Crohn’s disease is an inflammatory disorder that affects the lining of the gastrointestinal tract or gut. Inflammation is the process by which the body responds to irritation or injury and it can lead to pain, swelling and redness.

Crohn’s disease is a chronic condition, meaning it is ongoing throughout a person’s life. However, a person with this condition may experience periods of remission and good health in-between periods of relapse where symptoms “flare up”. There is currently no treatment that can cure Crohn’s, but medication and sometimes surgery can help to alleviate symptoms.

Researchers are still not sure exactly what causes Crohn’s disease, although it is thought that a number of contributing factors are at play including the genes a person has inherited and an abnormal immune reaction. The latter is probably triggered by something in the environment and suggested factors include diet, viruses, bacteria, smoking and stress.

The inflammation and ulceration seen in Crohn’s disease inhibit the gut’s ability to digest food, absorb nutrients and remove waste in the usual way. The condition can arise in any part of the gut, but it usually affects the last segment of the small intestine (the ileum) or the colon. The inflammation and ulceration is often patchy, with areas of healthy gut found in-between affected areas. An area of inflammation may only be small, affecting only a few centimetres or it may extend along a large portion of the gut. Crohn’s may also develop beyond the gut lining and penetrate deeper into the wall of the bowel. Common symptoms of Crohn’s disease include abdominal pain, diarrhea, tiredness, weight loss and blood and mucus in the stools.

Crohn’s disease is estimated to affect around one in every 650 people in the U.K and is more common in urban than rural areas. It is also more prevalent in developed countries, although it is starting to become more common in developing countries. Disease onset may occur at any age, but the condition usually develops at some time between 10 and 40 years. Crohn’s is slightly more common among women than men, but among children, boys are affected more than girls. The condition is also more common among smokers than non-smokers and among white people than Asian people. It is most common in Jewish populations of European descent.

The main forms of Crohn’s disease are terminal ileal and ileocaecal Crohn’s. Terminal ileal Crohn’s affects the terminal or end of the ileum. If the beginning of the large bowel is also affected, the condition is referred to as ileocaecal Crohn’s. Crohn’s in the ileum makes it difficult for the body to absorb bile salts which instead irritate the bowel lining, causing watery diarrhea. Other symptoms include pain in the lower right side of the abdomen and weight loss.

The treatment used to manage Crohn’s disease may be medical, surgical or a combination of these. In cases where the condition is mild, no medication may be required and sometimes dietary changes are enough to alleviate symptoms. Medication is generally used to reduce the symptoms of Crohn’s and prevent relapses once the condition is under control. This can mean patients need to take their medication on an ongoing basis, sometimes for many years. In other cases, only a short course of medication is required.

The drugs most commonly used to treat Crohn’s are anti-inflammatories, antibiotics and symptomatic medications. Anti-inflammatory drugs may take the form of an aminosalicylate, a corticosteroid, an immunosuppressant or a biological therapy.

Biological therapies are often used when other medications have failed to work or have been causing adverse side effects. They may also be used when surgery is not considered a suitable option for the patient. An example of a biological therapy is infliximab and this is used to treat severe and active forms of Crohn’s disease.

Infliximab works by blocking a protein called TNF-α (tumor necrosis factor-alpha), which is an important protein produced by the body as part of the immune response. It helps the body to fight infection by causing temporary inflammation in affected areas. Researchers suspect that the chronic inflammation seen in inflammatory bowel diseases such as Crohn’s may be caused by an overproduction of this protein. Also known by the brand name Remicade, infliximab binds to TNF-α, which suppresses inflammation and alleviates symptoms.

Infliximab is manufactured as a powder, which is turned into a liquid and administered by intravenous infusion. The infusion takes about two hours, although some clinics can now carry out faster infusions that only take an hour or less. People usually receive an initial infusion, followed by a second two weeks later and a third six weeks later. If a patient responds well to the treatment, they may be put on a maintenance programme and receive an infusion every eight weeks. Patients are then reassessed every 12 months. With infliximab therapy, symptoms may start to improve anywhere from within a few days to up to six weeks after the initial treatment.