You suggest - but do not actually say so - that the dishwasher is failing to drain.
On many machines you can get to the impeller of the drain pump from inside the washing chamber - remove the filters and undo the single torx screw on the impeller cover.
You will often find all sorts of crud jamming up the blades of the pump - foil - lemon pips - bits of bone etc.
Tweezers will help.
Good luck...
March 2015