The Laxative Potion was a magical concoction that was included in Chapter VI of Moste Potente Potions, of which a copy was kept in the Restricted Section of the Hogwarts library. The page was opposite Chapter XVI, which concerned the Polyjuice Potion. Known instructions in the book are to add two scrumples of a certain fine ingredient, another ingredient that has been used in a furnace, and Agrimony.