Bisacodyl
"Horrible product I took it at night about 7pm woke up with stomach hurting by 4am went to use bathroom but all that happened was major cramps and stomach in so much pain it was seriously as bad as labor contractions I was in so much pain I ended up throwing up three times because this pain came and go non-stop for about  4 1/2 hours worst pain ever. I did have a couple bowel motions but seriously not worth the horrible stomach pain and cramping, throwing up  and sweating because of it. Better off trying magnesium. My stomach region is now a day later still sore."