Common Dehydration.

Expert advice for Deys Milk OF Magnesia Liquid
Avoid taking a Deys milk of magnesia for more than 1 week, unless prescribed by the doctor, as it leads to dependency on the laxative action to produce a bowel movement.  Together with Deys milk of magnesia, fiber rich diet containing whole grain bread and cereals, bran, fruits and green leafy vegetables, is essential to maintain healthy bowel function. A Deys milk of magnesia should preferably be taken at bedtime because it requires 6 to 8 hours to show impact. Notify your doctor if you are on a low-sugar diet because the Deys milk of magnesia contains sugars. Take Deys milk of magnesia after 2 hours from other medicines, as it may interfere with the absorption of other medicines.