Milk of magnesia
Milk of magnesia is a saline-type
laxative. The magnesia pulls a saline solution from the bloodstream; this excess fluid produces a flushing effect within the intestines. Available over-the-counter, it is most commonly used in alleviating
constipation, but can also be used to relieve indigestion and heartburn, though the
diarrhea side effect usually precludes this usage.
[1] The most common brand name is
Phillips' Milk of Magnesia.