The Centers for Disease Control and Prevention says there are multiple reports of people falling ill after consuming tainted salad.
The 23-cases have been reported in midwestern states.
The CDC says the pre-packed lettuce sold at grocery stores is tainted with the parasite Cyclospora.
Those afflicted get symptoms including stomachache and diarrhea around two weeks after being exposed.
The product is sold under different brands at Walmart stores.
The producer is Fresh Express.
The product was sold in at least 12 states including Indiana and Illinois.
The details about the product names and the recall are in a June 25th post on FDA-dot-Gov.