Crohn's disease

Updated: 21 October , 14:24
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Christian Trautwein

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Definition and causes

Crohn's disease is a chronic condition of the gastrointestinal tract, characterized by the development of an inflammatory process in one or the other region, with local or systemic complications.

Disease prevalence

Crohn's disease is more common in people living in developed countries. The incidence is 6-8 cases per 100,000 people per year. In most cases, the initial diagnosis occurs between 20-40 years of age, and is less common after 50 years of age. Crohn's disease may be diagnosed in patients younger than 20.

Causes of the condition

There is no definite cause of the illness. Specialists have identified the most likely hypotheses for the mechanism by which inflammatory bowel disease develops:

  • genetic predisposition; in particular, certain NOD2 mutations increase the likelihood of pathology by a factor of 20-35;
  • influence of environment, e.g., in northern regions the pathology is more common;
  • immune system disorders, such as an uncontrolled immune response that provokes an inflammatory process.

The condition is multifactorial and the exact cause cannot be determined.

Risk factors

There are risk factors that increase the likelihood of disease:

  • age of the person - adolescents and adults (15-35 years old) are more likely to be affected;
  • race - whites are more likely to be affected;
  • smoking does not only increase the risk of Crohn's disease, but also worsens the prognosis;
  • appendectomy - previous surgery increases the likelihood of the disorder.

Disease signs

Crohn's disease involves the mucosa of any part of the gastrointestinal tract. In 65-70% of cases, the ileum and ileocecal valve (the area where the small intestine passes into the large intestine) are affected. Segmental colitis and rectal involvement occur in 20% of cases. In one in five cases, the entire colon is affected.

Clinical pattern of the disease

The symptoms of Crohn's disease depend on the localisation of the inflammatory process. Characteristic are:

  • diarrhoea;
  • abdominal cramps that intensify after meals;
  • pain in various locations;
  • severe flatulence.

Latent bleeding may develop, indicated by anemia. These patients often refuse to eat, which results in severe weight loss.

Inflammation progress and the involvement of nearby tissues lead to the formation of fistulas, i.e., abnormal connections between the cavities. This leads to the development of an abscess with fever and a high risk of sepsis (blood poisoning).

Extraintestinal symptoms occur in one in five cases and include inflammation of the mucosa of the eyes, bile ducts, liver, joints and skin rashes.

Classification and stages of development

There are many classifications of the disease, but almost none of them meet all doctors' requirements. Crohn's disease is classified:

  • by localisation of the process - enteritis, colitis, duodenitis, enterocolitis, gastritis, etc;
  • by severity: mild (no general disturbance), moderate (moderately severe symptoms) and severe (severe symptoms, complications);
  • by course: acute and chronic.


Patients with Crohn's disease are always at risk of developing life-threatening complications if left untreated. The following consequences require urgent medical attention:

  • intestinal obstruction, when the products of digestion cannot move to the lower intestine due to scarring and swelling;
  • perforation of the intestinal wall, i.e., formation of a defect with the products of digestion escaping into the abdominal cavity;
  • bleeding of varying severity;
  • toxic megacolon - a sharp increase in the lumen of the large intestine.

A separate case is complications in which emergency treatment is not required. These include stenosis or narrowing of the lumen, abscesses, fistulas, mucosal cell dysplasia and cancer.

Crohn’s disease: diagnosis

Assessment of Crohn's disease signs and objective findings is not enough for identification. Laboratory and instrumental exams are recommended to confirm the diagnosis.

Laboratory tests

In addition to standard blood tests, a test for inflammatory markers - C-reactive protein and lactoferrin levels - is necessary. A stool test for calprotectin and lactoferrin is mandatory. A microbiological examination for bacterial flora and parasites is prescribed to rule out infection.

An albumin test is also helpful, especially in preparation for surgery.


The procedure involves using an endoscope to visually inspect the mucous membranes. It is used to assess the entire intestine and to rule out lesions in the upper digestive tract. During the endoscopic examination, specimens are taken for histological examination.

Radiology exams

The following imaging tests may be used in Crohn's disease:

  • ultrasound - prescribed for acute conditions and monitoring the effectiveness of treatment;
  • intestinal X-rays are useful in an emergency when obstruction or perforation is suspected;
  • Magnetic resonance imaging can detect abscesses, fistulas (MRI is indicated in all patients with a high disease risk);
  • Computed tomography is also highly informative, but due to the radiation it is used less frequently, and is more often used to prepare a patient for surgery.

There may be cases where doctors prescribe various other examinations, causing the patient to question their usefulness. A second opinion from European doctors can help clarify the situation. An online consultation will help you to understand whether the tests and examinations that have been prescribed are really necessary.

Differential diagnosis

In patients with Crohn's disease, it is important to rule out other conditions, such as irritable bowel syndrome, infectious lesions of the digestive tract mucosa, and ulcerative colitis. Pain in the lower abdomen may indicate appendicitis and pseudotuberculosis. Granulomas may form on the intestinal mucosa in sarcoidosis. Stenosis is characteristic of bowel cancer and lymphoma.

Treatment of Crohn’s disease

If there are no complications, Crohn's disease can be treated with drugs in combination with a diet. The first step is to get rid of the symptoms of the disease. Loperamide and drugs from the antispasmodic group can help with diarrhea and painful cramps. Crohn's disease patients should take these medicines before meals to increase their effect. A low-fiber diet is essential. Diphenoxylate, tinctures of opium or codeine have also been successful in controlling diarrhea.

The next step in Crohn's disease is to suppress the symptoms of inflammation. The doctor prescribes medicines from the aminosalicylate group for this purpose. Mesalamine, Balsalazid, Olsalazine are highly effective.

The effect is particularly pronounced if the large intestine is affected.

Corticosteroids will be equally effective. They are preferably administered as intravenous injections, to avoid the stomach. They can relieve such symptoms as abdominal pain, cramps, diarrhea and fever in the acute period. The drugs are usually used in high doses at the beginning, and only when the condition has stabilized is the dosage reduced, or the treatment is stopped. In addition to intravenous administration, corticosteroids may be used in the form of enemas and foams.

Immunosuppressants are also used. Patients in whom the above-mentioned treatment is unsuccessful may get Azathioprine and Mercaptopurine. They suppress the immune system, allow the dosage of corticosteroids to be reduced, and increase the duration of remission. It is important to remember that immunosuppressants can cause side effects.

Methotrexalate is used in the case of corticosteroids intolerance. It is important to rule out pregnancy in women and use effective contraception during therapy.

For Crohn's disease fistulas, treatment must include high-dose cyclosporine. It has a high risk of side-effects and should therefore be used in short courses. Tacrolimus is also highly effective.

Biologics are increasingly being used. Monoclonal antibodies can affect the immune system in patients with moderate to severe disease. Infliximab, a drug in this group, allows the symptoms of the disease to be relieved when other tactics are not effective. Adalimumab, sertolizumab and vedolizumab are also related drugs. The former two can be administered subcutaneously, which reduces the risk of side-effects during infusion.

Crohn's disease may also require the use of antibiotics. In most cases, Metronidazole is used to eliminate bacterial flora in fistulas and abscesses.  Ciprofloxacin and Levofloxacin can also be used in addition or as a monotherapy. In cases where Crohn's disease is in the active phase, the non-resorbable antibiotic Rifaximin is prescribed.

If severe, Crohn's disease requires hospitalization and parenteral nutrition. Blood transfusion is indicated for bleeding.

If there is no effect, or if complications develop, Crohn's disease requires surgical treatment. Removing the affected part of the intestine helps to alleviate the condition, but does not get rid of it. There is always a risk that symptoms of the disease will develop with other parts of the body being affected. Often, the first operation is followed by a second or third one after some time. Therefore, it is extremely important to determine whether surgical treatment is advisable. When in doubt, it is advisable to listen to the opinion of other doctors, and the best option is to get a second opinion from specialists at European clinics.

After completion of the treatment course, supportive therapy is necessary. Aminosalicylates and antibiotics are prescribed permanently in combination with a diet to keep Crohn's disease in stable remission.

Crohn’s disease: prognosis and prevention

Crohn's disease is steadily progressive, so the prognosis is generally unfavorable. According to statistics, 90% of cases develop complications of varying severity 10 years after diagnosis. In almost half of the cases, surgical treatment for Crohn's disease is required. In patients who have undergone surgery, only 55% experience a sustained remission within 10 years.

As the cause of the inflammation is not exactly known, no effective prophylaxis plan can be devised. After remission, it is important for patients to see their doctor regularly to detect a recurrence in good time.

Second opinion

A second opinion from doctors in Europe may be needed in various cases:

At the diagnostic stage. It allows you to determine the appropriateness of the procedures prescribed, and to assess the results of the tests.

At the stage of prescribing therapy. It allows you to ask the opinion of another doctor about the drugs prescribed, their dosage and their combination with other treatments.

During treatment. Consult with other doctors about possible side effects, the body's reaction to the prescribed medication, and evaluate the effectiveness of therapy.

At the stage of rehabilitation after surgery. Gives you an opportunity to hear another doctor's opinion about rehabilitation, maintenance therapy and relapse prevention.

Psychological support. Especially important if the attending physician is aloof and does not provide moral support. A second opinion enables the patient to learn the prognosis from other, more experienced doctors, and to become acquainted with cases of complete recovery.

In this way, the possibility of consulting other doctors enables the patient, without having to travel to other countries, to find out more information about his or her case.

Crohn's disease is chronic, but with the right approach a stable remission can be achieved, allowing the person to return to active life. It is important to choose the right treatment and prophylactic strategies, and it is better to rely on the opinion of several doctors rather than being limited to the attending specialist.


How Crohn's Disease Is Treated. By Amber J. Tresca Updated on December 23, 2021. 

Crohn's disease.

Crohn's disease: a population-based study of surgery in the age of biological therapy. 

Crohn's Disease: Diagnosis and Management. 

Image source: Free Stock photos by Vecteezy


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Comments — 1

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Галина Ильченко
Галина Ильченко

Если у тебя болезнь Крона, ты не можешь бездумно что-нибудь съесть. Я точно знаю, что именно мне кушать нельзя: очень соленое или сладкое, очень холодное или горячее, очень острое или жирное, а также жареное или трудное для переваривания, например, цельнозерновые продукты. После тушёного, пареного проблем обычно нет. Если пробую что-то новое, то в минимальных количествах, так и определяю, что подходит, а что нет.

Please avoid self-diagnosis and self-medication!

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