Yes, many people have stomach issues if they have autoimmune diseases and pain. There are a lot of medication’s that we take that can affect our stomach by either creating too much acid or irritating the lining, especially things that are anti-inflammatory like naproxen, aspirin, and Aleve. Those are not the only reasons that some of us have stomach issues issues. It may be true that the majority of people that have autoimmune diseases are more likely to have other things from the auto immune list myself I have also been diagnosed with Crohn’s which is a horrible disease. I can take the pain from my spondylitis, inflammatory arthritis and psoriasis. Arthritis better than I can deal with the issues issues of crown caused by Crohn’s disease .