Earlier this week, Jennifer Lawrence experienced such severe stomach pain she was forced to go to the hospital.

"The Hunger Games: Catching Fire" star told David Letterman on Wednesday that she had to cancel several public appearances, including an L.A. premiere afterparty, over the abdominal pain.

She explained to the late night host: "I thought I had an ulcer, but it turns out it was a 'fulcer.' I went to the emergency room... I just had this really bad pain for, like, three weeks. And you know you can only s**t your pants so many times a day before you go to the emergency room, before you're like, 'I need to go to the hospital.'"

Following her interview with Letterman, Lawrence attended the New York City premiere of her film, and when asked how she was feeling, she answered: "Good," before turning around and snickering, "Just gassy."

Her film hits theaters this weekend. It centers on Katniss (Lawrence) and fellow tribute Peeta Mellark (Josh Hutcherson), who begin a "Victor's Tour" of the districts. A rebellion is brewing, but the Capitol is still very much in control as President Snow prepares the 75th Annual Hunger Games.