Crohn’s disease is a chronic inflammatory bowel disease. It can be located anywhere in the digestive system, but usually it is in the end of the small intestine and in the large intestine. Most common symptoms include abdominal pain, diarrhea, bloody stools, fever and weight loss. The diagnosis is made based on a colonoscopy and biopsies. The illness is treated with medication and in severe cases with surgery. Crohn’s disease is not contagious.
The cause of Crohn’s disease is unknown. The illness can start at any age, but usually in younger years (15-35 years), and it is a little bit more common in women than in men. Genetic factors play a role, and it is believed that some environmental factor triggers the illness in persons who are genetically predisposed. In Crohn’s disease patients, the intestine’s own immune system reacts exceptionally strongly to inflammation caused by an external stimulus and remains “switched on”.
The prevalence of Crohn’s disease has increased greatly as the Western living conditions and lifestyle have changed. The scarce natural microbial contacts in infancy and dietary factors have been suggested as a reason. Although many patients experience that some foods cause bowel symptoms, no cause for the illness has been found in diet. Crohn’s disease cannot be cured with a diet.
Smokers have a higher risk of getting Crohn’s disease, and the illness is often more complicated in smokers. Psychological factors have not been proved to cause the illness, but stress increases symptoms. Sometimes Crohn’s disease in the large intestine is difficult to differentiate from ulcerative colitis. In such cases, the condition is called indeterminate colitis. The differential diagnosis, however, does not affect treatment.
The most common symptoms of Crohn’s disease are abdominal pains, diarrhea, weight loss and fever. Other symptoms include fatigue, nausea, vomiting, bloody stools, obstruction symptoms, joint pains and ailments in the mouth and anal area. The symptoms can be continuous or recur every few weeks, months or even years, disappearing in between. The symptoms depend on the extent, severity and location of the inflammation.
In children, delayed growth and development or aphthous ulcers and mucous membrane changes can be the first symptoms of Crohn’s disease.
In addition to digestive tract symptoms, there can be symptoms of joints, skin and eyes.
IBD patients’ follow-ups are done at gastroenterology, internal medicine or pediatric outpatient clinics in hospitals, health care centers or other medical centers. IBD is diagnosed using biopsies taken from the intestinal wall in a colonoscopy. Colonoscopies are also done to follow up the response to treatment and later to find anaplasias that can develop into cancer.
In addition to colonoscopy (examination of the large intestine), a gastroscopy (examination of the upper digestive tract) or enteroscopy (examination of the small intestine) may often be necessary.
A capsule camera that is swallowed can be used to examine the entire small intestine, but it cannot take biopsies and cannot be done if the patient has strictures. Computerized tomography (CT) or magnetic resonance imaging (MRI) is used to examine Crohn’s disease in the small intestine.
The course of the illness and response to treatment is also followed up with laboratory tests from whole blood, blood serum, urine or stool samples.
Medication is decided based on the severity or the extent of the illness. The National Health Insurance (Kela) pays lower special reimbursement (65 %) for most IBD medicines. You need a medical certificate to get the marking on your Kela card that gives you the reimbursement.
In self-directed treatment, medication is increased when symptoms appear following instructions that have been discussed with the doctor. The clinic is contacted if necessary.
According to studies, 5-ASA or mesalazine (Pentasa®, Asacol®) does not significantly decrease inflammation in Crohn’s disease. It can still be used to prevent flare-ups.
The active ingredient in SASP or salazosulfapyridine (Salazopyrin ®) is mesalazine, which is transported to the large intestine by sulfapyridine. Sulfa may cause allergic reactions and have harmful effects on male fertility.
When the illness flares up, a treatment with cortisone (Prednison®, Lodotra®, Prednisolon®, Entocort®, Budenofalk®, Colifoam®, Solomet®, Solu-Medrol®, Medrol®) is often started either as tablets, rectal foam or for inpatients as injections or infusions. Cortisone alleviates inflammation and usually eases the symptoms quickly, but it also has an immunosuppressive effect. Long-term use is not recommended due to side effects.
Immunosuppressive medication (Azamun®, Imurel®, Merkaptopurin®, Trexan®, Metoject®) is used if 5-ASA or cortisone medication do not work. The response to immunosuppressive medication develops slowly during 3-6 months, and the treatment is continued at least 3-5 years.
Biologic medications (Humira®, Remicade®, Entyvio®, Remsima®, Inflectra®) can be used to treat severe Crohn’s disease. They affect inflammation transmitters or block the white blood cells that maintain inflammation. Some biologic medications are given as infusions in hospitals, others are injected at home. Biosimilars are precise copies of biologic medicines and have similar safety and efficacy profiles.
Antibiotics are used as primary treatment only for fistulas and abscesses.
Over-the-counter NSAIDs (non-steroidal anti-inflammatory drugs), such as ibuprofen or ketoprofen can aggravate Crohn’s disease and increase bleeding. Paracetamol is a safer option to use for fever and as painkiller.
In pediatric Crohn’s disease, the same medications are used as for grown-ups. However, issues such as the effect on growth need to be taken into account when choosing medication.
Crohn’s disease cannot be cured with surgery. The illness often recurs at the suture line or moves to a new are, and surgical treatment must aim at saving as much of the intestine as possible. The reason for surgery is usually a stricture, an obstruction, an abscess or severe inflammation that does not respond to medication. Severe bleeding, perforation of the bowel or fistulas can also lead to surgery, as well as continuous anemia, pain, malnutrition or anaplasia (cancer risk).
About a quarter of Crohn’s disease patients are operated within the first five years and half within 20 years. About a half of those who have been operated will have to be operated again. It is always better that the surgery is pre-planned, and a good general condition and nutritional state promote recovery. It is recommended that the patient quits smoking before surgery, and alcohol should be consumed within limits.
As much of small intestine as possible should be saved, because it is an important factor in the absorption of nutrients. Usually, only the part of the bowel with ailments is removed. The large intestine has an important role in maintaining fluid balance and it is not removed entirely if a part of it is healthy. Sometimes a temporary ostomy is necessary to settle the inflammation. In case of severe rectal Crohn’s disease, the entire rectum may have to be removed and the patient will need a permanent ostomy.
The biggest risk for those who had surgery is that the suture line fails, there is an obstruction or the wound gets infected. Continuation of medication is decided individually. It is good to have a colonoscopy within a year to check the suture line as the illness often recurs there.
Having a surgery is often postponed because the patient is afraid of it and the possibility of an ostomy. Most patients think later, however, that they should have had surgery much earlier.
Complications and co-morbidities
Crohn’s disease can cause strictures in the bowel, and if an obstruction forms in them, the symptoms include pain that comes and goes in waves, constipation, gurgling in the bowel, nausea and vomiting. The doctor must be contacted immediately. Fistulas (passages) can form through the intestinal wall to the skin, between parts of the bowel or to adjacent organs. Fistulas can ooze continuously or occasionally pus, stool or even blood. A rare complication is a perforation of the bowel, which requires urgent surgery because a peritonitis can develop quickly.
Fissures are painful, chronic ulcers in the anal area. They can excrete blood or interstitial fluid. In Crohn’s disease patients, any ulcer in the anal area can develop into a chronic fissure, which is why unnecessary procedures in the area must be avoided.
In all phases of Crohn’s disease the patient may have various joint symptoms, most often arthralgia (joint pain). Sacroilitis (inflammation of the joints where the lower spine and pelvis connect) and ankylosing spondylitis can show symptoms independent of the phase of the illness. Arthritis (joint inflammation) is usually only present in the active phase of IBD. When joint symptoms appear, the possibility of other rheumatic diseases is ruled out.
Skin and eye ailments are also possible. Erythema nodosum causes purple, tender lumps especially in the legs and arms. Pyoderma gangrenosum is rarer and causes deep ulcers on the skin. Eye ailments include episcleritis (inflammation of the thin layer of tissue covering the white part of the eye) and iritis (inflammation of the colored ring surrounding the pupil).
Other possible co-morbidities are pancreas inflammations and kidney changes. Crohn’s disease patients also have a higher risk of venous thrombosis, pulmonary embolism and pericarditis. A chronic inflammation in the large intestine can increase the risk of colon cancer. This is why it is important to have regular colonoscopies even if the illness causes no symptoms. The most common liver ailment is primary sclerosing cholangitis (PSC), which causes scarring within the bile ducts.
Crohn’s disease in or removal of the end of the small intestine often causes diarrhea due to bile acid malabsorption and anemia and nervous symptoms due to vitamin B12 deficiency. Bile acid diarrhea can be managed with medication and vitamin B12 can be given as injections.
Active IBD that causes mucosal bleeding may often lead to iron deficiency anemia. Iron can be taken as tablets or given intravenously.
Living with Crohn’s disease
Most Crohn’s disease patients can live a fairly normal life. Average life expectancy is same as in other people. During flare-ups, the illness may limit the ability to study and work, but it rarely leads to long-term disability. The illness should be considered when choosing a career: heavy physical work and irregular shift work may cause problems. When changing jobs, it is important to mention the illness. The occupational health physician will estimate whether the illness affects the work ability. Not telling about the illness can even lead to termination of contract, if the illness significantly disturbs working.
Intestinal bacterial infections may activate the illness. Especially when travelling it is important to avoid traveler’s diarrhea. Good hand hygiene decreases the risk also if someone in the family has a stomach flu.
Smoking doubles the risk of recurrence and surgery and weakens the efficacy of e.g. biologic medications. Crohn’s disease patients need to take care of their immunization and booster doses. As medicines that affect the immune system weaken their efficacy, vaccines should be taken before the medication is begun. “Living” vaccines must not be given to those on biologic medications.
Stress may worsen symptoms. Stress and pain management can be learned through different relaxation methods. The efficacy or harms of various alternative treatments have not been shown in scientific studies, and their use should be mentioned to the doctor. The treatments and medications prescribed by the doctor must be taken as prescribed and should not be stopped alone. Medication must be taken care of also during remission to prevent symptoms from recurring.
Pregnancy runs usually as normal, but is it good to discuss such plans first with the doctor. Severe inflammation may make it difficult to get pregnant and increase the risk of miscarriage, and pregnancy should be timed during a remission period. Ostomy is not an obstacle. Medication can usually be continued throughout pregnancy.
If the illness is under control, it does usually not prevent military service. If the disease is in a difficult phase, it is possible to postpone military service or even be exempted from it. It is good to bring a doctor certificate to the drafting event.
No single foodstuff increases the risk of Crohn’s disease or triggers a flare-up. Some foods may, however, individually cause symptoms of the digestive tract. Dietary treatment is used for children; in grown-ups, Crohn’s disease is treated with medication. Good nutritional state, however, supports recovering from flare-ups and improves general well-being.
While in remission, Crohn’s disease patients can usually eat normal food. Absolute dietary limitations are needed only rarely; usually limitations are individual. It is usually enough to eat less of the foods that cause symptoms. If a food that is essential for nourishment, it is important to find a substitute for it. Otherwise, a limited diet can lead to malnutrition.
In addition to Crohn’s disease, patients can have functional stomach ailments that do not disappear even in remission. Dietary limitations cannot prevent flare-ups, but they may help in alleviating symptoms. No instructions can be about a diet that would fit everyone; the diet is tailored from individually suitable foods.
During flare-ups patients might not have proper appetite, and foods that can normally be eaten may worsen diarrhea and abdominal pains. Foods that contain lots of fiber and are difficult to digest should be left out. For recovery, however, it is important to eat regularly and have a balanced diet. If it is difficult to eat solid foods, liquid diet or dietary supplement drinks sold in pharmacies may be helpful. Gastric feeding tubes or intravenous feeding may also be used.
During diarrhea it is important to drink enough. Diluted drinks that still contain salts and sugar are best, for example diluted juices, tea, mineral water, beef or vegetable broth and juice soup. If the patient has so-called fat diarrhea, fats need to be decreased in the diet and other foodstuffs increased or dietary supplements advised by a nutritionist used to ensure sufficient energy intake.
In more severe cases, dietary treatment is tailored individually. A nutritionist helps in planning and carrying out the diet. Supplements are used when necessary.