A friend's sister took a few ibuprofen a few days ago on an empty stomach, started throwing up blood for several hours, spent the night in the ER. Now she has an ulcer.
Edit: Ulcer, not hernia.
Edit: Ulcer, not hernia.
I say this mostly because it is common (though not recommended) to take them on an empty stomach and it seems her reaction to the single pill does was extreme.
However, even when changed to an ulcer, it is the kind of anecdotal evidence that keeps urban legends alive. Long term use of ibuprofen is known to cause ulcers. Rare use, on an empty stomach or not, does not instantly cause bleeding and ulcers. It is much more likely that Broken_Hippo is right or that she indeed has been chronically using ibuprofen.