So I have this friend...his dishwasher is about 8 years old I'm guessing. A couple months ago the discharge hose sprung a leak and was replaced from the dishwasher to the sink drain. The leak/hole was caused by the hose rotting away apparently from age. Anyways, the replacement hose was routed the same way with a high loop before going into a Y drain(above the trap).

Well, his wife keeps complaining about the standing water in the bottom of the dishwasher. She's been complaining about it since it was first installed so it's not a recent issue but rather long term. He's not too familiar with how dishwashers operate so he thought that it was just normal to have some water make its way back from the slope/length of the hose. When I look inside the dishwasher, there is at least an inch of water standing at the bottom. When running a cycle, water does exit into the sink drain, but there is a lot left over inside the dishwasher.

I don't have a manual for this dishwasher, maybe he can find the owner's manual, but I don't know if that would help much in this situation. Since this is long term problem and the discharge hose was just replaced (ruling out a clog past the dw) is there anything I can check internally or underneath this unit?

Thanks in advance for any help

Here are your parts
Parts for Maytag MDB9750AWQ Dishwasher - AppliancePartsPros.com

Perhaps the back-flow flapper valve (item 16 in section 03) is mispositioned or missing.
Could be he knocked it loose when attaching the new hose.
The below shows where it should be located.
Part number: AP5272754

Ok, I took off the drain hose and found the flapper intact and in the position shown in the picture. Also looked for clogs and everything is clean. Should I take this whole piece off (drain pump) and check the other side? It's amazing how much water drained out of this thing when I removed the drain hose.

I manage to fix the problem. I purchased the drain pump and replaced it. Although I think it may have just been the flapper. Once, I had the drain valve off I could see the flapper not returning all the way back to cap off the drain. But it wasn't worth my time to take the new drain pump off and put the old one back on just to try a new flapper.

Thanks again for the help.