US instructs surgeons to ask patients about cannabis use in new guidelines
regular cannabis use may worsen pain and nausea after surgery and increase the need for opioids, which often become addictive and can kill.
A man prepares a cigarette mixed with marijuana during Cannatech 2017, an annual global cannabis industry event, in Tel Aviv, Israel March 20, 2017.(photo credit: REUTERS/AMIR COHEN)