Bisacodyl
"I took one dulcolax around 5:30pm with a glass of water and a sandwich and came online here preparing for the worst time of my life. Hadn't gone in 5 days and was starting to feel a bit of pressure/discomfort. About 2 hrs later, one solid (but slightly softer) BM comes and goes and now 5 hours post pill, the only effect I'm dealing with is a grumbly stomach and very mild cramping, no more than a 2 out of 10 on the pain scale. I feel 50x better and this mild post-pill/post BM discomfort is definitely worth it given the huge relief. 6-12 hours to work? More like 1.5-2. My suggestion would be to drink a good amount of water with it and eat if possible, and start with just one pill! I'm a 105 lb female, 20 yrs old. Don't take 2-3 at once!"