help...epsom salt-canada

I been wanting to do the liver cleanse and it requires Epsom Salt. I live in Canada and been to Shoppers,Superstore,Walmart,Safeway. All I could find were the Epsom Salt for baths,in the pharmacy usually in the First Aid section,I've checked the spice aisle too. Most say." Do not use internally." Where do I find them in Canada?? Or do I order online??