The process for me varies based on when the scope is.
If the scope is in the morning, then I stop eating at lunch time the day before, even prior to that though I eat "light" foods (foods that don't typically like to hang around..).....
I don't do any mag citrate either.....
A full colonoscopy prep is too much and way, way overkill for us with J Pouches.
You said the doc told you, you had too much stool in your rectum? Did they leave your rectum totally in place?