NEW YORK (AP) — In the past year, the U.S. has seen a jump in frequent marijuana users going to the hospital with a nausea and vomiting condition, according to a report released Thursday. Hospital emergency room diagnoses of the condition, cannabis hyperemesis syndrome, rose 16% from last October to May of this year, federal researchers found. The syndrome — seen in people who frequently use marijuana, especially smokers — is characterized by recurring nausea, uncontrollable vomiting and excruciating abdominal pain. Past research has suggested that an estimated 2.75 million Americans suffer from it each year, and that hospital emergency room visits have been rising as daily recreational marijuana use has increased. In the new paper, researchers at the CDC’s National Center for Injury Prevention and Control looked at emergency room data from about 7,500 healthcare facilities across the country through May.