Here are my thoughts. Really appreciated their approach to whole person care, and I think they generally breed a group of physicians who have a decent perspective and tactful personality.
That said, you need to understand they take a hard stance on drugs/alcohol. They are a religiously affiliated institution and it permeates a great deal of the environment there. While they won't kick you out, they have required physicians and medical students to undergo mandatory rehab, etc. As for the specifics of drug testing, I can't for the life of me remember taking a drug test. But I do know students who got in hot water. I did two away rotations and both required me to take a urine drug test, so I would not be surprised if LLU does it for visiting students.
But I'm going to be straight up with you man, if you are asking this question without considering cleaning up for the first several days of a brand new away rotation, you need to consider whether a place like Loma Linda is going to be a fit for you.