snacks recommendations?

I've had gastritis for a few months and i have yet to find a snack i can buy that i can eat in between meals or when i feel acid reflux. I saw people recommending pretzels but i tried them once a while back and i think they gave me diarrhea, the same with plain biscuits, i tried goldfish pretzels and that went the same way, i suppose because of the seasoning on top (thats my bad). I also saw people recommending ricecakes but i am scared of eating anything from the store since it hasn't gone well in the past. Is it just because I ate too many and for too many days or weeks in a row? idk what to think anymore Please help. Im aware that I can make toast but if there is a thing i could buy and have at all times on me that would be great.