In response to Joymkr
I almost never wait for the bisacodyl tabs to take effect before starting the main enema.
I don't set there timing the bisacodyl tablets themselves. I proceed with the rest of the cleanout. I have had them kick in as early as 4 hours later, when I was retaining the third enema in the sequence. The nozzle blew out, but I WAS able to keep the enema in another minute or two till the retention time was up.
Only a couple of times have I used Bisacodyl as a stand-alone. Always 6 tablets.
First time: No food after 3 PM the day before. Next day I took 6 bisacodyl tablets at 6:30AM No breakfast. No effect at all until around 11:30, but just not hungry either. Telecommuting day so I didn't get dressed or do makeup, so no girdle. At around 11:30 I just got a lot of gas. As bad as any I've ever had. I was passing it every few minutes. At around 1:00 all that stopped, just as suddenly as it had begun. I drank some Gatorade, but still wasn't feeling much. I knew what I had taken, and I couldn't believe how little effect it was having. I was making sure to drink plenty of water.
At 4:50PM, I was just wrapping up my work, and getting ready to call it a work day, wondering if I should take an Epsom Salt and Soapsuds enema, because the bisacodyl hadn't worked.
Then, at 4:52PM: Very lucky I was only 14 steps from the toilet, and hadn't worn a girdle. If I had been 15 steps away or had to remove the girdle I wear to work, I would NOT have made it to the toilet!!!! I did get a very large, watery movement, similar to the first expulsion of a 2-qt enema, but with a little less liquid. One and done, though, I was back to normal after that.
One other time, I used it stand alone, I figured, "well, if that's how it behaves, I'll just skip dinner and take it at bedtime." That was before I was married, and I was used to having my largest meal at lunch. so I had already done the day's main meal and skipping dinner wasn't hard. I took the same, 6 generic bisacodyl tablets with plenty of water about 9:00 and went to bed about 10. I could not get to sleep! It was just like having too much caffeine late in the day. I only slept between about 1 and 3AM. By 3AM I was feeling like I had to "go" but couldn't and my stomach was in knots. I took a glycerin suppository just to get things moving. About 5AM, I finally got the same result as before. One large movement, and things settled down fast