Hunger Games: Catching Fire star Jennifer Lawrence had a very revealing interview with David Letterman on Wednesday. In vivid detail, the actress told Letterman that after days of stomach pain, she went to the emergency room to figure out what was wrong, only to find out that she actually had gas.

"My publicist was just telling me that the last story that's out is that I went to the hospital because I had gas. Which, I was like, 'I'd like to confirm them. I think we should,'" she told MTV News. "I had my first fart in the hospital!"

But it seems the story may be a little more serious than that. On The Late Show With David Letterman, Lawrence told the talk show host that her pain was so severe that she thought she had an ulcer. When she did finally go to the hospital, doctors performed an endoscopy, which allows doctors to view one’s stomach, esophagus, and part of the duodenum by using a tiny camera attached to a long tube, according to Mayo Clinic. It is usually performed to help diagnose digestive problems.

"I thought I had an ulcer, but it turns out it was a 'fulcer,'" she joked. "I went to the emergency room … I just did this thing yesterday called an endoscopo-something, where they put you to sleep.”

As part of the procedure, Lawrence was put to sleep and the 23-year-old said she had some pretty bizarre dreams while she was under — including one where she was paralyzed and another where she was in the midst of a nuclear explosion.

"I dreamed there was a nuclear bomb that went off,” she said. “And the first lucid conversation I remember having was about the Kardashians!"

She’s fine now, as she continues her media rounds for the upcoming Hunger Games sequel. Watch video of the candid interview below: