I've taken Epsom salt as directed on the drug facts label 3 times, ever, and all three times I probably avoided an urgent care/clinic visit by doing so.
If you're ever so severely clogged up that you're approaching a week without - Epsom salt will, in fact, work. It works so well that I'd recommend pre/probiotic foods for a couple days afterward. It completely cleans you out.
Otherwise, I agree. You have to know why you're clogged, too; if you got no clue, go see a Dr.
constipation is one reason, but also just a temporary, painful blockage for whatever reason. Epsom is like drano for your intestines. The dosage information is on all epsom salt packages designed to be used this way. Obviously don't ingest like, lavender scented bath salt (Sitz salt, whatever)