What is it?
The group of Inflammatory Bowel Diseases (IBD) encompasses Crohn's disease (CD) and Ulcerative Colitis (UC). CD is characterized by a chronic inflammation of one or more parts of the digestive tract, from the mouth, passing through the esophagus, stomach, small and large intestine, to the rectum and anus. In the majority of the cases of CD, however, there is inflammation of the small intestine; the larger intestine, isolatedly or separately, may or may not be involved. The disease is named after the physician who described it in 1932.
How does it develop?
So far CD's causes are not known. Many studies tried to relate it to environmental, alimentary or infection factors, as those responsible for the disease. However, it was observed that smokers are 2-4 times more likely to develop the condition, and that some particularities of the intestinal flora (microorganisms living in the intestine and helping digestion) and of the immune system (the body's natural defense devices) might be related. None of these factors, isolatedly considered, could explain why does the condition sets in and develops. The data set available so far suggests the influence of other environmental and genetic factors. The influence of the genetic factors is noted in first-degree relatives of an affected individual, because they are 25% more likely to also develop the condition than an individual without affected relatives.
How does one feel?
Crohn's disease usually begins around the ages 20 to 30, although a few cases have been reported in babies and late-onset cases in old age. The most frequent symptoms are diarrhea; abdominal pain with colic accompanied by nausea ad vomit, mild fever, feeling of abdominal distension, which is worsened after eating, weight loss, overall malaise and fatigue. Occasionally, blood, mucus or pus, may be eliminated with the feces. The disease alternates periods of remission, without any symptoms, with periods of exacerbation, of unpredictable onset and duration.
Other manifestations of the disease include fistulas, which are abnormal communications allowing the passage of feces between the two parts of the intestines, or the intestine and the bladder, the vagina or the skin. This situation, in addition to being uncomfortable, exposes the individual to recurrent infections. Fistulas occur isolatedly or in association with other diseases affecting the area surrounding the anus, such as anal fissures and abscesses.
Over time, complications of the disease may occur including, among the most common ones, abscesses (pus pouches) inside the abdomen, intestinal obstruction caused by narrowed passages – caused by inflammation or by adherences of inflamed parts of the intestines. Also, malnutrition and biliary calculi may be present due to the malabsorption of certain substances. Other complications, though less frequent, are cancer of the large bowel and bleeding in the digestive tract .
Some patients suffering from CD may present evidence outside the digestive system, such as manifestations on the skin (erythema nodosus and pyoderma gangrenous), eye inflammations, joints (arthritis) and blood vessels (thrombosis or embolism).
How does the doctor make the diagnosis?
The diagnosis is based on both the patient's history and the clinical examination. Where CD is suspected, constrast radiographs of the small intestine (intestinal transit) may help with the diagnosis definition through the findings of characteristics ulcerations, narrowings and fistulas. The large intestine is also typically examined by means of the barium enema technique (contrast x-ray inserted into the rectum) or colonoscopy (endoscopy). This latter test, which consists in the passage via rectum of a hose-like device allowing the inside of the large intestine to be made visible on x-ray film, has the advantage of allowing, as well, the performing of biopsies of the intestinal mucosa to be analyzed under the microscope.
More recently, two blood tests, known by their acronyms ASCA and pANCA, though not confirmatory and having their use limited by their cost, may already be used in the diagnosis of CD.
How is it treated?
The treatment of the disease is individualized, according to the manifestations of the disease in each patient. As here is no cure, the purpose of the treatment is the control of the symptoms and its complications.
There are no food restrictions to be made for all cases. In some patients, intolerance to certain foods, frequently lactose (from milk), has been reported. For these cases, it is recommended to avoid the food, which can cause diarrhea or the worsening of other symptoms. While individuals suffering from a large intestine condition may benefit from a fiber-rich diet, for individuals with intestinal obstruction, a fiber-free diet may be indicated.
In addition to adaptations to the diet, specific medication may also be used in order to control the diarrhea with a reasonable success. The use of these medications must always be ordered by a physician, since there are severe complications associated with their inadequate use. Specific medications acting especially on the control of the immune system are used in the treatment of cases that do not satisfactorily improve, unless they are prescribed diet and antidiarrheal drugs. Due to their cost and side-effects, the decision about the beginning of their use, the maintenance and the choice of medication must be made by a physician with expertise on the subject, by taking into consideration the patient's individual aspects.
Some patients with severe episodes, who do not improve with the use of medication to the maximum dose and for the required time, may need to undergo surgery to remove the affected portion of the intestine.
Situations also requiring surgery are severe bleedings, intra-abdominal abscesses and intestinal obstructions. Although physicians try to avoid surgery altogether in patients suffering from CD, over half of patients will need, at least once in their lifetime, to undergo a surgery. Successive removals of intestine portions may result in difficult food absorption and hard-to-control diarrhea
How can it be prevented?
There is no way to prevent Crohn's disease.
Individuals already affected are strongly advised not to smoke in order to avoid new exacerbations. The chronic use of medications administered to control the crises did not show the same benefit in preventing new episodes and, therefore, the maintenance or suspension of the treatment, after the control of the initial symptoms or its exacerbation, must be individualized.