Taco Bell has temporarily removed lettuce, guacamole, and pico de gallo as a diarrhea-causing parasite spreads across U.S. states.

A foodborne parasitic disease that can cause explosive diarrhea is surging in some parts of the country. Federal and local health officials in 18 states have documented a recent uptick in cases of cyclosporiasis.

Cases of cyclosporiasis, which spreads through contaminated food, have been on the rise in multiple states since May.

Cyclospora, the parasite that infects raw produce and water contaminated with human feces, is causing illness across 18 states so far. Here's what we know and how you can protect yourself. The outbreak has been confirmed in 18 states so far.