I believe that cannabis relaxes the LES(lower esophageal sphincter ) and that can sometimes trigger GERD/reflux . It is very good for pain as we all know and has a lot of positive effects on the digestive tract, reduces nasea, relaxes the muscles(the stomach is a muscular organ after all), and more.
For me, I have to be careful not to vape too soon after a heavy meal, or first thing in the morning, these upset my stomach. But everybody is different. Like with food, you may need to adjust your herb consuming routine. The foods you eat are super important. If you are not eating right then just about everything else can go right out the window.
Different herbs and spices can aid in digestion as well, a quick search should give you a nice hearty list of herbs that are known to be a digestive aid, soothe the stomach and digestive system. Cilantro is one for example that everyone should know about and probably has in their kitchen cupboard. I suggest as much organic , FRESH food as possible, avoid processed things.
Do be aware of food allergies as well. There are dairy allergies, gluten(wheat) allergies, even a milk protein allergy(different then being lactose intolerance), and tons of other things that may upset one. Generally, if something upsets your digestion, or just does not affect your body well overall, you should avoid it. some things that arent bad simply need to be started slowly if they cause irritation at first , gradually working ones way up to consume more.
I have also found when I make edibles(fresh or ABV, but i dont often use fresh herb for cooking) that I must strain all the plant matter. The last time I tried eating straight ABV(that HAD been ground fine once more before consuming) mixed in with some food that normally never upsets me, i was in bed for two days. Just making an example of this. Keep in mind everything you put in or on your body, sometimes even from very little amount, can make changes to your bodies functions.
i can not give medical advice, but i am simply sharing some of my own experiences and personal knowledge and opinions. I deal with GERD and indigestion on a regular basis and thought I could contribute to this thread.
remember, health is wealth. we are nothing without it.