I've been having severe recurrent heartburn/acid reflux, so my doctor referred me for an endoscopy and colonoscopy to determine the cause. I'm undergoing the colon cleanse process thanks to Moviprep. I was worried that I would never end up on the toilet but it finally started to take effect 2 hours after the second liter dose. I'm not "clear" though, but hopefully, I will be by the time my appointment time arrives in 6 hours.
Check out the Moviprep introduction video in case you plan to get a colonoscopy.