magnesium salt (magnesium sulphate) in wooden spoon
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Also known as magnesium sulfate, Epsom salt is a naturally occurring substance that has been approved as a laxative by the Food and Drug Administration, according to the Epsom Salt Council. Laxatives are used to reduce the symptoms of constipation, which is the inability to pass stool at a normal rate. Epsom salt laxatives are used to promote, not prevent, digestion and the passing of stool. Always speak to your physician before using an Epsom salt laxative to make sure that it is a healthy solution for your constipation, as it can interact with many medications.

How Epsom Salt Laxatives Work

To understand why Epsom salt laxatives do not prevent digestion, you must first understand how Epsom salt works in the body. Epsom salt belongs to the category of laxatives known as hyperosmotics, according to Because salts attract water naturally, when you consume Epsom salts your stool will attract water. As a result, your stool becomes softer and larger, which stimulates your colon to pass the stool faster. This alleviates the causes of constipation, which include having a hard, dry stool or a slow bowel movement.

Small Versus Large Intestine

Epsom salt laxatives do not prevent digestion because this type of laxative specifically works on the colon, enhancing its role in drawing in water to push stool out. Digestion and absorption of most food occurs primarily in the small intestine, prior to entering the large intestine, or bowel, according to Western Kentucky University. Nutrients such as sugars and amino acids are absorbed into the bloodstream before digested matter reaches your large intestine, where an Epsom salt laxative works most effectively.


The fact that an Epsom salt laxative does not prevent digestion does not mean that you can use it liberally. Epsom salt laxatives are considered a short-term solution for constipation, according to This means that they are not considered a solution for chronic constipation. Also, Epsom salt laxatives can cause side effects, such as bloating, cramping, diarrhea, nausea and gas. Because Epsom salts rely on water to work properly, it’s also important that you drink plenty of water when taking it. recommends mixing one dose in 8 ounces of water.

Laxative Misconceptions

Epsom salt laxatives can produce results within 30 minutes of use and up to six hours, so they are often overused as a way to lose weight. However, because laxatives do not prevent digestion, the calories are still absorbed. Instead, the weight loss comes from losing water weight and passing stool quickly. Laxative overuse can lead to intestinal damage, reports, so be sure to contact your healthcare provider if you feel you are unable to have a bowel movement without using an Epsom salt laxative.