A massive E. coli outbreak caused agencies to ask the entire nation to toss their romaine lettuce. 

Both the Food and Drug Administration and the Centers for Disease Control have asked Americans to discard all romaine lettuce following an outbreak of E.coli that's been traced back to the leafy green. Earlier this week, the agencies reported more than 53 illnesses and 31 hospital-related treatments for E.coli sickness in 16 states across the nation. 

While health officials have been able to trace the E.coli-tainted romaine lettuce back to Yuma, Arizona, the first waves of warnings earlier this week weren't as stringent as they are now. Did you eat romaine lettuce before you heard the warnings? There are a few telltale signs you can watch for

According to the CDC, this widespread outbreak has been linked with E. coli O157:H7, a strain of the infectious virus that could cause a laundry list of symptoms. The main side effects, and most worrisome, involve diarrhea, crippling stomach cramps, and chronic vomiting

If you were unfortunate enough to eat contaminated romaine, you would start to notice these symptoms between two and eight days after eating the meal. The food safety agency says the sickness should last no more than a week, and is treatable with a trip to urgent care or your medical provider. 

Some of those affected by this romaine outbreak have been victims of a more serious side effect of E.coli, hemolytic uremic syndrome. It's a rare form of kidney failure, and younger children, the elderly, and those with weakened immune systems are at greater risk to develop this serious illness. For more information on what's known as HUS, click here.

The CDC and FDA are asking all home cooks to immediately discard all romaine lettuce and grocery stores have pulled products from shelves indefinitely. It could be a while before romaine lettuce is safe again—we'll update this story with more information as it becomes available.