Morning marshmallows may not be the best move. The Food and Drug Administration is investigating reports of people feeling stomach pain after eating Lucky Charms cereal, according to NBC News. More than 1,300 people have complained about the morning delight on a food safety website, claiming it caused symptoms such as nausea, diarrhea, and abdominal cramps. “The FDA is aware of reports and is looking into the matter,” an official told NBC News. “The FDA takes seriously any reports of possible adulteration of a food that may also cause illnesses or injury.” General Mills, the cereal’s maker, claimed Lucky Charms was not the cause. “We take the consumer concerns reported via a third-party website very seriously,” it said. “After a thorough internal investigation, we have not found any evidence that these complaints are attributed to our products.”