This is called colonic lavage. The prep washes everything out, also kills bacteria due to wash out and osmotic destruction, plus
entero toxin removal.
There is evedience that people have gone into remission just from prep, this I would guess depends on the health of your colon.
Please also note that people can get inflammation from irritation due to the prep, especially phosphate of soda.
Old Mike
UC 1980, and I am getting real old.