Btw, my daughter is the kind of person who refused to take Tylenol, even in high school, and even if she had a truly evil headache. However, in college, she hurt her knee and the doc prescribed a high dose of ibuprofen. She took it for only one or two days and not long after, she landed in the ER with her first-ever full-on flare.
I don't think it caused her Crohn's, but am sure it helped to serve as a tipping point for exacerbating the condition.