Bisacodyl
"I've had some trouble doing a BM so I decided to take this pill. Took two, not much happened (a small BM) and I went to bed. 2:00 am rolls around and I have INCREDIBLE stomach cramps and pain coming in and out-- I felt like I was giving BIRTH! Tried to do it on my own but to no avail, ran out to the cabinet and got a third pill. Worked well in the end, but I just wonder if the two before bed was the cause of my upset stomach and crampage! 

In the end, it was totally worth it. I'm at ease for the night and that's all that matters."