Crohn’s is usually thought of as a gut problem—and technically, it is. The bowel disease can cause inflammation anywhere along the digestive tract, from the mouth to the anus, impacting all layers of the intestinal wall. This can lead to health issues like abdominal pain, rectal bleeding, and bowel urgency, and those are the symptoms that often motivate people to see a GI doctor. But up to roughly 40% of people with an inflammatory bowel disease (IBD) experience symptoms outside of the gut, according to the Crohn’s & Colitis Foundation. These extraintestinal manifestations, as they’re called, sometimes show up months or even years before someone hears the words “You have Crohn’s disease.”
So while the gut tends to get all the attention when Crohn’s comes up, the disease is actually an immune system issue that can trigger inflammation throughout the body. “It gets filed under ‘GI’ because that’s where it announces itself and where we look at it, but the underlying problem is a dysregulated immune system,” says Vikas Taneja, MD, a board-certified gastroenterologist at Hackensack Meridian Health’s Jersey Shore University Medical Center. As a result Crohn’s can affect everything from the joints and skin to the liver and bones.
That brings us to these six lesser-known symptoms of Crohn’s disease. On their own they may seem disparate; when occurring together or in combination with GI distress, they can point to an immune system issue and are worth mentioning to your doctor.
1. Achy joints and muscle or tendon pain
Feeling stiff and achy may not seem like a symptom of Crohn’s. However, joint inflammation, also known as arthritis, is among the most common manifestations of IBD outside of the digestive tract, according to the Crohn’s & Colitis Foundation.
Fahad Khan, MD, a board-certified gastroenterologist at Hackensack University Medical Center, says he sees this firsthand quite often. “In my practice the most common extraintestinal symptom in Crohn’s is peripheral arthritis,” he says. Studies suggest that peripheral arthritis—which typically affects the hands, wrists, elbows, knees, and feet—impacts 10% to 20% of people with Crohn’s disease. Similarly, axial spondyloarthritis (axSpA), a chronic inflammatory arthritis that largely affects the spine, pelvis, and sacroiliac joints, occurs in about 5% to 15% of patients with Crohn’s.
Muscles, ligaments, and tendons can also be affected. A type of inflammation called enthesitis, which occurs where tendons and ligaments connect to bones, affects up to 50% of IBD patients, according to a 2024 study. Achilles tendonitis and plantar fasciitis are two common examples of enthesitis, and both can limit mobility.
These sorts of aches and pains alone don’t point to a Crohn’s disease diagnosis, but if they occur alongside other major symptoms of Crohn’s disease, such as diarrhea, mouth sores, unexplained weight loss, and other types of GI distress, definitely talk to a doctor.
2. Eye inflammation
Red eyes, blurred vision, light sensitivity, and spots that drift into your vision (a.k.a. floaters) can also signal Crohn’s disease. The culprit may be a condition called uveitis, which is inflammation of the middle layer of the eye, known as the uvea. It is among the most common ocular complications of Crohn’s and is estimated to impact roughly 11% of people with the disease, according to a 2024 study.
If you notice you tend to experience vision issues or eye pain and GI flare-ups, it can be an indicator of systemic inflammation—and a sign that it’s time to see a doctor.
3. Skin issues
Crohn’s can show up on your skin too. One of the most prevalent skin manifestations is erythema nodosum, which affects about 4% to 15% of people with Crohn’s. It’s an inflammatory disorder that affects the fat just below the skin’s surface and causes tender, red bumps to form. They’re most often on the shins, and over time the bumps may turn purplish.
Other skin problems that could signal Crohn’s include painful pus-filled ulcers tied to pyoderma gangrenosum, as well as hidradenitis suppurativa (HS), which causes painful bumps that look like pimples or boils but over time can develop into larger lumps called abscesses. HS generally forms in areas where skin rubs together, including the armpits, groin, inner thigh, or around the genital or anal area. Both conditions are believed to be linked to immune dysregulation, which may help explain why they are found in people with Crohn’s.
If you suspect you have any of these skin concerns, see a dermatologist and be sure to mention any GI symptoms as well. They might be able to help determine whether Crohn’s is at play.
4. Gallstones
Dealt with gallstones in the past? Well, that, too, can be a sign of Crohn’s. People with the disease are roughly twice as likely to have gallstones as the general population, with the overall prevalence among Crohn’s patients ranging from 13% to 15%. Many cases of gallstones are asymptomatic, and even when accompanied by symptoms, gallstones are frequently confused with other conditions, like heartburn or IBS, which can make them difficult to link with Crohn’s.
5. Kidney stones
People often attribute kidney stones to diet and lifestyle factors rather than underlying Crohn’s disease. But they can sometimes signal deeper, systemic inflammation stemming from the GI tract. At diagnosis people with Crohn’s disease are roughly 2.8 times more likely to have had kidney stones in the past than the general population, according to a 2021 study. And while not all people with kidney stones have symptoms, these deposits can be incredibly painful if they grow or dislodge. Like other lesser-known symptoms of Crohn’s, developing kidney stones is far from confirmation that you have the IBD. Still, when they occur with other potentially related symptoms, it’s worth investigating further.
6. Weak bones
Frequent fractures or surprisingly bad bone density on a DEXA scan? The inflammation associated with Crohn’s can quietly impact the absorption of bone-building nutrients such as vitamin D, vitamin K, and phosphorus. Alongside systemic inflammation, this can accelerate bone loss, leading to conditions like osteopenia (low bone density) and osteoporosis (fragile bones). Studies show that as many as 18% to 42% of people with IBD have osteoporosis, while 22% to 77% have osteopenia.
Getting a Crohn’s diagnosis
On the surface Crohn’s disease seems like a GI condition. But it’s much more than that. From joints and skin to the liver and bones, far more than the gut can fall victim to the inflammation associated with the condition. In fact having symptoms in other parts of the body is fairly common. “Up to half of patients with Crohn’s will develop extraintestinal symptoms over the disease course,” Dr. Khan says.
None of these symptoms on their own necessarily mean you have Crohn’s disease. However, if you’re experiencing some of them, especially alongside GI symptoms, it’s worth mentioning to your doctor so they have the full picture. That context may help your provider determine whether further evaluation, including a GI referral or additional testing, makes sense.