Bisacodyl
"Took 2 meds at 2pm with little to no water as I'm on holiday and couldn't read foreign label. BIG mistake, I barely drank anything nor ate. At 8pm had veeeery severe cramps, did an absolute volcano of a sh!t which was painful followed up with diarreha for rest of night. If you can handle screaming every swear word in the book in agony, then go for it, take 2 no more than 3 unless you want to die. 7/10 because it did its job for 20 cents."