I was diagnosed with severe gastroparesis, and also esophageal spasms, and chronic constipation. So, I haven't gone in several days, despite daily Lizness and Miralax. I am currently doing prep for colonoscopy. I already drink massive amounts of water, so not concerned about dehydration. So I managed to get down a full bottle of magnesium citrate (almost barf every time) along with other meds, plus nothing solid for the day before that (liquid only Friday and Saturday). I also drank more water, coffee, juice... Took the mag citrate yesterday at 5 and so far the sprints to the can has only resulted in a couple of foul smelling toots. I still have more prep to do later today, but shouldn't the mag citrate have kicked in by now? I'm not that uncomfortable, having little rumbles in the gut for about 4 hours.