While I won't necessarily say I'm part of the "be careful what you wish for" crowd...
Ever since I did my stomach in with an ulcer once with too much NSAIDs and again overdoing it, I occasionally get unexpected surprises. Several weeks ago, I was in Lowes, and what I thought was just gas might have been a little more like a bottom "sneeze". Two days ago, in a courtroom for jury duty, I felt the need to fart but also my stomach churning, so I had to sit there and hold that back which made it really hard to pee at the same time. I left feeling like I was going to explode from both ends, but that was the lesser of two evils. Rather not shit myself in a courtroom with my supplies down the street where I had to park.
Anyway, a little laxative play isn't going to hurt you most likely. Just don't do anything too crazy. Try a swig of mineral oil first I'd say. It's cheap, pretty much tasteless and doesn't have long lasting effects. It doesn't work too great for diapers because the oil itself doesn't get absorbed, but it'll definitely give you the sort of... "surprise!" results you want