What should I do if a glycerin suppository does not work? Enema?

Maybe. You can try a fleet mineral oil enema. As long as you dont have an infectious process in your belly and are sure you do not have a bowel obstruction from prior surgery or some other cause, go on liquids and take 1-2 tbsp of milk of magnesia (magnesium hydroxide) every 12 hours and you can try 1-2 tablespooons of mineral oil every 12 hours, until you have had a bowel movement and feel emptied.If doesn't resolve with abo.