Thanks for posting your query at DoctorSpring.com. I am Dr.R.K and I am pleased to assist you.
I went through your post about Crohn's disease. The symptoms you have mentioned can occur in both Crohn's disease and irritable bowel syndrome.
So it is difficult to say whether it is a flare up of Crohn's disease or just irritable bowel syndrome without doing certain tests.
Fecal calprotectin test may be done. If its level is increased, then the symptoms you have is due to a flare up of Crohn's disease.
Hope this helps, Please feel free to get back with further queries.