Crystals for Health
 

What would you think is a good combo for crystals for health? Specifically gastro problems.

Internet says citrine, carnelian, and amethyst but is there something else to help add to it?

Depends on the cause of the gastro problems but peridot can help with stomach pain from ulcers and nausea (its good for the flu too!) and boosts your resiliency so you can handle stressful situations. Blue lace agate can remove toxins from the body so if it's more of an infection or food poisoning, if you're struggling with an intolerance.

You can also add clear quartz to amplify the crystals you choose and to bring some clarity, i know personally i feel so scrambled and untethered when my digestive issues flaire up.

Bone broth and chicken stock supercharged with crystals ;)

It depends on the cause of the problems.
I never go by what books or the net says. Not that they're wrong, but your intuition is the best guide you have!
You're Higher Self and intuition know what could help alleviate your specific problem. Books and internet don't, it's more generic.

Personally I'm not a fan of going for citrine, unless this is your own inner choice. Citrine is my favourite crystals, but in many cases I feel yellow calcite is much better suited.
In your case I'd look into that as well, you cannot easily go amiss with it, unless you have a serious dislike when seeing it.

Follow your intuition and again, depends on what the cause it, which isn't necessarily physical but likely emotional.