Hello!

Thank you for the query.

Upset stomach is very unspecific symptom. It can be present with almost all stomach and abdominal diseases.
However most commonly, such symptoms can appear due to stomach inflammation, peptic ulcers, Helicobacter Pylori infection of the stomach, hiatal hernia. Sometimes such nonspecific symptoms can indicate stomach cancer. That is why you should not neglect it.

Burping can be a symptoms of stomach disease as well.
However burping can be also caused by aerophagia. This is simply increased air swallowing. It can be caused by chewing gum, loose dentures, drinking carbonated drinks, smoking, eating too fast.

I suggest you to visit your doctor and have some tests done. Abdominal ultrasound and blood work should be first. Next should be gastroscopy. During this test, Helicobacter Pylori infection will be checked.

In a meanwhile, you should avoid coffee, soft drinks, and fatty foods.

Hope this will help. Feel free to ask further questions.
Regards.

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