The International student advisor once told me that the only exception that allows one as an F1 visa holder to stay in the United States without transferring to another school or changing to another non-immigrant status is a medical leave of absence. Could somebody please point to me where this is officially written, and for how long is this exception can take once granted? if she was granted this permission lets say for 7 months without attending classes and travel out of the country, will she be barred from re-entry for 3 years? A sick friend of mine would like to invoke that but has no clue where to start from. Any knowledgeable comment is welcome.