How does Milk of Magnesia work?
Is it safe to take milk of magnesia? How does it work? I don't like the idea of using any medicine, so I've avoided it, but my doctor says that I have to prioritize keeping regular bowel movements. If I do take milk of magnesia, what side effects can I expect? Are there better laxatives?
Milk of magnesia works by creating an osmotic load in your colon. Essentially, since the the main ingredient of MoM, magnesium hydroxide, is poorly absorbed through the GI system, it ends up greatly increasing the solute concentration in your colon. this increased solute concentration ends up pulling water into the colon by osmotic force. the increased water inside the colon stretches the walls of the colon, which sends a signal throughout the nerved of the gut that it is time to evacuate the colon. this perpetuates a contractile muscular wave (called peristalsis) and ultimately results in a bowel movement that is normally loose and watery because of all the absorbed water into the lumen of the colon. This is NOT an effectively way to manage your bowel habits. milk of magnesia can cause dehydration as well as many other serious electrolyte imbalances (eg, low potassium levels which can lead to fatigue as well as serious heart conditions). Milk of magnesia should be used only on rare occasions for relief of prolonged constipation. a much more effective way to manage regular bowel movements is by drinking at least eight 12 ounce glasses of water a day and by eating foods high in fiber as well as supplementing your diet with additional fiber as needed. I recommend high fiber, whole grain cereals and foods as well as with supplemental metamucil (soluble fiber) to be used on a daily basis to improve bowel regularity.