Confused on how osmotic laxatives are supposed to work.... Are they supposed to give you diarrhea or gently draw the water out of your body to soften pooh and make you have regular solid bowel movements without diarrhea and urgency?

First time I took bisacodyl and PEG3350 daily powder was exactly the day after drinking a gallon of colonoscopy prep to clear my bowels till the stool was watery and yellow (sorry TMI). When I took the osmotic laxatives it continued my severe diarrhea. However, I stopped all medication for 2 days (had zero bowel movements), started eating normal food and restarted the osmotic meds. The day I restarted I had continued having zero bowel movements. Next day were the pellets but softer than I've ever had in the past. Now I'm passing regular sized soft stool, no pellets. So I'm confused... which is the way it's supposed to work? Diarrhea or regular soft bm's? I'm worried I might be too backed up if regular bm's are not the norm.

What was your experience on the osmotics?