Every one has had to deal with stomach upset of one kind or another. You could say that it comes from eating fatty foods, products that contain too much salt or sugar and even spicy foods that linger in our digestive tracts. But that would probably be the basic cause while other possibilities go unrecognized.
You might be a person with a slow metabolism and so the food remains with you longer. You could have an intolerance to certain products or products in combination. As a highly stressed individual, you would surely have a reaction that matches the physical tensions you sense.
Many things go towards distressing your digestive tract and prohibiting the proper absorption of what we eat. So what can you do about it? It depends on the actual problem area, your own sensitivity, your physical condition and other factors that are particular to an individual.
I for one had a lot of acid that wanted to resurface in my throat. So I started looking at what I could do for that. I raised the head of my bead to keep my head above the rest of my body. I stopped eating and drinking 3 hours before I went to bed. The last thing I had was a tall glass of water with two teaspoons of apple cider vinegar in it.
In the morning, I drank a tall glass of warm water with a slice of lemon squeezed into it. Then I waited for at least 20 minutes before eating anything and ate my breakfast in a relaxed state. Before eating that meal, I took my usual multi vitamin, two vitamin D tablets and Acedophylus, a pro-biotic. Every other morning I had yogurt with active probiotics in it for that meal too.
My lunch became my main meal to keep the heavier meal to a time where I could work it off. I preceded that meal with a digestive enzyme tablet and ate my meal being sure to chew everything as much as possible.
Believe it or not, this worked and I do not get any stomach issues. I am a firm believer in pro-biotics. As to the other techniques I used, I came across these and tried them one at a time till I found a regime that worked for me. If your problems are similar, try the pro-biotics first and expand from there.