Hi, I would say to do you best to let this all go. You are overreacting to this situation.
Can you just send peaceful loving thoughts toward this co-worker. I mean the person is not the niciest person around, but you don't want to get taken over by his/her behavior.
You should be putting energy toward get better health. Crohn's is often caused by heavy metal problems. Do you have a lot of amalgam (so-called silver) fillings? Mercury in the filling can cause crohn's. Most Doctor's don't know much about this. Do some research on this. Put in "Mercury and crohn's" on google. Don't eat mercruy food like large fish (tuna, gropper, ect.). Look into a detox program online. Their are some good book on the subject. The tests for high-mercury are ohten unreliable.
A heavy metals challange is best (a urine test).
Save your energy to more important things. Best wishes. JC