Rhode Island Rainbow 

The act of receiving a Diet Coke enema and carefully inserting Mentos into the anus right after the sugary butt chug. It is very important the participant bends over to produce an arch (or rainbow) of shit/Diet Coke as the fountain of carbonation rockets out of their anus.

The stripper at the gentleman's club did a Rhode Island Rainbow during her routine. It was so hot.

Rhode Island Rainbow by Giggling_santa May 20, 2020