Questran is mainly used to treat high cholesterol levels in the blood, as it helps reduce them to prevent heart and artery diseases. In addition, this drug is sometimes used to treat certain cases of diarrhea resulting from problems related to bile or digestive system disorders. Questran can also be prescribed for people who suffer from itching associated with bile duct obstruction, as it helps relieve symptoms. However, Questran must be used under close medical supervision to avoid any side effects or unwanted interactions.