If it’s a stomach virus then hydration and rest, Pedialyte if you’re dehydrated, trying not to eat until your stomach can handle it (ie waiting it out)

Zofran for nausea and puking (docs will usually prescribe if you explain you have noro). Cannabis for nausea and appetite.

I’m no expert - not even smart - but if it were me, I would:

Avoid all fruits, dairy, and high fiber foods. No Vitamin C tablets. .

Stick with rice, just plain white rice plus sips of Gatorade or Pedialyte to prevent dehydration, until you see improvement. Not too much liquid. Liquids are necessary for hydration but they can also trigger diarrhea and diarrhea is one cause of dehydration.

Then, once things are improving, try adding some chicken broth into the rice. Then wait. Next, try a small amount of jello to test. Then wait. If ok, then more jello. Then wait. If things are ok, add cheese a small amount at first. Then wait a bit.

If things are improving, try bread, potatoes, and other easy on the tummy, mild foods.

(No BRAT diet, the apples can cause loose stools.)

Hope this helps you.

Hygiene.

Wash everything. Sanitize everything. No phones in the bathroom. The problem with noro is, yeah it clears up in 48, but there's no immunity so if you get a tiny bit of yesterday's poo in your mouth, oops! Restart the clock.

This is also why households with tiny children have it real bad right now. I'm sorry.