I started Server Check.in, a simple website and server uptime monitoring service, almost four years ago. I built it when I was in the hospital and recovering from mono (symptoms were worse because of one of the Crohn's-related drugs I was taking), and it's been a very slowly-but-steadily growing service since.
I wrote a four-year retrospective post on the service, and published it on the Server Check.in blog: Four years running Server Check.in.
It's one of the many side projects I run under the umbrella of Midwestern Mac, LLC, and it's nice to be able to look back and see all the progress I've made, where the work has taken me (e.g. publishing a book on Ansible!)... and to realize that I was finally able to finish that retrospective post because of some free time afforded by another Crohn's-related hospitalization—this time due to surgery.
So Crohn's is good for progress in building and expanding Server Check.in, at least :)