Magnesium sulfate role and use is mainly diarrhea, choleretic, anti-inflammatory swelling, the specific use of medication as prescribed by the doctor. Magnesium sulfate is the main component of magnesium sulfate heptahydrate, internal use can form a certain osmotic pressure in the intestines, so that the intestines retain a lot of water to stimulate intestinal peristalsis defecation, high concentrations of oral can promote the gallbladder to empty, produce choleretic effect, so it is suitable for use as a laxative, choleretic, in addition, can also be used externally by applying a hot compress to the affected area, to play an anti-inflammatory and de-puffing effect. The drug should be prohibited in intestinal bleeding, patients with acute abdomen, menstruating women and pregnant women group diarrhea use. When used as a laxative, if a large amount of excessively concentrated solution is taken, it can draw a lot of water from the tissues and lead to an adverse reaction of dehydration. Specific medications regarding magnesium sulfate should be administered under the guidance of a specialist, and should not be used without authorization.