no difference if the dishwasher has just been run or the dishes are dirty. Please help.