Most people expect joint pain and lower back pain from ankylosing spondylitis (AS), but symptoms like bloating may come as an unwelcome surprise.

Although AS causes joint damage in the neck, spine, and hips, it can affect other parts of the body as well. With more than 1,000 MySpondylitisTeam members reporting gastrointestinal (GI) symptoms, GI issues like bloating appear to be common among people with AS.

If you have frequent bloating with AS, discuss your symptoms with your health care providers to be sure that you’re managing the symptom as well as possible.

Can Ankylosing Spondylitis Cause Stomach Bloating?

You might wonder if your bloating has anything to do with your ankylosing spondylitis. Although a connection between AS and GI symptoms such as bloating isn’t well understood, some evidence suggests that inflammation associated with AS can affect the gut.

Ankylosing Spondylitis and the Gut

Researchers have found that people with autoimmune disorders such as rheumatoid arthritis, psoriasis, and AS have imbalances in their gut microbiome — the naturally occurring bacteria that support intestinal health and immunity. When the gut microbiome isn’t healthy, damage to the intestine can cause bacteria and toxins to leak into the bloodstream in a condition known as leaky gut. Leaky gut has been linked to autoimmunity, in which the immune system mistakenly attacks healthy cells and tissues in the body.

In people with AS, gut dysbiosis — imbalanced gut bacteria — has been shown to cause abnormally low levels of gut bacteria and a lack of bacteria diversity. Rheumatology researchers are still trying to determine whether gut dysbiosis in people with AS may be due to inflammation from AS or if gut dysbiosis may cause AS to develop.

Common ankylosing spondylitis GI symptoms include:

• Bloating
• Flatulence (gassiness)
• Diarrhea or constipation
• Abdominal pain
• Bloody stool (poop)

Research has shown that as many as 60 percent of people with AS have signs of microscopic gut inflammation without any GI symptoms.

Irritable Bowel Syndrome

People with ankylosing spondylitis are about 2.5 times more likely to develop irritable bowel syndrome (IBS) compared to the general population. IBS can cause painful bloating and changes in bowel movements. It’s treated with a combination of dietary changes, medications that help regulate bowel movements, painkillers, and antidepressants.

Inflammatory Bowel Disease

In some cases, bloating may be a sign of inflammatory bowel disease (IBD), an autoimmune disease that can be linked to AS. IBD, which includes Crohn’s disease and ulcerative colitis, causes inflammation in the digestive tract and can lead to intestinal damage. Because IBD is part of the classification criteria for axial spondyloarthritis (axSpA), it can help doctors in diagnosing AS when present.

“Wondering if anyone has ankylosing spondylitis that’s related to Crohn’s. I’ve had Crohn’s for seven years and was diagnosed with AS last summer,” a MySpondylitisTeam member wrote.

Between 5 percent and 10 percent of people with AS develop IBD, according to Cleveland Clinic, and approximately 20 percent of people with IBD develop AS. If you have persistent GI tract symptoms, your rheumatologist (joint specialist) can refer you to a gastroenterologist (digestive system specialist). They can perform blood and imaging tests (e.g., computer tomography or colonoscopy) to see if you have IBD, and if so, which one. For people with AS and IBD, it’s crucial for their rheumatologist and gastroenterologist to work together on a treatment plan. Some medications that are effective for managing AS might not help IBD — and could even worsen its symptoms. Close coordination ensures both conditions are treated safely and effectively.

“I too have Crohn’s! It’s interesting how so many different autoimmune diseases are linked together,” said another MySpondylitisTeam member.

One member shared their frustration with managing both IBD and AS: “I’m 75, but I have had problems with back, hip, neck, and shoulder pain, as well as GI problems, including ulcerative colitis for years.”

Depending on the severity of either condition and the level of disease activity, AS with IBD is typically managed with:

• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen — These can sometimes aggravate IBD symptoms, so they’re used cautiously.
• Biologic drugs such as tumor necrosis factor (TNF) inhibitors — Some biologic drugs work for both conditions, but some, such as interleukin (IL)-17 inhibitors, may help with AS symptoms but worsen IBD symptoms.
• Disease-modifying antirheumatic drugs (DMARDs) — These treatments help slow joint damage in AS, though they are less commonly used for IBD.
• Lifestyle changes — These may include regular exercise, stress management, and dietary adjustments to support gut health and reduce inflammation.

Both AS and IBD treatment options are aimed at managing symptoms and reducing disease activity to prevent tissue damage in the musculoskeletal system with AS or the gastrointestinal tract with IBD.

A Side Effect of Medications

Bloating may be a side effect of some drugs used to treat AS. Ongoing use of NSAIDs for chronic pain in AS can cause stomach upset and irritation, which may feel like bloating. If an NSAID you’re taking causes bloating, your doctor may recommend a change to your NSAID or suggest adding an antacid or another medication to protect your stomach lining.

Bloating can also be a side effect of sulfasalazine (Azulfidine), a DMARD that’s sometimes used to treat AS. It’s good to discuss potential side effects in detail with your doctor before starting a new medication. If a side effect such as bloating becomes intolerable, you can ask them about other treatment options.

What Does Bloating With Spondylitis Feel Like?

MySpondylitisTeam members describe their experiences with bloating and other GI issues, like ankylosing spondylitis stomach pain.

“My stomach is very bloated and I look pregnant,” said one MySpondylitisTeam member. “Don’t know what that is about. I seem to be having lots of intestinal issues, gas, and bloat.”

Another member shared, “I am having stomach problems — bloating, gas, and constipation. I lost about 65 pounds this past year and it feels like my clothes are tight from being bloated.”

Members have also shared tips for what helps with bloating and gas, including dietary strategies. One said, “I quit bloating when I don’t eat wheat and eat more green veggies.” Another added, “You might find the most help from consulting a nutritionist to help you understand and fine-tune your diet based on your particular circumstances.”

An important fact to remember is that people with ankylosing spondylitis may have a swollen-looking abdomen, even if they don’t have a stomach problem. This can happen because changes in the thoracic cage (spine and chest) due to kyphosis — a forward curving of the spine — can make the abdomen look more distended (pushed outward), mimicking the appearance of bloating.

Lifestyle Changes To Manage Bloating With Ankylosing Spondylitis

If you experience bloating with AS, there are steps you can take to improve your physical and psychological well-being and boost your quality of life. Here are some ways to help relieve symptoms of bloating and improve your overall health.

Stay Physically Active

Regular exercise is typically an aspect of treating AS to promote good posture, balance, strength, and flexibility. Exercise and physical activity can also help some people reduce GI symptoms such as bloating.

“I’ve seen videos online for chair exercises,” one MySpondylitisTeam member wrote. “I feel worse when I’m not moving.”

Staying active can help reduce inflammation in the gut and improve immune function. Exercise and simple activities such as taking a walk, using stairs, or gardening can help decrease gastrointestinal symptoms. Exercise can also help improve cardiovascular health and weight management, and it may improve the effectiveness of medications.

Your doctor can give you a referral for physical therapy. A physical therapist can help you with movement and exercises that are right for your particular condition.

Drink Plenty of Water

Drinking water and staying hydrated are essential factors for maintaining diverse gut bacteria, good digestion, and intestinal health. Our cells depend on water for proper functioning. Drinking between six and eight glasses of water per day is associated with better health in general.

Maintain a Balanced Diet

Many health professionals recommend an anti-inflammatory diet, particularly for people living with chronic illnesses such as AS or IBD. An anti-inflammatory diet emphasizes nutrition-rich foods such as whole grains, fruits and vegetables, beans, fish high in omega-3 fatty acids, and healthy fats such as those found in olive oil and avocados.

Avoid foods that are associated with inflammation, such as:

• Refined sugars, sweets, and sugary drinks
• Refined carbohydrates, such as white rice and white flour bread, pastas, and pastries
• Fried foods
• Red meat and processed meats, such as sausage and hot dogs
• Saturated fats, such as lard and margarine

If you have IBD, you may need to make adjustments to your diet during flare-ups. Always ask for medical advice if you are experiencing acute gastrointestinal symptoms.

Talk to Your Doctor

Talk to a health care provider about your current AS treatment plan and how it might affect your GI system. Your doctor might make changes or recommend medications specifically for ankylosing spondylitis GI symptoms. If you have AS and IBD together, for example, your health care provider might prescribe specific medications to address widespread inflammation or reduce immune system activity.

Find Your Team

On MySpondylitisTeam, the social network for people with spondylitis and their loved ones, more than 98,000 members come together to ask questions, give advice, and share their stories with others who understand life with spondylitis.

Do you have ankylosing spondylitis and bloating? How do you manage your gastrointestinal symptoms? Share your experience in the comments below, or start a conversation by posting on your Activities page.