Psoriatic arthritis (PsA) is a chronic inflammatory condition that can lead to swelling, stiffness, and pain in the joints. Most people with PsA also have psoriasis, which typically causes red and white scaly patches to appear on the skin and scalp.

Experts have linked psoriatic arthritis to other inflammatory conditions, such as inflammatory bowel disease (IBD). Keep reading to learn more about the link between psoriatic arthritis and digestive issues and how to treat both conditions.

a woman holding her stomach because she has digestive issues caused by psoriatic arthritisShare on Pinterest
A person with PsA may experience other inflammatory conditions, such as IBD.

A healthy immune system attacks harmful viruses, fungi, and bacteria. Both psoriatic arthritis and IBD involve an abnormal immune system response, in which the immune system attacks healthy tissue. Chronic inflammation damages the joints in PsA and the digestive tract in IBD.

Research suggests that there is a link between PsA and common forms of IBD, including Crohn’s disease and ulcerative colitis. A 2016 review of studies and a 2017 study found that people with psoriasis — about 30% of whom have PsA — were more likely than other people to receive a diagnosis of IBD.

However, a 2018 review linked PsA to Crohn’s disease but not ulcerative colitis.

Studies point to genetic similarities and shared inflammation pathways in PsA and IBD, especially Crohn’s disease. Some research also suggests that people with these conditions have lower levels of beneficial bacteria in their body.

Due to the overlap between IBD and PsA, researchers have concluded that people who have these conditions can benefit from similar treatments.

People with psoriatic arthritis sometimes develop digestive issues relating to IBD, which includes Crohn’s disease and ulcerative colitis.

The digestive tract runs from the mouth to the anus, and Crohn’s disease can affect any part of it. Ulcerative colitis affects the lining of the large intestine, known as the colon. Its hallmark is the development of small sores or ulcers in the bowel.

The most common IBD symptoms include:

  • diarrhea
  • bloody stools
  • pain or cramps in the abdomen
  • appetite loss
  • unintended weight loss
  • fatigue or lack of energy

It is possible to experience any combination of these symptoms, which may be mild or severe. Anyone who is experiencing IBD symptoms should talk to a doctor. IBD can lead to serious complications that require medical attention, including:

  • inflammation in adjacent parts of the intestines, leading to the formation of a fistula
  • tears in the anus, known as fissures
  • narrowing of the intestines, called a stricture, due to inflammation
  • severe dehydration
  • severe bleeding or other issues in the colon that require surgery

The goal of treating people with psoriatic arthritis and IBD is to reduce the severity of the symptoms and the frequency of disease flare-ups to improve quality of life. Several drugs can treat both IBD and PsA. These include:

  • Biologics: Some research suggests that the biologic drugs infliximab and adalimumab are effective treatments for both IBD and PsA. Biologics are targeted medications that lower inflammation in the body. However, not everyone responds to them.
  • Janus kinase (JAK) inhibitors: Research indicates that JAK inhibitors, such as the oral nonbiologic disease-modifying antirheumatic drug (DMARD) tofacitinib, are an effective alternative to treat both IBD and PsA.
  • Immunomodulators: Doctors sometimes use cyclosporine and tacrolimus to treat IBD, as well as PsA. These medications suppress the immune system to reduce inflammation.
  • Corticosteroids: The short-term use of drugs such as prednisone can treat IBD and PsA flare-ups. These drugs reduce inflammation by suppressing the immune system.

Sometimes, if other treatments do not improve IBD symptoms, surgery may be necessary.

Ibuprofen and naproxen are over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) that people often take to reduce inflammation in PsA. However, doctors may recommend that people with IBD avoid these medications, as they can worsen IBD symptoms.

Some of the symptoms of IBD are treatable with acetaminophen, antidiarrheal medications, and anti-gas medications. A person should talk to a doctor before taking any medication or supplement, though.

A person’s diet can affect their IBD symptoms. Doctors may recommend dietary changes, such as avoiding greasy or spicy foods and carbonated or caffeinated beverages.

Stress can aggravate both IBD and PsA. If this is the case, exercise and counseling may help relieve the symptoms by reducing stress.

Many people with psoriatic arthritis also have IBD. Both of these chronic diseases involve inflammation. The symptoms of IBD may include diarrhea, bloody stool, and pain in the abdomen.

It is important for people with psoriatic arthritis to discuss any digestive issues with their doctor. Several medications can treat both psoriatic arthritis and IBD.