It’s not common, but some people with rheumatoid arthritis also develop other autoimmune conditions. These include inflammatory bowel disease (IBD), which refers to conditions that involve long-term gut inflammation. Crohn's disease and ulcerative colitis are the most common types people get.
Having RA doesn’t necessarily mean you’re more likely to get IBD. If it does happen, it’s not clear why. Certain genes such as HLA-DRB1 and TYK2 play a role in rheumatoid arthritis and Crohn’s disease. Environmental causes may be important, too.
You may be able to lower your risk for these issues by talking to your doctor about cutting down on non-steroidal anti-inflammatory drugs (NSAIDs) or switching to a different type of medication called COX-2 selective inhibitors, not smoking, and limiting use of glucocorticoids or corticosteroids.
A lot of things can cause issues in your gastrointestinal system.
Some medications: Disease-modifying antirheumatic drugs (DMARDs), corticosteroids, and NSAIDs can all cause side effects that impact your gut and may be uncomfortable. You could have stomach pain, nausea, and diarrhea.
Findings from one study suggest your chances of having reflux and stomach pain are higher if you take 12 milligrams of methotrexate (Otrexup, Rasuvo, Rheumatrex, Trexall) a week vs. 6 milligrams. Talk to your doctor about the possibility of lowering your dose, if yours is high and you have these issues.
Infection: Taking disease-modifying antirheumatic drugs makes it more likely that you can get any type of bacterial infection, including ones that harm your gut. This is because they tone down your immune system, making it less effective at protecting you against things that can make you sick.
Or it might be an autoimmune disease that creates gut issues.
A rarer condition that may develop is rheumatoid vasculitis, which happens when rheumatoid arthritis impacts your blood vessels. It’s a complication of the disease that can occur when you have it for many years and it’s severe. Rheumatoid vasculitis inflames and narrows your blood vessels and can affect your gastrointestinal tract.