Author: Silvia Marinova, PhD student in the Genomic Stability Laboratory at BAS

Crohn's disease is a chronic recurrent inflammation of the gastrointestinal tract. It belongs to a group of conditions called inflammatory bowel diseases. The disease can affect the entire digestive system and cause symptoms such as diarrhea, serious weight loss, abdominal pain, general fatigue and others.

The clinical picture is very similar to ulcerative colitis, and this makes it difficult to differentiate them.

Both conditions can lead to serious consequences if not treated appropriately, and therefore their timely diagnosis is very important. In addition, for making a correct diagnosis, other disturbances of the gastrointestinal tract such as bacterial infections must first be distinguished and excluded.


Who is at higher risk of Crohn's disease

The disease develops with the same frequency in men and women, most often in late adolescence or early adulthood, usually between the ages of 15 and 30 years of age [ref.1]. However, there is also a second age peak of disease: between the ages of 55 and 59 years of age [ref.2]. Crohn's disease also has a genetic burden and therefore there is an increased risk of developing the disease if your relatives suffer from it.

Besides genetic predisposition, other risk factors [ref.3] predisposing to the development of the disease are considered disorders in the intestinal flora (dysbiosis), infections of the digestive system, the use of antibiotics at an early age, smoking, etc.


Symptoms of Crohn's disease

Crohn's disease is a chronic inflammatory disease, which means that periods of remission alternate with periods of exacerbation, characterized by a pronounced symptomatology. Unlike ulcerative colitis, it can affect different parts of the entire digestive tract.

Most often it is the small or large intestine, but sometimes the duodenum or stomach may be affected. For this reason, the clinical picture may have personal differences, but nevertheless there are some common symptoms of gastrointestinal inflammation, which can also be caused by Crohn's disease. These are:

  • abdominal pain

  • diarrhoea or constipation

  • unexplained increase in temperature

  • general tiredness and fatigue

  • weight loss

  • frequent occurrence of sores

  • delayed development and growth in children

  • skin irritations, etc.

In case of suspected Crohn's disease or manifestation of some of the above symptoms, consultation with a doctor is necessary, since the disease has a serious prognosis and can lead to dangerous complications.


What are the complications of Crohn's disease

If it remains undiagnosed or is not treated promptly and adequately, Crohn's disease can have serious consequences. [ref.4]

An example of such complications are:

  • Obstruction of the intestine - this term means narrowing of the opening of the intestine caused by thickening of its wall. It can lead to blockage.

  • Fistula - is an abnormal duct that can form between one part of the intestine and another as a result of inflammation. It is removed operationally.

  • Fissure - rupture of the most superficial layer (mucous membrane) of the anus, which is highly painful and often leads to bleeding or leakage of another secretion, imbling with pus.

Patients suffering from Crohn's disease have an increased risk of developing cancer and frequent monitoring by a doctor is necessary.


How is Crohn's disease diagnosed

As already mentioned, the disease is difficult to diagnose, since the symptoms vary from person to person and are also very similar to those of a number of other diseases of the digestive system.

There are different approaches to the detection of the disease, and it will most likely be necessary to carry out a combination of tests to confirm its presence. This usually involves combining a general physical examination with laboratory tests, endoscopy and / or imaging techniques at the discretion of the gastroenterologist.

Laboratory tests

  • Blood test - usually checked whether the patient is anemic or has inflammation. It is good to know that if the results are negative, this does not exclude Crohn's disease as a possible diagnosis.

  • Fecal test to detect the presence of blood.

Endoscopic research

They are the gold standard in the diagnosis of Crohn's disease, because they allow the detailed looking of parts of the gastrointestinal tract for pathological changes. For this purpose, a small camera is used, which is inserted on top of a thin hose. Endoscopic studies are:

  • Gastroscopy - allows a view of the upper part of the digestive system - esophagus, stomach and duodenum.

  • Colonoscopy - allows a view of the large and lower end of the small intestine.

  • Capsule endoscopy - allows a view of the small intestine. The patient swallows a capsule in which there is a small chamber and naturally it reaches the small intestine, which is not accessible by the other two described endoscopic methods.

Sometimes in endoscopic examination, a biopsy is taken from some parts of the digestive tract at the discretion of the doctor. The aim is histological examination of the tissues taken for pathologies.


In more severe cases where there are complications, it is often necessary to use diagnostic imaging methods. Such are MRI, computed tomography (CT), as well as ultrasound. MRI and CT scans may show the severity of complications such as fistulas. In contrast, ultrasound is used mainly in emergencies [ref. 5], when rapid diagnosis is required.


Conventional treatment of Crohn's disease

Treatment of the disease depends on its severity, as well as which part of the digestive system it affects. There are various medical therapies that relieve symptoms and allow patients to control the disease, but unfortunately no treatment is available that leads to complete recovery. Surgery is often required to remove the damaged parts. Some patients require more than one operation [ref. 6].

Treatment with pills aims to suppress inflammation. This not only leads to relief of symptoms, but also allows the affected tissues to recover. Proper therapy aims to increase the periods of remission of the disease at the expense of reducing acute phases.

As with all diseases of the digestive system, an important part of controlling the disease is also compliance with an appropriate diet. It is good to avoid irritating foods that cause increased symptoms and discomfort. Such are foods rich in fiber, flavored with strong spices or chillies. The diet to be followed is also individual and it is good to be prepared by a specialist.


Genetic factors contributing to Crohn's disease

The causes of Crohn's disease are complex. This condition is the result of a combination of genetic factors, environmental factors and lifestyle, many of which are unknown.

Many of the main genes associated with Crohn's disease, including NOD2, ATG16L1, IL23R and IRGM, are involved in the function of the immune system. Proteins produced by these genes help the immune system to adequately recognize and respond to bacteria on the lining of the digestive tract. Many of the proteins play a role in autophagy, a process that cells use to destroy bacteria and viruses. Variations in these genes can disrupt autophagy or otherwise alter the immune system's response to bacteria in the digestive system. In combination with other genetic and environmental factors, these changes can lead to chronic inflammation and lead to digestive problems characteristic of Crohn's disease.

Researchers have identified at least 200 genetic variations that affect the risk of Crohn's disease. Most of these variants are thought to work by fine-tuning the amount, timing and location of gene activity (expression). The mechanism by which many variants affect disease risk is unknown - although they probably alter the function of the immune system in some way. Taken together, the known genetic variations represent only a small percentage of the overall risk of Crohn's disease due to genetic factors.

Other genes known to be relevant for the development of Crohn's disease are: HLA-DRB1, IL10, IL12B, JAK2, LRRK2, MUC2, SLC22A4, SLC22A5, STAT3, TYK2. [ref. 7]


Herbs that may help Crohn's disease sufferers

There are few studies on the effects of herbs on improving symptoms of Crohn's disease. However, several stand out, which can bring relief to both sufferers in the active stage of the disease and help retain at the stage of remission. [ref.8]

For patients in an active form of the disease, those herbs are promising:

  • Boswellia serrata H5 extract (Indian incense is made of it);
  • mastic resin from the Mastic tree (Pistacia lentiscus);
  • wormwood (Artemisia absinthium) - also known as grand wormwood, absinthe, absinthium, absinthe wormwood, mugwort, wermout, wermud, wormit, wormod;
  • Tripterygium wilfordii - a herb used in Chinese traditional medicine.

To maintain remission:

  • Boswellia plant extract (Boswellia serrata);
  • léi gōng téng (Tripterygium wilfordii) also known as thunder god vine but more properly translated as thunder duke vine.

Of course, before taking any of these herbs, be sure to consult your attending physician - each case is individual and should be considered by a specialist!



  1. At what age does the onset of Crohn disease typically occur?
  2. Association of age at diagnosis and Crohn's disease phenotype. Age Ageing. 2013
  3. Crohn Disease: Epidemiology, Diagnosis, and Management.
  4. Scientific publications on complications of Crohn's disease
  5. Diagnosis and management of Crohn's disease. J Ultrasound. 2015
  6. Hospitalisations and surgery in Crohn's disease. Gut. 2012
  8. Herbal and plant therapy in patients with inflammatory bowel disease. Ann Gastroenterol. 2015


The author:

👩 🔬 Silvia Marinova has a BSc in Molecular biology (Sofia University, Bulgaria), and a MSc in structural biology (Grenoble, France). She is currently a doctoral student at the Laboratory of Genomic Stability at IMB, BAS. Her research interests are in the field of DNA repair, microscopy and biophysics. She loves photography, painting and sports.