Alexander the Great was known to use aloe as a purgative after being taught about the plant’s effects by his tutor Aristotle.  Purgatives were highly valued at the time because it was believed that illness could be eliminated from the body by expelling the contents of the digestive tract.  Aloe juice can do this very effectively.  The juice can also be a mild remedy for skin disorders but this was not the main application in antiquity.  Today various unsubstantiated claims are made about the ability of aloe juice to cure digestive ailments.