OK, so I just hapened to see this diet pill offered at Walmart the other day (for $49!) and just now saw a blog post describing one teeny tiny negative side effect: you're going to need diapers! The drug is called Alli and here are a few choice quotes from their website: Because of the way in which alli works, eating meals with too much fat may cause side effects known as treatment effects. …pick a day to begin taking alli, such as a weekend day so you can stay close to home if you experience a treatment effect. If you’re getting ready to travel or attend a social event, hold off on starting with alli until the event is over. You may not usually get gassy, but it’s a possibility when you take alli. The bathroom is really the best place to go when that happens. “You may feel an urgent need to go to the bathroom. Until you have a sense of any treatment effects, it’s probably a smart idea to wear dark pants, and bring a change of clothes with you to work.†While no one likes experiencing treatment effects, they might help you think twice about eating questionable fat content. If you think of it like that, alli can act like a security guard for your late-night cravings. more: http://www.myalli.com/howdoesitwork/treatmenteffects.aspx Sounds like a fun way to spend $49!