Bowelbuster liquid (3.5e Equipment)
From D&D Wiki
This Potion is meant to be force-fed to enemies, not drunk by allies. Although it is more like a poison than a potion, it is still useful, because it is oderless, colorless, and can be mixed with almost anything without giving away its presence. It essentially forces the drinker to heavily defecate every last scrap of their intestines' contents with a "WOOSH". Best of all, the drinker does not feel queasy, and does not know about the consumption until it is too late. It can also be timed, to get a security guard at a building you're going to burglarize at a specific time. To time it simply insert 1 berry into the vial of bowelbuster liquid. A hollyberry delays poisons for 1 minute, while a blueberry delays it for 1 hour. The berries are dissolved by the liquid, leaving the volume identical.
This may be a joke item, but in interrogation or the example shown above, it is as useful as it is funny.
Cost: 50 gp.
It costs 25 gp and 2 Xp to brew Bowelbuster Liquid. There are no prerequisite spells, and it can also be created as an alchemical item with a DC 25 craft DC.