Is vomit pure or impure? What should the person every time he/she vomits? Is it compulsory to wash the mouth?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions. Vomit is impure whether the vomited food has already changed or not. This is the opinion of the majority of Muslim scholars. Imam al-Nawawi wrote in his book al-Majmu'a: There is an agreement among scholars that vomit is impure whether it is from human beings or animals. However, al-Malikiyah are of the opinion that vomit is considered impure only if the food or drink has already altered/changed. Therefore, you are obliged to wash your mouth to remove the remnants as well as any place of your clothes or body that got stained with vomit. Allah knows best.