While on a St. Charles home inspection, the drain hose for the dishwasher was found connected to the plumbing drain pipe on the wrong side of the p-trap. This can allow sewer gases to enter the drain hose and into the dishwasher and house. Just think of the odor and health problems this can create.
The p-trap is design for water to sit its belly which, in turn, stops sewer gases from entering the house. The drain hose should be connected to the tailpiece on the other side of the p-trap. The fix is relatively easy. Remove the drain hose, plug the connector, buy and install the correct tailpiece, and properly connect the drain hose to the new tail piece.