Public health officials are expanding their investigation of an E. coli outbreak linked to romaine lettuce.

The initial warning urged consumers to avoid chopped romaine, but there are new concerns says Illinois Department of Public Health spokesperson Melaney Arnold.

Symptoms include severe stomach cramps, vomiting and bloody diarrhea says Arnold.

There have been 53 cases of E. coli infection in 16 states so far with just one from Illinois.