I am a veteran ileostomate of three years. TRUST ME we all worry about that. There is an article I found on Google written by a stoma nurse who said immediate hospitalization with IV's and anti-nausea drugs via IV are COMPLETELY and IMMEDIATELY necessary for ileostomates with the Noro Virus. My own surgeon and ostomy nurse concur. This is a life threatening situation for us ileostomates so it sounds like your hospital did a good job for you. I think you will be fine and not get this again, because the body builds antibodies to this that last awhile, so while your family now has it, I think you are likely immune.
I had a life threatening gut injury in 2006 (during what ended up to be an unneeded pelvic surgery, long story) but I cruise a lot and am actually out to sea right now. I have heard of a few cases on board so I am avoiding crowds as much as possible, washing hands frequently, and doing what can be done. Other than that I'm just praying.
So, you are not alone with your concerns. It's the season for this and as spring comes the chances of getting this wane.
Good luck. Rosemary