Epsom salt -- the everyday name for magnesium sulfate -- can be safely used as an occasional oral constipation remedy. In recent years, however, it has become popular to use Epsom salt for "colon cleanses," also referred to as "irrigations," "colonic hydrotherapy" or "colonic treatments." Regardless of the name, these are enemas in which fluids are introduced to the colon for the purpose of physically washing it out. If you are considering using Epsom salt as part of an enema, resist the urge. It's a dangerous practice with health consequences.
Dangers of Epsom Salt Enemas
An article published in the "Journal of the American Medical Association" in the 1940s summarized the poisonings and deaths -- from the 1840s to the 1940s -- of using Epsom salt as an enema. The article explains that the danger is related to magnesium poisoning, which can be absorbed across the mucous membranes lining the colon. The typical symptoms include abdominal pain and swelling, nausea, vomiting, and in some cases death. Because of the small but real possibility of death by magnesium poisoning, today it is not considered safe to use Epsom salt as part of any colon cleansing treatment.
Oral Use for Constipation
Some packages of Epsom salt -- but not all -- include instructions on the package for use as an oral laxative to relieve occasional constipation to clear out the colon. It's important to exactly follow the instructions for two reasons. Different packages might contain different concentrations of magnesium sulfate; this means that a teaspoon from one package might not contain the same amount of magnesium as a teaspoon from another package. Additionally, not all Epsom salt has been processed in such a way that makes it safe to ingest. Check the package carefully; never use Epsom salt orally If the package says it's not intended to be taken internally.
Why Oral Use is Safer
The reason Epsom salt can be used orally but not as an enema relates mainly to the dose. The oral dose needed to relieve constipation is very small. Only a small amount of magnesium -- less than the amount that can poison an otherwise healthy person -- is needed to draw fluid into the colon and soften the stool. By contrast, enemas made with Epsom salt typically call for a much larger amount. As the "Journal of the American Medical Association" article points out, frequent use of Epsom salt enemas raises the risk of magnesium poisoning.
Alternatives to Magnesium
Because magnesium in large amounts can harm you, some people with constipation prefer not to use Epsom salt at all. Other options are products that contain milder ingredients, such as psyllium husk, a natural fiber from plants. You can avoid constipation by increasing both water intake and the amount of high-fiber foods in your diet. If you need to clean out your colon for a specific purpose, however -- for example, for a medical diagnostic test -- follow your doctor's instructions exactly. It is also wise to consult your doctor about safe ways to treat constipation, in general. Always keep Epsom salt out of reach of children and pets.