Cyclospora is a parasite that causes a nasty form of foodborne gastrointestinal illness.
Symptoms include diarrhea, vomiting, nausea, fatigue, weight loss, gas, and cramping.
Business Insider reports a recent outbreak of cyclosporiasis has been traced to a lettuce supplier.
Lettuce from the company first infected McDonald's customers by way of their salads.
The US Department of Agriculture has now recalled numerous prepared food products that contain lettuce.