If I am a Colombian Citizen with a multivisit visa, and I don't have the actual visa because it is attached to an expired visa which is forgotten in the U.S. -
What are the chances of re-entering USA? Is the visa information in the computer or is it useless without the physical stamp?
Did you get your new Colombian passport while in the US? Otherwise it suggests you left without your passport? How is that legal?
In any case if you had a B2 in an expired passport, it is still valid (I came to the US with two passports, one expired but has my US visa). I was just lazy and did not transfer it, but there is no problem doing so. You just might have to explain your passport-in-the-US situation.