Bad odor in the drain system

My dishwasher has developed a terrible smell through the drain when it isn,t run for a few days. does anyone have any ideas as to why this happens. Thanks

Hello,

How and where is the drain hose connected to?

Gene.

It may just be a pieces of food that clumped together and got stuck somewhere in the hose. Try removing the hose if you can and flushing it with water.