Synthetic cannabinoids -- often called Spice, K2 or fake weed -- have been tied to 56 cases of severe bleeding, including two deaths, across Chicago and areas in central Illinois.

All of the cases required hospitalization related to coughing up blood, blood in the urine, bloody nose, bleeding gums and other symptoms. Nine of the cases tested positive for brodifacoum, or rat poison, according to a statement from the Illinois Department of Public Health on Monday. Now, state officials are working to identify any common synthetic cannabinoid products related to those cases and to determine where the products were obtained.

There are still many questions about the illnesses; officials are not aware what exactly caused the drug contamination, but investigators and toxicologists are continuing to evaluate.