This story is adapted from the Slatest newsletter. You can sign up here to get it in your inbox every day.

An unpleasant sensation is sweeping the nation: vomiting and explosive diarrhea that can last for weeks. Caused by Cyclospora, a foodborne parasite, the outbreak has spread to at least 34 states. But public health officials finally appear to be zeroing in on what’s causing it. Here’s what we know—plus some tips for enjoying a weekend free of gastrointestinal distress.

Gross. Where does this outbreak seem to be coming from?

At first it was a mystery. But now public health officials are eyeing lettuce—specifically shredded iceberg that Taylor Farms, a California-based vegetable supplier, distributed to Taco Bell restaurants in at least five states. Taylor Farms said today that it would recall certain products after hearing from the Food and Drug Administration. Officials who spoke to the New York Times say a single supplier in Mexico originally grew the offending produce.

How bad is the outbreak?

If you’re unlucky enough to have gotten the bug yourself, pretty bad! The illness generally isn’t deadly, but diarrhea—which if untreated may last a month—can cause dangerous dehydration. In terms of case numbers, things aren’t much better. This is already the U.S.’s largest recorded outbreak of cyclosporiasis, the hard-to-pronounce illness Cyclospora causes. According to the Centers for Disease Control and Prevention, more than 1,600 people fell ill after eating at Taco Bell; we know........

© Slate