Most of the dishwashers having the filter where the food particles stuck and it prevent the blocking of drain. Those food particles in the filter make a cause of smell in your kitchen.
Firstly, you have to take out the filter
Wash the filter with hot water and soap and there will be no food particles remain in the filter.
You have to sure that there are no food particles in the drain as well, washout the drain before you re-install the filter.