Whirlpool Dishwasher - Smell when draining & red/orange grime consistently after washing (even after cleaning drain hoses multiple times)

[paulferree]

I have a Whirlpool Dishwasher Wdf520padm7

Fairly recently we've noticed that often after a wash there is a greasy feeling red/orange grime after the wash cycle is complete (see attached picture, probably the worse we've ever seen it). We don't eat greasy foods at all and we rinse our dishes fairly well before putting them into the washer (and we don't eat a lot of spaghetti and cant think of what the red/orange is coming from). 

Additionally, I've had a rotten egg smell coming from the garbage disposal when the dishwasher is draining and sometimes when I open the dishwasher door.

I'm pretty handy and have cleaned the drain hoses multiple times, regularly clean the filter and wipe down the inside, and had to replace the drain pump about a year ago. 

I'm going to take the whole thing out today (again) and remove the pump assembly to see if anything is stuck in there causing it to stink (it definitely seems to be draining properly).

My wife is ready to get a new dishwasher because of the smell, the dishes seem to come out clean fine so I'd hate to give up on it for something that seems fixable. 

Any tips on where to start figuring out what the source issue is?