The caffeine in soda can also increase stomach acid production, worsen episodes of diarrhea, and contribute to constipation. (ksl.com)
This includes increased stomach acid levels requiring acid inhibitors and moderate to severe gastric inflammation with possible stomach lining erosion. (westonaprice.org)
You can help stimulate increased stomach acid by drinking one or two tablespoons of apple cider vinegar before meals. (immortalitea.com)