You are going to find that bisacodyl(Dulcolax) is extremely effective but very slow. Taken stand alone, it takes at least 6 hours, and can take as long as 9 hours.
In a complete cleanout, I essentially clear the stomach by fasting, the large intestine with enemas, and the small intestine with 30 mg bisacodyl, taken all at once, about 90 to 140 minutes before the first enema. Typically kicks hi in 3 hours or so.
When you take bisacodyl, don't be surprised if you experience no effect at all for the first 90 minutes or so.
The first effect will be a suppression of appetite Then after that, about 2-3 hours in, you'll get some gas, but nothing else.
When it finally does kick in, it does not really give any warning, and KICK is a good word for it! You don't want to be more than about 20 steps or so from the toilet! I was 14 steps, and was wearing a simple Mumu type dress with just simple panties and an everyday bra. Had I been 16 steps away, I would NOT have made it on time!!!