"...acts to pull a salt or saline solution into the intestines
from the blood...."
That is the origin of it's laxative action in people. In
the doses normally given (a couple of tablespoons/100 lb human) it is a fairly
mild laxative. I do not know how much would have to be given to have the
same effect in people. If enough were given to a horse to do this to a
measurable degree, it would not be a good thing during an endurance
competition.
Before it gets to the small intestine, it will neutralize some
of the acid in the stomach {(Mg(OH)2 + 2HCl=> MgCl2}. I believe that
this is the reason it is given along with other electrolytes during
rides.
Ed
Ed & Wendy Hauser 2994 Mittower
Road Victor, MT 59875