Hello!

Thank you for the query.

As panic attacks can produce any kind of symptoms, it is very hard to tell if it is only anxiety or some other disease as well. Definitely anxiety can give abdominal pain including cramps, nausea, vomiting, diarrhea, chest pain, shortness of breath, acid reflux, headaches, shivers, muscle spasm (what can lead to muscle pain) and many many more. However before anxiety diagnose, all other reasons of such symptoms should be ruled out.
It is advisable to have fool blood work with pancreas and liver tests, thyroid tests, ions levels (including magnesium and calcium), urine tests, stool tests, abdominal ultrasound. If stomach aches are present in upper middle abdomen, upper GI endoscopy should be performed as well. If there is a blood or mucus in stool, colonoscopy should be performed as well. Heart condition with ECG should be checked as well.
If all this tests will came negative you can be diagnosed with anxiety.
If you suffer from stomach aches and diarrhea or constipation you may also suffer from IBS (irritated bowel syndrome). In some cases IBS can be a reason of anxiety. There is very hard to divide this two diseases so both should be treated together.
Nowadays, we have good anxiety controlling medicines (like Sertaline, Alprasolam) and IBS remedies (Mebeverine, Rifaximine). You may find psychiatrist consultation very helpful.

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

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