My brother has Crohns. There is a possibility especially if you have a relative. Go and see a doctor, as it could be something else. I get a similar reaction around menstruation as well. That is normal. It is between periods that it should not happen. Also, my brother has had a huge success with natural therapies and a strict exercise routine. He is off all drugs, as some are quite toxic that can be give (always read the contraindications in the medication packet as some drs don't tell you, as was my brother's case). He finds that meditation dailly , smaller more frequent meals. He sees a naturopath and a chiropractor, and is the healthiest he has been in years. His mood swings are still eratic though. Good luck.