Seidlitz powders are a popular laxative that come in a powdered form. They consist of two separate components that are mixed with water to form a fizzy, slightly salty solution that helps to ease constipation and promote bowel movements. While Seidlitz powders have been around for centuries and are widely used, there are many other synonyms for this product. These include effervescent salts, soda powders, laxative salts, and saline laxatives. Each of these terms refers to the same kind of products that work by increasing the amount of water in the colon, which makes it easier to pass stools and relieves constipation.