Bisacodyl
"DO NOT TAKE THIS!!! I've been losing weight and trying to tweak my meal plan but I sometimes don't get enough fiber and then become constipated. I took a single dulcolax before bed and woke up around 11:30 in extreme pain. I went to the bathroom and had a BM but immediately after I got so warm. I sat on the bathroom floor thinking I was going to die. I then proceeded to vomit. I will never take this again."