Suppositories work super well even for those who have a low sensitivity to laxative products - they don't rely on the digestive system at all, and instead irritate the bowels until your body lets go. Enemas, of course, are a brute-force way to do this too, but are a lot to work with. In-terms of laxatives, Magnesium Citrate is the gold standard for good messing, but it relies on your digestive system and in the case of some people does nothing at all.