Research suggests that there is a link between psoriatic arthritis (PsA) and inflammatory bowel disease (IBD), which both involve inflammation. However, a person with PsA may experience symptoms related to the GI tract without developing IBD.

PsA is a form of inflammatory arthritis that affects the joints. It develops in about 30% of people with psoriasis and can cause symptoms such as loss of range of motion, stiffness, swelling, fatigue, and more.

IBD is the term for a group of conditions, including Crohn’s disease and ulcerative colitis. Chronic inflammation in the gastrointestinal (GI) tract causes IBD. The symptoms can include diarrhea, bloody stools, abdominal pain, and fatigue.

This article discusses what researchers know about PsA and bowel problems.

Research shows that PsA shares a connection with several GI tract issues, including IBD.

Review articles from 2016 and 2017 have also found a link between psoriasis and IBD. The included research showed that people with psoriasis are more likely than other people to receive a diagnosis of IBD.

In a 2017 study, researchers found a link between PsA and an increased risk of Crohn’s disease. However, the findings revealed no increased risk of ulcerative colitis.

Growing evidence also suggests a link between PsA and the gut microbiome, which refers to the microorganisms that live in the human digestive tract.

Anyone who has PsA and develops symptoms in their bowels should let their doctor know so that they can test for the presence of IBD.

People with both psoriasis and IBD may benefit from certain treatments that doctors use for both conditions. These treatments include:

PsA inflammation can affect several areas of the body, including the organs and other tissue.

Skin and nails

Approximately 68% of people who develop PsA already have skin symptoms due to psoriasis. However, in about 15% of cases, a person will develop symptoms of PsA and psoriasis at the same time.

About 80–90% of people living with PsA will also experience nail pitting or other nail symptoms.


Uveitis is a rare inflammatory disease that affects a person’s eyes and eyesight. It occurs in about 7–20% of people living with psoriasis. Treating uveitis is important to prevent vision loss.

Other possible eye-related complications include conjunctivitis, blepharitis, and scleritis, among other inflammatory conditions.


In a 2015 review, researchers found a link between PsA and the development of chronic obstructive pulmonary disease (COPD). COPD causes an inflammatory response in the lungs, which can make breathing more labored and painful. Due to this association, people living with PsA should take particular care to avoid smoking and exposure to secondhand smoke.


Research indicates that a person living with PsA has a higher risk of developing cardiovascular disease. In this case, the chronic inflammation associated with PsA damages the blood vessels. This damage can lead to the hardening or thickening of the vessels, which can increase a person’s risk of stroke or heart attack.

It can be difficult to predict which symptoms will be the most stressful or painful for someone living with PsA, as the severity of the symptoms can vary among individuals.

According to the National Psoriasis Foundation, some common symptoms of PsA include:

  • tender, painful, or swollen tendons
  • fatigue
  • reduced range of motion
  • nail pitting or separation
  • swelling in the toes and fingers
  • joint swelling, stiffness, pain, throbbing, or tenderness
  • stiffness in the morning
  • pain or redness in the eyes

The severity of psoriasis does not directly affect the severity of PsA. In other words, a person may find that their PsA symptoms are mild compared with their psoriasis symptoms or vice versa.

Diarrhea is not among the common symptoms of PsA. However, it is a common symptom of IBD.

A person with PsA who develops severe or recurring diarrhea should talk with their doctor about their symptoms. Testing can help identify or eliminate the presence of Crohn’s disease or ulcerative colitis.

PsA shares a link with IBD, as both conditions involve chronic inflammation, which can affect several parts of the body.

Anyone with PsA who develops diarrhea or other IBD symptoms should talk with their doctor. They should also let their doctor know if they develop additional symptoms in their eyes, skin, or other parts of the body. Treating PsA can help prevent complications and disease progression.