Research suggests 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 some 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 issues.

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Research from 2021 shows that PsA shares a connection with several GI tract issues, including 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 microorganisms in the digestive tract.

Anyone who has PsA and develops symptoms in their bowels should inform a doctor so 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 tissues.

Skin and nails

Approximately 68% of people who develop PsA already have skin symptoms due to psoriasis. However, in around 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 an uncommon 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.


According to the Arthritis Foundation, the inflammation that PsA causes can lead to a condition called interstitial lung disease. This can cause shortness of breath, fatigue, and coughing.

A 2021 paper also states that those with PsA have an increased risk of developing other conditions that affect the lungs, such as chronic obstructive pulmonary disease (COPD). Symptoms include:

  • frequent wheezing or coughing
  • shortness of breath
  • difficulty taking a deep breath
  • excess phlegm


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.

Can psoriatic arthritis affect your intestines?

PsA can affect the intestines. The inflammation associated with PsA can occur in different parts of the body, including the intestines, which increases the risk of developing IBD.

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 their PsA symptoms are mild compared with their psoriasis symptoms or vice versa.

An individual may note a correlation between PsA flares and the severity of their skin or joint symptoms.

Diarrhea is not among the common symptoms of PsA. However, it is a frequent 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 seek medical advice. They can also inform a doctor if they develop additional symptoms in their eyes, skin, or other parts of the body. Treating PsA can help prevent complications and disease progression.