So, back to your mothers case, Paraboy; if she get loose bowels from taking magnesium, she probably have an utilization problem.
"A healthy gut environment is necessary for proper absorption of magnesium from the diet. Irritable bowel syndrome, leaky gut, candidiasis and other gut disorders can severely limit the amount of magnesium that the body will be able to absorb. Older adults often experience decreased stomach hydrochloric acid production, which can impair mineral absorption in general. And with so many treating their “heartburn” with antacids, a healthy digestive environment is hard to maintain."
Here is the magnesium oil mentioned; The one I take is from Utah, the salt lakes. It contains quite a bit of boron and lithium as well, and most other trace minerals. Doesnt taste very good, but it is suggested to put it in food, as bone broth for instance. I find it easier to take with some salt in the water as well.
Mine contains per half teaspoon;
266 mg magnesium
740 mg of chloride (bromide-detox)
1,5 mg of lithium (mind stabilizing)
1 mg of boron (to retain magnesium)
Can be used transdermal. And to re-mineralize RO or distilled water.
"Loose stools indicate you are not absorbing the magnesium, but that it is acting as a laxative. When the magnesium travels through the intestines in less than twelve hours, it is merely excreted rather than absorbed. If you find you cannot overcome the laxative effect by varying your dosages, you may want to try an oral supplement that is chelated to an amino acid, such as magnesium taurate and magnesium glycinate, which some consider to be better absorbed than the salt forms and less likely to cause loose stools. For those who need a little help with digestion, such as young children, older adults, and anyone with reduced stomach acid or bowel dysbiosis, consider homeopathic magnesium, also referred to as tissue salts or cell salts. Magnesia phosphorica 6X is the appropriate dosage, and it works to usher magnesium into the cells where it belongs. It is also indicated as a remedy for muscle spasms and cramps of many varieties. Mag phos can help reduce and eliminate loose stools while you are supplementing with oral magnesium, giving you a positive sign that your body is indeed taking the magnesium into the cells.
Yet another option for oral magnesium supplementation is ionic magnesium in liquid form, such as that offered by Trace Minerals Research. This is a sodium-reduced concentration of sea water from the Great Salt Lake in Utah. Only about a teaspoon is needed to deliver about 400 milligrams of magnesium (along with seventy-two other trace minerals), which should be taken in divided amounts during the day. I recommend adding this to soups (made with bone-broth bases of course) as the strong mineral taste is hard to take straight. You can also add this to spring and other drinking water to up the magnesium content and use it in cooking. By “micro-dosing” your food and water in this fashion you greatly reduce any laxative effects a large dose of magnesium might elicit." http://www.westonaprice.org/vitamins-and-minerals/magnificent-magnesium