A person in my family is having problems ...

I have a person in my family that works a lot, does not have friends who use drugs, does not spend wildly, does not disappear, even so I have doubts due to some symptoms, whether or not drug. I always asked him and he tells me not to. But once a week he gets sick, vomits a lot, gets soft, dysentery, sweating, gets locked up and stays around for two to three hours in the bathroom, saying that he is ill and that he ate badly. What I do, I have doubts. He goes through routine examinations in the company and has nothing, even though which exam should include the use of drugs? That's what i do? Is it stress?
Expert answer:

You have to convince him to go to the doctor and get help for whatever is going on, but the decision is for that person, no one can take anyone's right to decide on his own life, even if the choices are not so good.