Should One Get Tested For A Gluten Allergy, Given The Left-side Abdominal Pain, Gas, And Long-term Use Of Beer And Nicorette Mints?

friend having gas burping pain in left side she drinks 8 beers a night and uses Nicorette mints for 9 a day for 3 years. She eats salads and it seems to make it worse. She has never been tested for gluten allergy and wants to know if she should change diet or get tests they are all out of pocket so wants advise