Magnesium hydroxide or Mg(OH)₂ is also known as milk of magnesia. This liquid is taken orally and contains the naturally found mineral, magnesium. Charles Henry Phillips, in 1880, came up with the original formula. He sold the concoction under the name "Phillips' Milk of Magnesia". Overview of Magnesium hydroxide Magnesium hydroxide is an alkaline suspension. When it comes in contact with anything acidic, it neutralizes the acid. Hence, it works to cure irregular bowel movements and indigestion as it combats stomach acid and neutralizes it. Hydrochloric acid generated by cells in the stomach often leads to heartburn, indigestion, stomach ulcers, and constipation. Magnesium Hydroxide for Constipation Constipation is irregularity in the digestive system due to which a person experiences hard feces, which are difficult to expel. It is not a disease, but a condition which can be caused by a number of factors. This condition usually occurs due to over absorption of water in the colon. Having bowel movements less than thrice a week is also termed as constipation. When magnesium hydroxide is taken orally, it behaves like an antacid. The hydroxide curbs the overactivity of the hydrochloric acid generated in the stomach. It is recommended to have magnesium hydroxide at bedtime or as directed by the physician. It can also be given to children, but should be given under medical supervision. Magnesium hydroxide scores over stimulant laxative, also called non-saline laxative. Stimulant laxative induces intestinal contractions which can be harmful for the bowel in the long run. When taken in large quantities, magnesium hydroxide behaves like a saline laxative. As a laxative, it stimulates intestinal mobility and helps flush out toxins from the body. The magnesium content draws water and salt to the intestinal tract from the surrounding tissues using osmosis. Higher quantity of water in the intestinal tract helps soften the feces and increase the fecal volume. It also helps stimulate the nerves in the intestines. It can take anywhere between 6 to 24 hours for milk of magnesia to work depending on the dosage of the laxative used. Magnesium hydroxide is a chalky tasting liquid that comes in bottles. It is found in its original form as well as flavored and non-flavored forms. The flavors available are cherry and mint. If you are not a big fan of the liquid, there is a chewable tablet variant which is also available. It is also available in capsule form. For better results, it should be taken either with a glass of water or juice for effective absorption. Side Effects It is important to note that magnesium hydroxide has some side effects. Patients who are affected by chronic kidney diseases need to consult their doctor before they take this laxative. The kidneys excrete magnesium because high quantities of magnesium can wear out the kidneys and cause magnesium toxicity of blood. At the same time, use of magnesium hydroxide in general, is not recommended for a prolonged period of time. It can react with antibiotics, hence, consulting your health care professional is recommended. Nursing and pregnant women should consult a doctor before they take a dose of this laxative. People on magnesium restricted diet also need to consult their doctor. In case of rectal bleeding or no bowel movement after consumption of a magnesium hydroxide preparation, contact your physician immediately. If an overdose is observed, contact poison control center immediately. Magnesium hydroxide as a laxative should be taken in prescribed quantities only. It should be used only occasionally, and if it has to be used for a prolonged period of time, it should be done only under medical supervision. Taking it for a very long period of time can create too much of magnesium in the body with resulting side effects. Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice.