Hi, well it depends. Do you care what they 'think', in attempting to increase their knowledge, or validation..possible all?
It is pretty much indescribable at times, unpredictable and symptoms can be so different day to day. I would think it would be exhausting and I feel it would be a waste of time to have to try and convince someone you feel unwell. The energy is better spent in caring for your own well being. Sorry if this sounds insensitive. Those who know you best will understand.
If you want to increase their knowledge, point them to some literature on Crohn's. There is a vast amount out there.
Comments from friends, and family can happen. Many hear silly things, like well you should, shouldn't, my friend said, a sister of a cousin of a friend is fine and has it...blah, blah...It can be endless. The best thing i have found is to educate yourself to the best of your ability, and if they really care they will to.
Be well, God Bless.