Where you need to go to the bathroom so bad thAT THat you could die. You sit on the toilet and.......
1........the poop disapears
2........you think your pooping then go to flush the toilet and nothings there.
3........ you had a misterious ghost poop
4........or your butt hole is just cloged
After you unload your watse (for the weak-minded, your crap) you take that Charmin Ultra (again for the simpletins, your poop paper) and cleanse your anal (for urbanites, your pooper) and after looking at your art, only THEN you relize, there is no residue there! (for the average-Joes, no poop on the paper)
The double ghost poop is when you go to take a shit and there is nothing on the toilet paper when you wipe your ass, but further more there is also NOTHING IN THE BOWL.