Bisacodyl
"This was the worst laxative I've ever taken. I don't have problems with bowel movement that often, but for the past few weeks I felt like there might be some constipation going on. I took 2 pills at 10am-ish and by 9pm cramps began happening. I first dismissed it as I often get random aches here and there and didn't thing about it that much. At the end of it I had to constantly stand up otherwise my stomach/bowels felt like they were digesting themselves. I, of course wasn't at home  (how convenient) and I had to take a taxi home because I felt like I was genuinely dying. I'm writing this right after my experience and I'm tellig you, my stomach has DEFLATED and it's so flat that it's scary. I DO NOT recomend this drug to anyone, ever"