La maladie de Crohn


Crohn's disease is one of two inflammatory bowel diseases along with ulcerative colitis, also called ulcerative colitis. Crohn's disease is a chronic inflammation of the intestine that usually affects the last part of the small intestine (ileum), the large intestine (colon), or both. However, it can occur all along the digestive tract, from the mouth to the anus. The involvement of the digestive tract is discontinuous with the presence of diseased sections and healthy sections alternating.


There are different risk factors associated with the development of Crohn's disease. In fact, the disease is most commonly seen in smokers, people with other family members affected by the disease, and Ashkenazi Jews. However, the disease affects both men and women. The majority of people develop the disease before the age of 30, but it can also occur later in some.


The exact cause of Crohn's disease is unknown. The disease could be linked to a malfunction of the immune system causing the gut to overreact to an environmental, food or infectious agent and leading to its inflammation.


Symptoms of the disease occur intermittently. This is because people with the disease alternate between periods of remission and periods of relapse when the disease is active. Periods of relapse occur throughout life and can vary in intensity and duration. In adults, the main symptoms are abdominal pain (cramps), diarrhea, loss of appetite, weight loss and fever. In children, abdominal pain and diarrhea may be absent. The main symptoms may be stunted growth, inflammation of the joints, fever, or fatigue caused by anemia.


The diagnosis of Crohn's disease is based on the presence of the above symptoms, a colonoscopy and imaging tests. Additional analyzes are also performed to detect certain complications.


Colonoscopy is a test done with a probe fitted with a camera and inserted through the anus. It allows you to examine the intestines and more particularly the colon.

Imaging exams

Imaging tests usually include computed tomography (CT) or magnetic resonance imaging (MRI) of the abdomen. These tests are another way of examining the intestines.

Complementary analyzes

These tests are not diagnostic but they can highlight certain complications of the disease. For example, blood tests can check for complications such as anemia or the presence of inflammation. The dosages of vitamins and minerals make it possible to detect nutritional deficiencies.

Nutritional consequences

The nutritional status of individuals with Crohn's disease can be characterized by protein-energy malnutrition and deficiencies in nutrients, vitamins and minerals.

Protein-energy malnutrition

The causes of protein-energy malnutrition include insufficient food intake, malabsorption, increased bowel loss, increased energy requirement, and disease activity. Food intake may be inadequate due to anorexia or fear of increased digestive symptoms. Malabsorption is mainly due to resection and / or inflammation of the intestine and the interaction with certain drugs used to treat the disease. The increased intestinal losses are mainly due to diarrhea and blood loss. Finally, energy needs are increased by inflammation, fever or growth in children.

Deficits in nutrients, vitamins and minerals

Deficiencies in nutrients, vitamins and minerals can include protein, fat soluble vitamins (A, D, E, K), vitamin B12, folate, iron, magnesium, zinc, and calcium. Protein deficiencies occur mainly due to increased bowel loss and the increased demands on inflammation and surgery. Fat-soluble vitamin deficiencies can be observed in the presence of steatorrhea (oily stools). Vitamin B12 deficiencies can occur following resection of the absorption site in the intestine. The causes of iron deficiency include malabsorption and blood loss. Magnesium and zinc deficiencies can be caused by diarrhea. Finally, calcium and vitamin D deficiencies can occur due to the interaction with medical treatment, especially with long-term use of corticosteroids.


Protein-energy malnutrition and nutritional deficiencies can cause various complications, such as weight loss, muscle wasting, anemia, osteoporosis and stunted growth in children.

Medical treatment

To date, there is no cure for Crohn's disease. Current treatment works to reduce inflammation and improve symptoms. It can include antidiarrheal drugs, corticosteroids, immunosuppressants, biologics, antibiotics, and sometimes surgery. This is because most people with Crohn's disease will need to be operated on. Surgery removes the sections of the intestine that are affected by the disease. This helps reduce symptoms, but does not cure disease, which may recur. Also, quitting smoking is strongly recommended since tobacco consumption increases the risk of recurrence. However, almost half of patients who have had an operation will need another one later. With the right treatment, most people can lead productive lives, but the disease is crippling in about 10% of cases.

Nutritional approach

The goal of the nutritional approach is to reduce symptoms, promote optimal nutritional status, promote clinical remission, prevent or delay symptoms, and prevent or correct growth retardation in children.

The nutritional approach is different depending on the stages of the disease. When the disease is in remission, the goal is to get the patient to eat a normal and balanced diet according to his tolerance. There is no special diet for Crohn's disease. Sometimes supplements may be needed, such as iron supplements in patients with chronic anemia. When the disease is relapsing and therefore active, it may be recommended to follow a diet restricted in fiber. Nutritional treatment may also include the use of enteral nutrition (tube feeding delivered directly into the stomach) to improve and maintain nutritional status. Finally, the use of parenteral nutrition (feeding administered intravenously) is rare, but may be necessary in very severe cases of the disease.


Crohn's disease has different complications. One of the complications of the disease is chronic malabsorption which can lead to the development of osteoporosis, especially in the presence of vitamin D and calcium deficiencies. Another complication is the increased risk of cancer in the sections of the intestine that are affected by the disease.

Future treatments

The main goal of current treatments for Crohn's disease is to control symptoms. With the emergence of personalized medicine in the treatment of Crohn's disease, therapies are also moving towards prevention of disability. Personalized medicine can be defined as the use of personalized treatments based on the genetic, clinical and environmental information of each individual. Using this medicine, models to predict the likely course of the disease are being developed. There are also a number of potential therapies currently under study, including several molecules taken orally. Finally, modifying the microbiota through food or other means could be beneficial and is also being studied.





Article written by:

Marie-Noël Marsan, Nutritionist

Maladies digestives

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