Crohn’s disease is a chronic inflammatory disease. This was named after its discoverer (Burrill Bernard Crohn). Crohn’s disease can occur in the entire digestive tract (from the mouth to the anus) at several sites at the same time (discontinuous), but preferentially in the terminal region of the small intestine (= terminal ileum, hence ileitis terminalis) and initial region of the colon. The inflammation affects all wall layers of the intestine (not only the mucosa as in ulcerative colitis).
Crohn’s disease: causes and triggers.
Despite intensive research, no clear cause of Crohn’s disease has been identified to date. The marked increase in cases of Crohn’s disease in recent years may be associated with greatly improved hygienic conditions. It is assumed that in the absence of immune stimulation by intestinal parasites (worms), the immune system does not learn to distinguish own from foreign. As a result, the immune system attacks its own structures (e.g. intestinal cells), which leads to chronic inflammation. Whether this assumption is correct remains to be seen. Familial accumulation indicates that genetic factors also play a certain role in Crohn’s disease. Certain pathogens (bacteria and viruses) may have a role in triggering the autoimmune mechanism. The influence of psychological or physical stress situations on the development of Crohn’s disease seems obvious. Smoking also appears to be a risk factor that promotes the development of Crohn’s disease and also negatively influences its course.
Crohn’s disease: symptoms and signs
Although the entire digestive tract can be affected by Crohn’s disease, the majority of cases involve the small intestine and colon. Inflammation of all wall layers results in thickening with narrowing of the intestinal diameter. Signs of Crohn’s disease also include ulcers and fissures in the intestinal layers. Particularly during an episode, patients often suffer from symptoms such as abdominal pain and fever, often associated with general fatigue. Although Crohn’s disease can occur without diarrhea, it is usually a frequent companion of the disease. Watery diarrhea often occurs. However, blood in the stool occurs very rarely. Pain characteristics and localization (usually right lower abdomen) can be very similar to appendicitis, which is why a thorough evaluation by a physician is particularly important.
Crohn’s disease: diagnosis
In addition to clinical clues (the experienced physician pays attention to anal fistulas, which are often the first symptom), apparative examination methods have great importance in the diagnosis of Crohn’s disease:
- With colonoscopy, the typical changes are visible and can be localized.
- By simultaneously taking a tissue sample, the Crohn’s disease findings can be confirmed under the microscope.
- To obtain an overall view of the digestive tract, an X-ray is taken after contrast enema. This allows the individual disease foci can be better identified.
- Ultrasound is also used to visualize the thickened intestinal walls.
- In the acute episode, blood laboratory values show the typical signs of inflammation (many white blood cells and few red blood cells, high blood sedimentation rate).
- To be able to exclude a bacterial cause of the infection, the stool must be examined. If the value of the proteion calprotectin in the stool is increased, there is inflammation in the intestine.
The distinction from other chronic intestinal diseases, such as ulcerative colitis and diverticulitis or appendicitis, is usually achieved by a thorough history and examination of the patient. However, the calprotectin level also provides an important clue, as it is not elevated in IBS. Circulatory disorders of the intestine can also cause inflammatory changes, especially in older patients. After tumor irradiation in the abdomen, the intestinal loops also often appear thickened and inflamed.
Crohn’s disease: life expectancy and progression.
Crohn’s disease progresses in episodes. Periods of high activity are followed by pauses during which the disease is less symptomatic. For example, the likelihood of a flare-up after a rest period of one year is 30 percent, and after two years of rest it is as high as 40 percent. In the clinic, activity is determined with the help of an activity index.The average life expectancy of Crohn’s disease patients is not lower than that of healthy people if they receive optimal therapy. Unfortunately, the probability that Crohn’s disease will disappear completely is quite low. The regular recurrence of disease relapses often brings complications and often makes surgical intervention unavoidable. However, a cure is not possible as a result (in contrast to ulcerative colitis).
Complications of Crohn’s disease
Because this autoimmune disease affects the entire body, signs of it can be found:
- On the skin (redness, ulcers).
- On the joints (arthritis, inflammation of the spine).
- On the eye (inflammation inside the eye).
- On the liver (inflammation of the biliary vessels).
The impaired absorption of nutrients and vitamins by the intestine and frequent diarrhea can lead to weight loss and nutrient deficiencies. If there is a calcium deficiency, the risk of osteoporosis increases. In children, growth retardation may also occur. In advanced disease, there is a risk of narrowing (stenosis) of the intestine, which can lead to complete intestinal obstruction. Perforations of the bowel are less common in Crohn’s disease. Fistulas are particularly unpleasant and painful, and are most common around the anus. They provide a connection between the colon and the anus (the area around the sphincter). If the fistula becomes blocked, an abscess may form. After years of disease, colon cancer may develop. However, this risk is lower in Crohn’s disease than in ulcerative colitis.
Crohn’s disease: treatment and therapy
Crohn’s disease therapy consists, on the one hand, of adherence to a special diet. If the large intestine is affected, aminosalicylates are used in conjunction with cortisone. If the small intestine is affected, cortisone is effective in the acute episode. The dosage is adjusted according to the severity of the attack. In addition, in severe cases of Crohn’s disease, antibiotics and immunosuppressants (drugs that suppress the immune system) are also administered. Various nutritional supplements may also be used to compensate for nutrient deficiencies. Because of the relatively common complications (perforation, intestinal obstruction, fistulas), surgical treatment is not uncommon. Since a cure for Crohn’s disease is not possible, surgery is performed gently with removal of only short sections of intestine and subsequent joining of the intestinal ends. In addition, it may be necessary to close fistulas or remove abscesses. Chronic inflammation can also lead to the formation of constrictions in the intestine. In this case, the treating gastroenterologist must widen the narrowing with the help of a balloon. Psychological support can also be used to mitigate the negative influence of stress on the course of the disease and to help those affected to better adjust to living with the disease.
Preventive measures
Appropriate diet in Crohn’s disease and good medical (including psychological) care can favorably influence the course of the disease, but it is not possible to prevent it. Immunomodulatory measures (using intestinal parasites) are still in the testing phase but could play a key role in intervening in the mechanism of Crohn’s disease development.
