How does IBD affect other parts of the body?

IBD can also cause problems outside the gut. Some people with IBD develop conditions affecting the joints, eyes or skin. These can be known as extraintestinal manifestations (EIMs) and often occur during active disease, but they can develop before any signs of bowel disease or during times of remission. Many of these are not very common.


Inflammation of the joints, often known as arthritis, is a common complication of IBD.

It is most common in those with Crohn’s Colitis (Crohn’s Disease in the colon) and also affects about one out of 10 people with UC.

The inflammation usually affects the large joints of the arms and legs, including the elbows, wrists, knees and ankles. Fluid collects in the joint space, causing painful swelling, although pain may occur without obvious swelling. Symptoms usually improve with treatment of intestinal symptoms, and there is generally no lasting damage to the joints. A few people develop swelling and pain in the smaller joints of the hands or feet. This may be longer lasting and persist even when the IBD is in remission.

Sometimes, the joints in the spine and pelvis become inflamed – a condition called ankylosing spondylitis (or sacroiliitis, in its less severe form). This can flare-up independently of IBD. It often causes pain over the sacroiliac joints, on either side of the lower part of the spine. Stiffness and pain in the spine itself may eventually lead to loss of flexibility.

Symptoms usually improve with treatment for intestinal symptoms and there is generally no lasting damage to the joints. A few people develop swelling and pain in the smaller joints of the hands or feet. This may be longer lasting and may persist even when the IBD is in remission. Drugs and physiotherapy can be helpful in treating these symptoms and the condition is usually managed jointly by rheumatology and gastroenterology specialists.


IBD can also cause skin problems. The most common skin problem is erythema nodosum, which affects about one in seven people with IBD, and is more common in women than men. It consists of raised tender red or violet swellings 1.5 cm in diameter, usually on the legs. This condition tends to occur during flare-ups and generally improves with treatment for IBD.

Another skin condition associated with IBD is Sweet’s Syndrome, where tender red nodules appear on the upper limbs, face and neck, sometimes with a fever. It is generally associated with active IBD, and can be treated by steroids or immunosuppressants.

More rarely, people with IBD may develop a condition known as pyoderma gangrenosum. This starts as small tender blisters, which become painful, deep ulcers. These can occur anywhere on the skin, but most commonly appear on the shins or near stomas. This condition is sometimes, but not always linked to an IBD flare-up. It is often treated by a dermatologist with topical therapy, but may need drug therapy with steroids, immunosuppressants or biological therapy.


About one in 25 people with IBD gets painful sores in the mouth, usually when the condition is more active. These sores can be minor and disappear within a few weeks, but occasionally they can last for many weeks and may require steroid treatment.


Eye problems affect some people with IBD. The most common condition is episcleritis, which affects the layer of tissue covering the sclera, the white outer coating of the eye, making it red, sore and inflamed. Episcleritis tends to flare up at the same time as IBD, and can usually be treated with cold compresses; sometimes steroid drops are prescribed.

The two other eye conditions linked with IBD are scleritis (inflammation of the sclera itself) and uveitis (inflammation of the iris). These conditions are a lot more serious and can lead to loss of vision if not treated. If you get any kind of eye irritation, redness or inflammation, always mention it to your doctor, who may refer you to an eye specialist. Scleritis and uveitis can usually be treated with steroid drops, although sometimes immunosuppressants or biological drugs are needed.


People with IBD are more at risk of developing thinner and weaker bones. Bone loss can be due to the inflammatory process itself, poor absorption of the calcium needed for bone formation, low calcium levels from avoiding dairy foods, or the use of steroid medication or smoking. This can be diagnosed by a dual-energy x-ray absorptiometry (DEXA) scan. Bone thinning can be due to the inflammatory process itself, poor absorption of calcium needed for bone formation, low calcium levels because the diet does not contain enough dairy foods, smoking, low physical activity or the use of steroid medication.

Calcium and vitamin D supplements, stopping smoking, weight-bearing physical activity, avoiding steroids, and, for some people, drug treatment can be helpful. For more details, see Bones and IBD.


People with IBD have an increased risk of developing kidney stones. This can be due to inflammation in the small bowel causing fat malabsorption, so the fat binds to calcium, leaving a molecule called oxalate free to be absorbed and deposited in the kidneys where it can form stones. Another cause of kidney stones is dehydration, which can be caused by fluid loss from diarrhea. More concentrated urine results from dehydration, which can lead to kidney stones. Symptoms of kidney stones include pain, nausea, vomiting and blood in the urine.

Inflammation in the small bowel can affect the ureters (tubes which carry urine from the kidneys to the bladder) by pressing on the tubes and blocking them, preventing the urine from draining. This makes the kidney swell up, and surgery may be needed to remove the inflamed section of tissue so the urine can flow again.


Some complications are related to the liver and its function.

About one in three people with Crohn’s develop gallstones. These are small stones made of cholesterol which may get trapped in the gallbladder, just beneath the liver, and can be very painful. Several factors linked with Crohn’s can make gallstones more likely – for example, removal of the end of the small intestine or severe inflammation in this area, which can lead to poor absorption of bile salts (which help to digest fat in the gut).

Some of the drugs used to treat IBD (for example, azathioprine and methotrexate) may affect the liver. Changes in treatment may help to reduce this type of complication.

Primary Sclerosing Cholangitis (PSC) is a rare disease that affects up to one in 50 people with CD and one in 13 people with UC. It causes inflammation of the bile ducts and can eventually damage the liver. Symptoms include fatigue, itching, jaundice, and weight loss. Treatment is usually liver transplantation, and a drug called ursodeoxycholic acid can also be used.


People with IBD are more than twice as likely to develop blood clots, including DVT (deep vein thrombosis) in the legs, and pulmonary embolisms in the lungs. You may be particularly at risk during a flare-up or if you are confined to bed, for example in the hospital. If you get pain, swelling and tenderness in your leg, or chest pains and shortness of breath, contact your doctor straight away. You can reduce your risk by not smoking, by keeping as mobile as possible, drinking plenty of fluids, and wearing support stockings. Precautions like these can be especially helpful when traveling by air, which increases the risk of blood clots for everyone.

For more details see Travel and IBD.


Anemia is one of the most common complications of IBD. If you are anemic it means you have fewer red blood cells than normal and/or lower levels of hemoglobin in your blood (hemoglobin is a protein found in red blood cells and carries oxygen around the body).

There are several different types of anemia.

People with IBD are most likely to develop iron deficiency anemia. This can be caused by a lack of iron in the diet, poor absorption of iron from food, or ongoing blood loss. Blood loss from the bowel commonly causes anemia in people with Crohn’s, even if the blood loss is not visible. It is important to try and ensure a good intake of foods containing iron to help prevent anemia.

Another type of anemia is vitamin deficiency anemia, caused by a low intake or poor absorption of certain vitamins, such as vitamin B12 or folic acid. This may particularly affect people with Crohn’s who have had sections of the small intestine removed. Some of the drugs used for IBD (for example, sulphasalazine and azathioprine) can also cause anemia.

If the anemia is very mild, there may be few or no symptoms. With more severe anemia, the main symptoms are chronic (ongoing) tiredness and fatigue. You might also develop shortness of breath, headaches and general weakness. How anemia is treated will depend on its cause. For iron deficiency anemia you may be prescribed iron supplements as tablets or as IV (intravenous) iron, which is given by injection or in an infusion through a drip. Some people with IBD find that they cannot tolerate iron by mouth, so are given IV iron which can be more effective. For vitamin deficiency anemia you may be given extra B12 or folic acid, as tablets or by injection.