Telling people the news
I am inclined right now not to tell anyone much. My immediate family knows; my boss knows, and HR knows since I'm using sick time to supplement my contract hours to allow me to got 1/4 time this semester(I teach at a University).
I haven't told many beyond that, since I don't have any outward symptoms (though I've lost weight and a few people have noticed—maybe the loss is due to this, but certainly because of an IBS dx this year, inability to find things to eat that don't bloat me, and worry—I can't eat when I'm anxious).
My inclination is to keep it to myself. It's isolating but more isolating when you tell people and they look at you with sympathy (and some with fear) from that point on.
I watched the Michael J. Fox documentary a few weeks ago, "Still". He said he didn't tell people about his dx for years. He was able to hide his symptoms, and he said "if he didn't tell anyone, then it wasn't real". I'm inclined to agree with him right now.