Remember in the late 90s when Lays put out those diet chips that made people shit themselves? I do, though I won't confess that they gave me "loose stools."
From Wikipedia:
Lay's WOW Chips were fat-free potato chips produced by Frito-Lay containing Olestra. They were first introduced in 1998, and were marketed using the Lay's, Ruffles, Doritos, and Tostitos brands. Although initially popular, charting sales of $400,000,000 in their first year, they subsequently dropped to $200,000,000 by 2000, as Olestra caused "abdominal cramping, diarrhea, fecal incontinence ["anal leakage"], and other gastrointestinal symptoms" in some customers,[1] warnings were required to be included on the packaging, with the WOW bag bearing a warning that read, "This Product Contains Olestra. Olestra may cause abdominal cramping and loose stools. Olestra inhibits the absorption of some vitamins and other nutrients. Vitamins A, D, E, and K have been added.