Of the weed-related visits, 31% were stomach-related, making stomach issues the leading cause of all ER trips for cannabis. And of the stomach-related cannabis visits, CHS emerged as the most common adverse event and the main driver of hospital admissions.

Monte’s findings are chipping away at the assumption that CHS is uncommon.

“CHS is certainly not very rare,” Monte told Business Insider. “We see it absolutely every week in our ER.”

Other researchers agree.