I have read up on existing questions on this issue, and I understand it is a fairly common issue.
Unlike some other people, my kitchen sink hasn't been clogged, and the garbage disposal works fine. But there is always water at the bottom of my Frigidaire dishwasher (model FFBD2411NS), as high up as going up 1 inch over the bottom.
I called in a maintenance technician from the dishwasher warranty contract company, and he checks the dishwasher's drain hose and tells me the dishwasher works alright, and it's my kitchen sewage that's clogged. I remember seeing him unplug the dishwasher hose and water flow out of it from the dishwasher, which according to him shows that the dishwasher should drain properly.
Despite I don't see any clog, I tried some clog remover liquid. I also called in a plumber and had the kitchen drainage checked, but was told my kitchen sink wasn't clogged.
Now water still backs up, giving out a strong repellent odor, and we can't use the dishwasher as a dishwasher because of this. We have been using it as dish racks.
As @manassehkatz suggested, I am putting up a picture showing the drain hose path. There doesn't seem to be a high loop. Should I create one by elevating the hose?