I'm taking a new anti-inflammatory (relafen (nabumetone) 4 days). if it makes my gut hurt is it better to switch again or take something like prilosec with it?

Not unusual: If you are having stomach pain after just 4 days, you need to stop this anti-inflammatory med immediately. You need to see a dr. And find out if a a ppi like Prilosec or Nexium (esomeprazole) would be indicated. You could be developing an ulcer. Switching to a different med of this type will not be beneficial and probably will be very detrimental.