We recently moved into a new home, in which I completed much of the finish work myself. One of the tasks I took on was installing all of the appliances. After about a month, our dishwasher has developed a foul odor. The odor occurs just after the dishes are cleaned and it stays with us while dirty dishes are being loaded into the washer. We wash them about every 2 – 3 days. We have cleaned and sanitized the washer several times. Still smells! Did I mess something up during installation? Help me make my wife happy!
It sounds like you're dealing with biogas.
Try disassembling the spray arms. There's a nut you can unscrew to pop them off. The spray arms have little ports in them, and they sometimes get gross. Look for black gel or goo that sometimes attaches to them, and flush it out. Use super hot water or soak them in water with bleach.
Make sure you also thoroughly wipe down the door seals with a bleach and water solution, because sometimes food gets stuck behind those seals. This also happens on washers - another common place for odors.