Quote Originally Posted by geminigirl
He collected a urine sample and it is being sent to a lab to be tested. My question is how long after marijuana is smoke will it show up in urine. My son is very athletic with no body fat, assuming he is telling the truth that he hadn't smoked for a few weeks, I am wondering if the test will come back positive.

THC tests can produce positive test results even when a person hasn't smoked for 4-6 weeks, depending on how heavy their usage was. Your son could very well be telling the truth, but the test could still come back positive.