Digestive Health

Updated 02 March 2018

Course an prognosis of Crohn's disease

Once you’ve been diagnosed with Crohn’s disease, it’s important to realise that it’s a chronic condition – in other words, it’s a lifelong disease.

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With treatment, inflammation can be managed. 

Most people experience periods of remission, which can be followed by flare-ups. 

The course and severity of the disease varies widely from person to person, which is one of the reasons it's difficult to treat.

These factors can play a role:

Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen and naproxen can worsen Crohn's disease. If you need pain relief, ask your doctor about other options.
Smoking can result in Crohn's disease flare-ups. It also increases the risk of needing surgery.
Stress can exacerbate symptoms of Crohn’s disease. 

Possible complications
Having Crohn's disease increases your risk of developing colon cancer. Therefore, it’s recommended that you undergo a colonoscopy every one to two years. Surgery may become indicated to remove a section of the bowel if the following complications arise:

Bowel obstruction 
A non-healing fistula
Severe side effects from medication
Severe symptoms that can’t be controlled with medication

Bowel obstruction
A bowel obstruction may be due to prolonged inflammation that causes the intestinal wall to thicken. Thickening of the intestinal wall may promote the development of scar tissue, which ultimately narrows the width of the intestinal wall, forming a stricture. Strictures can block digestive contents in the gut, which may require surgery to rectify. 

Some people have inflammatory strictures, where inflammation, not scar tissue, narrows the intestines. Often, medication can reduce the inflammation and resolve this type of stricture. Symptoms include severe cramping, abdominal pain, nausea, vomiting and constipation.

Fistula
Ulcers may form as a result of chronic inflammation. A fistula is a complication that arises when an ulcer extends completely through the intestinal wall and creates an abnormal connection between two different body parts. For example, fistulas can develop between your intestine and skin, or between your intestine and another organ. 

Fistulas that develop in the abdomen are of concern, as the food you eat may not be absorbed properly. In some instances, a fistula can become infected. This can then form an abscess – a life-threatening complication, if not treated. Fistulas near or around the anal area (peri-anal fistulas) are the most common kind in people with Crohn’s disease.

Medication side effects
Drugs such as biologics and aminosalicylates, which act by blocking functions of the immune system, are associated with a small risk of developing cancer (including lymphoma and skin cancer). They also increase the risk of infection.

Corticosteroids are also known to increase the risk of osteoporosis, bone fractures, cataracts, glaucoma, diabetes and high blood pressure, among other conditions. Work with your doctor to determine the risks and benefits of your medication.

Perforations 
Inflammation that extends deep into the bowel wall can cause a stricture (narrowing) to form, which may perforate or rupture. The contents of the bowel can then leak through the perforation (hole). This is a medical emergency that must be treated immediately. 

Symptoms include severe abdominal pain, fever, nausea and vomiting. 

Anaemia
Anaemia (a low number of red blood cells) may occur as a result of chronic bleeding in the intestine or from nutritional deficiencies. The most common form of nutritional deficiency in people with inflammatory bowel disease (including Crohn’s disease) is iron-deficiency anaemia. This is caused either by a lack of iron in the diet or from the poor absorption of iron from food. If you have Crohn’s disease, it’s important to make sure you eat enough iron-rich foods. 

Other nutritional causes of anaemia are also likely in people with Crohn’s. A deficiency in vitamin B6, B2, B12 or folic acid may also result in anaemia due to the poor nutrient absorption. This is particularly common in people who have had sections of their bowel removed. 

The last probable cause of anaemia in people with inflammatory bowel disease is the medication used to treat the condition. For example, sulphasalazine, methotrexate and azathioprine can also cause anaemia.

Extra-intestinal manifestations
Inflammation of the joints (arthritis) is a common complication of Crohn’s disease and is more common in people with Crohn’s colitis (Crohn’s disease in the colon). The inflammation usually affects the large joints of the arms and legs, including the elbows, wrists, knees and ankles.

Medication and physiotherapy may be helpful, and the condition is usually managed jointly by rheumatology and gastroenterology specialists. 

Crohn’s disease can also cause skin problems such as erythema nodosum (a painful disorder characterised by tender bumps or nodules under the skin), pyoderma gangrenosum (a condition that causes tissue to die, leading to deep ulcers – usually on the legs) and Sweet’s syndrome (a rare skin condition, with its main symptoms being fever and painful skin lesions that appear mostly on the arms, neck, head and trunk).

These problems tend to occur during flare-ups, and generally improve with the treatment of Crohn’s.

Eye problems affect some people with Crohn’s disease. The most common condition is episcleritis, which affects the sclera (the white outer coating of the eye). The two other eye conditions associated with Crohn’s disease are scleritis (inflammation of the sclera itself) and uveitis (inflammation of the iris). 

People with Crohn’s disease are at higher risk of developing thinner and weaker bones, which can be diagnosed by a dual-energy X-ray absorptiometry (DEXA) scan. Bone thinning may be due to:

The inflammatory process itself
Poor absorption of calcium from the diet
Poor dietary intake of calcium-rich foods
Smoking
Low physical activity
Use of steroid medication

Patients furthermore have an increased risk of developing kidney stones, and about one in three people with Crohn’s disease develop gallstones. This may be more common in patients whose ileum (the end part of the small intestine) has been removed. 

If you have Crohn’s disease, you’re also at higher risk to develop blood clots, including DVT (deep-vein thrombosis) in the legs and pulmonary embolisms in the lungs. You’re at even greater risk if you’re bedridden or if you experience frequent flare-ups.

Prognosis
Unfortunately there’s no known cure for Crohn's disease, but medical treatment and other therapies can help you manage your symptoms. This, in turn, could result in long-term remission. With treatment, some people with Crohn's disease are able to function well.

When can you return to work or school?
Every person with Crohn’s disease is managed differently according to the extent of their symptoms and the complications associated with the disease. It’s best to talk to the members of your healthcare team about when you can return to work or school. 

Reviewed by Kim Hofmann, registered dietitian, BSc Medical (Honours) Nutrition and Dietetics, BSc (Honours) Psychology, December 2017.