Why is potentially wanting to study medicine later on a huge problem?
Not all countries offer a graduate entry option for medical school.
In many (most?) countries, students begin med school immediately after finishing high school.
There may also be an issue with their home country’s med schools recognizing/accepting an undergrad degree from the US.
US medical schools will not accept undergrad degrees earned outside of the US or Canada (The US and Canada share an accreditation system.)