Depends on what kind of poop. There's different songs for different types of dumps.
If you have the "Campbell Soup" shit, it's over quick, so maybe a Blur song would be suitable.
If you've got that sticky, long, crap that just keeps coming, try "The Long and Winding Road".
Buring fire crap...well there's lots of songs with "burn" & "fire". You can figure that out yourself.
Constapation? "Anticipation".
Those rocky, bolder balls of poo that splash water on the anus: "Solid as a Rock".
The multiple shrimp like/fish like: "Fish in the Sea".
Hope that helps.