Crohn's disease — from causes to treatment and prevention options

Crohn’s disease (CD) is a chronic, idiopathic inflammatory disease of the gastrointestinal tract, which together with ulcerative colitis (UC) belongs to the group of idiopathic inflammatory bowel diseases (IBD – Inflammatory Bowel Disease). It is a progressive disease with a relapsing course that leads to damage to the bowel wall, the development of complications, and a significant reduction in patients’ quality of life. Despite intensive research, the etiology of the disease remains complex and only partly understood (Rogler et al., 2021).

In the last decades, a pronounced global rise in the incidence of CD has been observed, not only in regions with a high burden in Western Europe and North America, but also in countries in Central and Eastern Europe, Asia, Latin America, and Africa (Ng et al., 2017). This trend indicates that the etiopathogenesis of the disease involves not only genetic factors but also environmental and behavioral determinants related to a Western lifestyle—urbanization, changing dietary habits, reduced exposure to microorganisms, and changes in gut microbiota (Kaplan, Windsor, 2021).

According to available data, the prevalence of CD in Europe ranges between 100 and 300 cases per 100 000 inhabitants, while in Scandinavia (Sweden, Norway) it reaches as high as 350 cases per 100 000 inhabitants (Péntek et al., 2017). In North America, a similar range is reported, while in countries in Asia and Latin America, incidence is increasing dynamically, often by more than 5% per year (Ng et al., 2017). In Slovakia, according to data from the National Center of Health Information (NCZI, 2022), the number of patients with CD increased from about 1 500 in 2000 to more than 3 800 in 2020, representing a prevalence of 105–120 cases/100 000 inhabitants.

CD is most often diagnosed between 15 and 35 years of age, while a second smaller peak is observed at older age (Lakatos et al., 2023). The disease affects both sexes, men and women, although a slight predominance in women is observed (ratio 1,2:1) (Péntek et al., 2017).

Because of its chronic course, high prevalence, risk of complications, and economic burden of treatment, CD is a major public health issue. Its management requires a multidisciplinary approach involving gastroenterologists, surgeons, immunologists, dietitians, and psychologists (Turner et al., 2021).

The purpose of this work is to analyze available knowledge on CD from the perspective of etiopathogenesis, clinical course, diagnostic, and therapeutic options, with a focus on epidemiological trends worldwide and in Slovakia. At the same time, the article attempts to synthesize data from multiple professional sources to allow a comparative assessment of disease occurrence across regions.

Epidemiology, occurrence, prevalence, and incidence of Crohn’s disease

CD is among chronic noninfectious inflammatory bowel diseases with increasing prevalence mainly in middle- and high-income countries. It is now considered a growing public health problem due to its progressive character and high treatment costs (Lakatos et al., 2023).

Global trends

In the last decades, there has been a notable increase in the global occurrence of CD, with regional differences evident in the rate of growth. According to the systematic review by Ng et al. (2017), the incidence of CD in the 21st century ranges in Europe from 5 to 15 new cases annually per 100 000 inhabitants, with the highest values reported in Scandinavia, particularly Sweden (14,6/100 000) and Norway (13,5/100 000) (Péntek et al., 2017). In North America, incidence reaches up to 23,8/100 000 people per year, one of the highest values globally (Kaplan, Windsor, 2021).

In developed countries, the prevalence of IBD, and thus also the share of CD, is estimated at 300–380 cases per 100 000 inhabitants. In some countries (e.g., Canada, Denmark), prevalence approaches or exceeds 1% of the population (Kaplan, Windsor, 2021). As described by Ng et al. (2017), the highest reported prevalence of CD within Europe is in Germany (322/100 000), and the highest prevalence of UC is in Norway (505/100 000).

In developing countries and countries undergoing rapid industrialization, a faster pace of increase in this disease can be observed. Ng et al. (2017) report that in Brazil, CD incidence increased by 11,1% per year during 1988–2012, and in Taiwan, by about 4% per year during 1998–2008. This trend is supported by systematic analyses confirming that from 1990 onward, declining or stable incidences in the USA and Europe contrast with a steep rise in Latin America, Asia, and Africa (e.g., Brazil: 11,1% increase, Taiwan: 4,0% increase).

A population study in Norway conducted during 2010–2017 indicates one of the highest incidences of IBD worldwide. The incidence of CD in this period ranged between 14,1 and 16,0/100 000 people per year, and prevalence of CD in 2017 was estimated at 0,27% (0,27% for CD; 0,50% for UC). Multiple studies suggest that in Western regions there is a shift into a phase described as “compounding prevalence,” meaning that incidence begins to plateau or decline, while the number of people with the diagnosis continues to rise (due to low mortality and chronic disease) (Kaplan, Windsor, 2021; Sands et al., 2024).

An international analysis from the GIVES-21 project estimates that in Sweden the prevalence of IBD is around 1% of the population, meaning roughly one in one hundred people is affected. These data align with broader epidemiological trends described by Caron et al. (2014) in their review “Epidemiology of Inflammatory Bowel Disease across the Ages.” They report that in recent decades, CD incidence in Europe spans a wide range across countries, as does prevalence, which varies substantially between regions. Available epidemiological data also show marked geographic differences, with the highest CD incidence in North America, Canada, and Scandinavian countries, whereas lower values are typical for several Asian countries and some parts of Europe (Hracs et al., 2025). Figure 1 illustrates the incidence of CD in various countries and regions of the world. The data shown indicate pronounced geographic variation, with the highest incidence occurring in North America, Canada, and Scandinavian countries. Lower values are typical of Asian countries and some parts of Europe.

(Source: Author’s own processing according to Lirhus et al., 2021; Lördal et al., 2020; Burisch et al., 2013)

Epidemiology of Crohn’s disease in Slovakia

In Slovakia, there is currently no unified national IBD registry, so epidemiological data are derived from partial analyses, hospital data, and NCZI reports. These data show a gradual increase in disease occurrence in the Slovak Republic.

According to the National Center of Health Information data, the number of patients with CD approximately doubled between 2000 and 2020, from around 1 500 to more than 3 800 reported cases. This represents a prevalence of 105–120 cases per 100 000 inhabitants and an annual incidence of 8–12/100 000, comparable to countries in Central Europe (Lakatos et al., 2023).

This disease is most commonly diagnosed between 15 and 35 years of age. A mild predominance among women compared to men (ratio 1,2:1) is observed, and rising incidence is seen in children and adolescents (Péntek et al., 2017; Lakatos et al., 2023).

Regional differences in Slovakia

Regional data in the Slovak Republic are limited, but available partial studies suggest differences in incidence and prevalence by administrative area. In a historical study (up to 1994), CD incidence in former Czechoslovakia was estimated at 6,75/100 000 inhabitants, with no significant differences between regions but mild deviations between districts (Príkazská et al., 1996).

In the pediatric population (0–18 years) in Slovakia, incidence of 1,79–2,28/100 000 inhabitants and prevalence of 13,55/100 000 inhabitants were found in 2001–2003, with the highest prevalence recorded in the Bratislava region (Čierna et al., 2009).

Surgical data from 2015 report that 464 operations were performed at 19 Slovak centers for patients with IBD, of which 252 were abdominal surgeries and 140 were rectal surgeries in patients with CD. The highest numbers of operations were performed in Košice (n=43), Bratislava (n=25), and Martin (n=20) (Hlavatý, 2016). According to more recent media estimates (SITA, 2025), the number of patients with IBD in Slovakia is now around 28 000, with the assumption that some patients remain undiagnosed (SITA, 2025). Earlier TASR reports indicated approximately 4 500 patients with CD and an annual increase of about 400 new cases (SME, 2008).

Temporal trends and projections

Given the chronic nature of the disease and low mortality, the prevalence of CD continues to rise. Patients live with the disease for a long time, often for several decades, while newly diagnosed cases continue to accumulate. Model predictions indicate that in developed countries, CD prevalence may exceed 1% of the population within the coming decade (Kaplan, Windsor, 2021).

In Slovakia, a clear upward trend is evident, approaching the Western European average. The rise in pediatric cases and increasing numbers of surgical procedures indicate that CD is becoming a significant and steadily growing public health issue (Lakatos et al., 2023).

Etiology and pathophysiology of Crohn’s disease

CD is a multifactorial disease whose etiology is shaped by a complex interaction of genetic predisposition, defects in immune regulation, alterations in gut microbiome, and environmental factors. Despite advances in molecular biology and immunology, the exact mechanism of disease onset is not fully clarified, though several key factors contributing to development are known (Torres et al., 2017; Neurath, 2019).

Genetic factors play a major role in determining an individual’s susceptibility to CD. First-degree relatives of patients have up to ten times higher risk than the general population. Previous genetic studies have identified more than 230 loci associated with IBD, many of which are common to both CD and UC (Jostins et al., 2012; Liu et al., 2023). The most important mutations involve the NOD2/CARD15 gene, which encodes an intracellular receptor recognizing bacterial peptidoglycans. Defects in this gene lead to defective immune activation and insufficient elimination of bacteria from the gut environment, resulting in persistent inflammatory response. Mutations in ATG16L1 and IRGM, which regulate autophagy, affect the ability of cells to clear intracellular pathogens. Genes IL23R and TNFSF15 modulate T-lymphocyte differentiation and activation of inflammatory response (Jostins et al., 2012; Liu et al., 2023). These findings confirm that genetic susceptibility to CD is the result of combined action of multiple genes, each contributing modestly but significantly to total risk.

From an immunological perspective, CD is characterized by persistent activation of innate and adaptive immune responses. T-lymphocyte subtypes Th1 and Th17 play a dominant role, producing pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-α) and interleukins IL-1β, IL-6, IL-12, and IL-23. These mediators promote activation of macrophages, dendritic cells, and neutrophils, leading to prolonged inflammation and intestinal mucosal injury (Neurath, 2019). Increased expression of adhesion molecules (e.g., ICAM-1, MAdCAM-1) and chemokines (e.g., CXCL8, CCL20) mediates migration of immune cells into the intestinal wall. The result is transmural inflammation with granulomatous reaction and impaired epithelial regeneration. This pathophysiological mechanism explains the segmental pattern of bowel involvement typical of CD.

The gut microbiome is another key factor in etiopathogenesis. In CD patients, reduced gut microbial diversity is described, with reduction of beneficial bacteria (especially Faecalibacterium prausnitzii) and increased prevalence of adherent-invasive Escherichia coli strains (Ni et al., 2017). Dysbiosis disrupts gut barrier homeostasis, impairs short-chain fatty acid metabolism, and weakens anti-inflammatory mechanisms. This leads to increased epithelial permeability, allowing bacterial products to penetrate the submucosa and activate the immune system. Microbiome research opens new possibilities for intervention, such as probiotics, prebiotics, or fecal microbial transplantation, which could in the future complement conventional biologic treatment (D’Amico et al., 2022).

In addition to genetic and immunologic factors, environmental determinants have a considerable impact. CD occurs more often in urbanized areas among people with higher socioeconomic status and populations undergoing rapid urbanization. Among the major risk factors are smoking, which increases disease risk and accelerates progression, with more frequent relapses and later need for surgical intervention. In contrast, smoking has a paradoxical protective effect in patients with UC. Long-term antibiotic use in childhood, which disrupts physiological microbiota development, and diet high in saturated fats, animal proteins, and refined sugars that contribute to pro-inflammatory bowel activation are also risk factors (Ng et al., 2017; Kaplan & Windsor, 2021). The hygiene hypothesis suggests that lower microbial exposure in early life leads to insufficient immune tolerance development, increasing the risk of autoimmune and inflammatory diseases. Psychological factors may also play a role, especially stress, which modulates neuro-immune processes and contributes to disease flares (Turner et al., 2021).

Pathophysiologically, CD is characterized by segmental transmural inflammation affecting the entire thickness of the bowel wall and presenting as alternating inflamed and healthy bowel segments, known as skip lesions. Histological hallmark findings include necrosis and epithelioid granulomas in the submucosa and serosa. Long-term inflammation leads to progressive tissue fibrosis, strictures, fistulas, and abscesses. Chronic inflammatory activity also increases the risk of malignant transformation, especially adenocarcinoma of the small and large intestine (Torres et al., 2017).

Progress in molecular and immunological understanding has led to identification of multiple biomarkers and therapeutic targets. Current research investigates genetic and microbial signatures that allow individualized treatment approaches. A major modern aim is to create stratified therapeutic algorithms enabling early diagnosis and personalized treatment according to each patient’s immunogenetic profile (D’Amico et al., 2022; Liu et al., 2023).

Clinical presentation and complications of Crohn’s disease

The clinical presentation of CD is highly variable and depends on localization, extent, and activity of inflammation. The disease can affect any part of the gastrointestinal tract, most commonly the terminal ileum and the beginning of the colon. The most frequent symptoms are chronic diarrhea, abdominal pain, weight loss, fatigue, and general weakness. Due to the deep (transmural) nature of inflammation, complications such as intestinal strictures, abscesses, fistulas, and perianal lesions occur often; extraintestinal involvement of skin, eyes, joints, or liver is also not unusual (Pruthi et al., 2024).

The disease course is typically relapsing, with periods of relapse and remission. Diarrhea is often non-bloody, often accompanied by tenesmus and pain localized in the right lower quadrant of the abdomen. Some patients experience nausea, vomiting, anorexia, and malabsorption, leading to hypoproteinemia and deficiencies of vitamins and minerals (especially vitamin B12, folic acid, iron, and zinc). In 20–40% of cases, the disease manifests with perianal lesions, such as fissures, abscesses, or fistulas (Torres et al., 2017).

The clinical course can be divided into inflammatory, stricturing, and penetrating behavior types. The inflammatory type predominates in early stages and presents with diffuse mucosal inflammation without structural complications. The stricturing type is marked by progressive fibrosis and luminal narrowing, leading to subileal states and chronic obstruction. The penetrating type is associated with fistula and abscess formation that may communicate with other organs, the urinary bladder, vagina, or perianal skin (Satsangi et al., 2006; Torres et al., 2017).

CD complications are grouped into intestinal and extraintestinal categories. Intestinal complications include strictures, fistulas, perforations, abscesses, bleeding, and malignant transformation. Approximately 50% of patients require surgical intervention in the first ten years after diagnosis, and recurrence occurs after resection in more than 30% of cases (Lakatos et al., 2023). The most common reason for surgery is fibrotic stricture, ileocecal obstruction, or abscess complication. Surgery provides symptomatic relief but is not curative; recurrence at the anastomosis occurs in about 70% of patients within 10 years (Rieder et al., 2022).

In addition to intestinal complications, extraintestinal manifestations develop in 25–40% of patients and may precede bowel symptoms or appear during the disease course. The most common are musculoskeletal manifestations, such as peripheral arthritis and axial spondyloarthritis, which can be associated with bowel inflammation activity. Skin manifestations include erythema nodosum and pyoderma gangrenosum, with occurrence correlated to disease severity (Greuter, Vavricka, 2019). Ocular complications such as episcleritis and uveitis occur in about 5–10% of patients and are often associated with intestinal flare-ups. Hepatobiliary manifestations include hepatic steatosis, cholelithiasis, and primary sclerosing cholangitis, which is more frequent when CD is combined with UC (Torres et al., 2017). Less frequent are thromboembolic events, anemia of chronic disease, osteoporosis, and nutritional deficiencies, all contributing to increased morbidity.

The clinical course of CD is highly individualized and prognosis depends on timely diagnosis, response to treatment, and presence of complications. Chronic inflammation progressively causes structural changes in the bowel wall and irreversible gastrointestinal damage. Early intervention and monitoring of disease activity through biomarkers, endoscopy, or imaging are therefore essential to minimize complications and improve patient quality of life (Rieder et al., 2022; Lakatos et al., 2023).

Diagnosis of Crohn’s disease

Diagnosing CD is a complex process requiring a combination of clinical, laboratory, endoscopic, histological, and imaging examinations. The diagnostic aim is to confirm chronic inflammation, determine extent and localization of involvement, exclude other causes, and assess disease activity. Due to heterogeneous clinical presentation, no single specific test exists to confirm the diagnosis. Diagnosis is made through comprehensive clinical evaluation (Gomollón et al., 2017; Torres et al., 2017).

The first step is a detailed history focused on symptom duration, stool characteristics, abdominal pain, weight loss, family history, and extraintestinal manifestations. Physical examination is often non-specific but may reveal right lower quadrant tenderness, palpable resistance, or perianal lesions. Laboratory tests are used to assess inflammatory activity, nutritional state, and complications.

The most common laboratory markers include:

• C-reactive protein (CRP) – correlates with inflammatory activity and response to therapy,
• fecal calprotectin (FC) – a marker of gut inflammation with high sensitivity (up to 80–90%) and specificity for IBD, also useful for remission monitoring (Mosli et al., 2015),
• serum albumin and hemoglobin – evaluation of nutritional status and anemia,
• vitamin B12, iron, folic acid – monitoring malabsorptive complications,
• serologic markers (ASCA, pANCA) – supportive indicators in differential diagnosis between CD and UC (Clough et al., 2024).

A core diagnostic method for CD is endoscopy with histological sampling. Colonoscopy allows direct visualization of mucosal changes and biopsy from involved and uninvolved areas. Typical endoscopic findings include segmental inflammation, aphthous ulcers, deep linear ulcers, mucosal thickening, stenoses, and the characteristic “cobblestone appearance” of the bowel. Histology confirms diagnosis by demonstrating transmural inflammation, epithelioid granulomas, and fibrotic changes (Hong, Baek, 2024).

When the small intestine is involved and not accessible by conventional colonoscopy, enteroclysis, capsule endoscopy, or magnetic resonance (MRI) enterography are used. MRI enterography provides detailed imaging of bowel wall, mucosal ulcerations, abscesses, and fistulas without ionizing radiation exposure and is therefore preferred especially in younger patients (Kumar et al., 2024). In clinical practice, CT enterography is also used, which can visualize extraintestinal complications, though it is less suitable for repeated testing due to radiation burden.

Intestinal ultrasound (IUS) has a significant role as a non-invasive, accessible, repeatable method suited for assessing bowel wall thickness, vascularization, and presence of abscesses or fistulas (Maconi et al., 2018). This method has increasingly been used in recent years for activity monitoring and for decisions on treatment changes, especially in children and younger adults.

To assess CD activity, standardized scoring systems are used in clinical practice:

• Crohn’s Disease Activity Index (CDAI) – the most widely used tool combining clinical, laboratory, and subjective indicators;
• Harvey-Bradshaw index (HBI) – a simplified version of CDAI, suitable for routine clinical follow-up;
• Simple Endoscopic Score for Crohn’s Disease (SES-CD) – endoscopic assessment of mucosal severity;
• Magnetic Resonance Index of Activity (MaRIA) – an imaging score for MRI-based assessment of inflammatory activity (Kumar et al., 2024).

Differential diagnosis of CD includes distinguishing it from other inflammatory bowel diseases, infectious enterocolitides (e.g., Yersinia enterocolitica, Campylobacter jejuni, Mycobacterium tuberculosis), ischemic and post-radiation colitides, as well as celiac disease and malignancy. Correct interpretation of endoscopic, histologic, and laboratory findings is crucial for a correct diagnosis.

Over the last decade, diagnostic practice has moved toward a “treat-to-target” paradigm, emphasizing timely and precise diagnosis enabling early intervention and prevention of irreversible bowel damage (Turner et al., 2021). Within this strategy, a combination of non-invasive biomarkers, imaging, and endoscopy is recommended with the aim of achieving not only clinical but also mucosal remission.

Treatment of Crohn’s disease

Treatment of CD is focused on induction and maintenance of clinical and mucosal remission, prevention of complications, and improvement in quality of life. Because it is a chronic relapsing disease without curative pharmacotherapy, modern treatment strategies aim to control inflammation, prevent irreversible bowel-wall damage, and delay need for surgery. The modern treatment concept is based on the “treat-to-target” principle, emphasizing individualized management grounded in early diagnosis, regular activity monitoring, and timely treatment escalation based on objective parameters (Turner et al., 2021).

CD pharmacotherapy includes several major drug classes selected according to disease severity, disease location, associated complications, and prior response to therapy (Gomollón et al., 2017; Torres et al., 2017).

1. Aminosalicylates (5-ASA) Aminosalicylate drugs such as mesalazine or sulfasalazine have anti-inflammatory effects through inhibition of cyclooxygenase pathways and reduced prostaglandin production. Their effectiveness in CD is, however, limited, and they are mainly used in mild forms with colonic involvement. Studies have shown only minimal effect on induction of remission and no clear benefit for maintenance therapy (Veloso et al., 2021). Therefore, current recommendations consider 5-ASA an adjunctive therapy, and its use is mainly limited to patients with very mild disease course.
2. Corticosteroids Systemic corticosteroids (prednisolone, methylprednisolone) form the basis of induction therapy for moderate to severe CD. They act rapidly, suppressing inflammation by inhibiting pro-inflammatory cytokine production and reducing immune cell migration. They are primarily used during acute relapses but are not suitable for long-term use due to risk of serious adverse effects, such as osteoporosis, diabetes mellitus, hypertension, and mood disorders (Torres et al., 2017). A lower-systemic-exposure alternative is budesonide, suitable especially for patients with ileocecal disease localization.
3. Immunomodulatory treatment Immunomodulators such as azathioprine, 6-mercaptopurine, and methotrexate are used to maintain remission and reduce corticosteroid exposure. Their effect appears after several weeks to months and is based on suppression of T-lymphocyte proliferation and immune response modulation. Long-term therapy carries risks of hepatotoxicity, myelosuppression, and infections, requiring regular monitoring of hematologic and biochemical parameters (Gomollón et al., 2017). Immunomodulators are often combined with biologics to reduce immunogenicity and improve effectiveness (Velikova et al., 2024).
4. Biological treatment Biological drugs represent the most significant advance in CD therapy. They are monoclonal antibodies that specifically inhibit key cytokines or adhesion molecules involved in the inflammatory cascade. The most commonly used biologics include: - Anti-TNF-α antibodies – infliximab, adalimumab, certolizumab pegol: they effectively induce and maintain remission, promote mucosal healing, and reduce the need for surgery (Telli, Törűner, 2024). - Anti-integrins – vedolizumab, which blocks the α4β7 integrin, selectively inhibits migration of T-cells into intestinal mucosa, thereby minimizing systemic immunosuppressive effects (Feagan et al., 2016). - Anti-IL-12/23 drugs – ustekinumab, which inhibits the p40 subunit of interleukins IL-12 and IL-23, showing high efficacy in patients not responding to anti-TNF therapy (Feagan et al., 2016). A biologic treatment is considered effective when it not only leads to symptom relief but also to objective endoscopic mucosal healing. Treatment requires long-term administration and regular evaluation of efficacy and safety. The most common adverse events include infections, reactivation of latent tuberculosis, anti-drug antibody formation, and infusion reactions. In recent years, biosimilar agents have become more available, reducing treatment costs while maintaining equivalent efficacy.
5. New treatment modalities Clinical practice is increasingly adopting newer targeted molecules, such as Janus kinase (JAK) inhibitors and sphingosine-1-phosphate receptor (S1P) modulators. Tofacitinib, filgotinib, and ozanimod are promising therapeutic alternatives for patients who do not respond to conventional or biologic treatment. Their advantages include oral administration and rapid onset, though long-term safety remains under study (Sandborn et al., 2020).
6. Surgical treatment Surgery is indicated for patients with severe complications such as strictures, fistulas, abscesses, perforations, or failure of conservative therapy. The most common procedures are ileocecal resection or stricturoplasty. Despite technical advances, surgical treatment is not curative, as relapse occurs in 50–70% of patients within 10 years after resection (Rieder et al., 2022). Therefore, combined surgical and pharmacologic management and careful postoperative follow-up are essential.
7. Nutritional and supportive therapy Nutritional management is an integral part of CD treatment. In children, exclusive enteral nutrition can serve as primary induction therapy with efficacy comparable to corticosteroids, but without their adverse effects (Ruemmele et al., 2014). In adults, enteral or parenteral nutrition is mainly used as adjunctive support in malnutrition, before surgery, or during relapse. Important components of care also include vitamin (B12, D3, folic acid) and mineral (iron, calcium, zinc) supplementation, as well as psychological and educational support for patients.

CD treatment is now guided by an individualized approach considering disease phenotype, genetic and microbial factors, comorbidities, and patient preferences. A key trend over the past decade is a shift from reactive to proactive therapy, with emphasis on early treatment escalation and the use of biomarkers when deciding to change therapeutic strategy (Turner et al., 2021; Rieder et al., 2022).

Prevention of Crohn’s disease

Given the multifactorial etiopathogenesis, prevention is complex, and no method currently exists that can reliably prevent disease onset. Since CD is a chronic, genetically conditioned and environmentally influenced inflammatory condition, prevention strategies mainly focus on modifiable risk factors and early identification of high-risk individuals (Torres et al., 2017; Kaplan & Windsor, 2021). From a public health perspective, CD prevention can be considered at three levels: primary, secondary, and tertiary prevention, each with distinct goals and interventions.

Primary prevention Primary prevention is aimed at preventing disease onset in healthy individuals, mainly by influencing lifestyle, dietary habits, and exposure to risk factors. Although CD cannot be fully prevented, there are factors that markedly modify risk:

• Smoking – is the most important environmental risk factor for CD. Current smokers have approximately double the risk of disease development, a more severe course, higher relapse frequency, and greater need for surgical intervention compared with non-smokers (Mahid et al., 2006). Smoking cessation has a clearly documented positive effect on lowering disease activity and reducing relapse risk (Ng et al., 2017).
• Diet – a diet rich in fiber, fruit, vegetables, and omega-3 fatty acids lowers IBD risk, whereas high intake of saturated fats, red meat, food emulsifiers, and refined sugars increases risk (Ananthakrishnan, 2015). Consumption of fermented foods and probiotics has a favorable effect on the gut microbiota and may help prevent dysbiosis.
• Use of antibiotics in childhood – repeated or prolonged antibiotic therapy in early childhood is associated with higher CD risk, especially in genetically predisposed individuals (Hviid et al., 2011). Rational antibiotic use and support of natural microbial exposure may reduce risk.
• Breastfeeding – has a protective effect through support of gut microbiome development and immune tolerance. Meta-analyses confirm that breastfeeding lowers the risk of CD by about 30–40% (Xu et al., 2017).
• Early-life nutrition and the hygiene hypothesis – children raised in rural settings or with frequent microbial exposure have lower IBD risk, supporting the hypothesis that excessive hygiene and sterile environments may increase disease risk (Ng et al., 2017).

These findings suggest that preventive measures promoting healthy nutrition, non-smoking, limiting excessive antibiotic use, and supporting natural immune stimulation in early childhood may contribute to reduced CD incidence in the population.

Secondary prevention Secondary prevention focuses on early diagnosis and intervention in individuals whose disease is beginning to develop but has not yet caused irreversible bowel damage. In practice, this means actively identifying high-risk patients, such as relatives of people with IBD or individuals with persistent gastrointestinal symptoms.

Recommended steps include:

• Use of non-invasive biomarkers (e.g., fecal calprotectin, CRP),
• endoscopic examination when clinical suspicion is present,
• imaging methods (MRI enterography, intestinal ultrasound) to detect early inflammatory changes,
• early initiation of treatment, especially biological or immunomodulatory therapy, can prevent disease progression, lower complication risk, and reduce the need for surgery (Turner et al., 2021),
• The importance of secondary prevention also lies in educating primary care physicians and gastroenterologists so they can recognize early symptoms (e.g., chronic diarrhea, anemia, unexplained weight loss) and order appropriate investigations.

Tertiary prevention Tertiary prevention concerns patients with diagnosed CD and aims to prevent relapses, complications, and further progression. It focuses on long-term management, adherence to treatment, and lifestyle adjustment. Key elements include:

• adherence to pharmacotherapy – regular biological or immunomodulatory treatment under gastroenterologist supervision,
• smoking cessation and a healthy lifestyle,
• nutritional support and supplementation of vitamins and minerals,
• regular monitoring of disease activity (clinical, laboratory, endoscopic),
• prevention of infections and vaccination (e.g., hepatitis B, HPV, pneumococcal vaccines) before initiating immunosuppressive therapy (Gomollón et al., 2017),
• psychological and social support for patients, which clearly improves adherence and quality of life (Mikocka-Walus et al., 2016).
• Successful tertiary prevention requires a multidisciplinary approach involving close cooperation of a gastroenterologist, nutrition specialist, psychologist, and general practitioner. Modern strategies are centered on personalized management with emphasis on long-term maintenance of remission and minimizing therapeutic side effects.

Materials and methods

This work is a systematic literature review focused on meta-analytic synthesis of published estimates of incidence and prevalence of CD in Central Europe and comparable European regions. The goal was to assemble a current comparative overview for Slovakia, the Czech Republic, Hungary, Poland, Ukraine, and reference countries Germany/England (UK).

Source databases and search period. The search was conducted in PubMed/Medline, Embase, and Web of Science with a date range of 01/2019 – 10/2025; national and scientific professional databases (e.g., Crohn’s & Colitis UK/IBD Registry) and regional epidemiological journals were included. Search terms combined “Crohn’s disease”/“IBD” with “incidence,” “prevalence,” “population-based,” country names, and terms such as “registry,” “claims,” “national report.”

Inclusion criteria. Included were papers and reports providing quantitative, population-level estimates (per 100 000 persons/year for incidence, and per 100 000 inhabitants or % population for prevalence) published in 2019. National or regional population registries or representative administrative data were preferred; when a national estimate was unavailable, population-based cohorts (e.g., Veszprém, Hungary) with clearly defined catchment areas were accepted. Narrative reviews and global analyses were used only as supplementary context and for trend comparison.

Data extraction. Two independent reviewers extracted country/region, year of estimate, outcome definition, population size, and estimate itself (with 95% CI if reported). Where multiple estimates existed for the same period, the most representative and most recent source was prioritized. Discrepancies were resolved by consensus. Heterogeneity of methodologies (administrative data vs. registries vs. cohorts) was assessed qualitatively; because of source heterogeneity, no pooled effect was calculated, and a country-level comparative panel was prepared.

Primary outcomes. (i) CD prevalence per 100 000 inhabitants or in % population; (ii) CD incidence per 100 000 persons/year; (iii) brief qualitative characterization of the source (national report vs. registry cohort) and limitations. Where a CD-specific estimate was unavailable, IBD estimates with explicit notation were reported.

Results

Data availability and source types. For the countries under review, current (≤5 years) population estimates were obtained for Poland and the United Kingdom (UK/England); the Czech Republic has high-quality recent pediatric population data and multiple cohort outputs; Hungary has a long-term population cohort (Veszprém) with recent outputs; for Slovakia and Ukraine there is no recent national, peer-reviewed CD estimate in the last 5 years—administrative data (NCZI/MoH Slovakia; health insurers) and national registries should be added as they become available.

Overview of key numbers (last 5 years)

• Poland (national administrative data, 2020). CD prevalence: 60,3/100 000, UC: 187,8/100 000; total IBD ≈ 0,25% of population by 2020. The source reports 96 809 IBD patients (administratively identified).
• United Kingdom/England (Crohn’s & Colitis UK national report + University of Nottingham, 2020). UK CD prevalence: 0,31% (≈ 310/100 000); in the hospitalization-record subgroup for England 0,35% (≈ 350/100 000). The report summarizes incidence for 2000–2020 and prevalence for 2020.
• Czech Republic (pediatric population, nationwide/multi-regional network, 2020). Pediatric IBD incidence in 2020 is among the highest globally; long-term data show an upward trend with projection up to ~19/100 000/year for pediatric IBD by 2022; CD share ~5,2/100 000/year in older series (consistently rising trend). (Note: pediatric data are only partially comparable with adults.)
• Hungary (Veszprém province, population-based cohort of patients entering the study at diagnosis or treatment start, current outputs for years 2023–2025). The cohort provides population-referenced, long-term data on IBD including CD; recent publications focus on reoperation trends and disease behavior rather than new national incidence/prevalence estimates; it remains a representative regional model for Hungary with a long time series (2007–2018). The latest analyses from the Veszprém cohort report CD incidence in 2007–2018 at roughly 9,9 cases per 100 000 inhabitants per year. Disease prevalence was estimated at 236,8 cases per 100 000 inhabitants in 2015, indicating a substantial population burden and confirming a long-term upward trend in regional occurrence.
• Germany/Western Europe (contextual sources 2023–2024). Current reviews confirm Western Europe has among the highest CD prevalences, with values often >0,3% of population in some countries (e.g., Norway ~331/100 000; Scotland ~432/100 000 within the UK). (Note: a direct, very recent open-access German national CD estimate is less easily accessible within ≤5 years; reviews nevertheless place Germany among high-burden countries).
• Slovakia/Ukraine. No peer-reviewed national CD estimate with precise numbers has been published in the last 5 years; older Slovak studies and published IBD estimates (not strictly CD-only) are available. For analytical comparison, additional NCZI administrative counts and/or insurer data would be needed, with explicit separation of CD from UC.

Notes on comparability The UK and Poland are based on national data (2020), yielding high relevance and comparability. The Czech Republic (pediatrics) and Hungary (regional inception cohort) provide robust but not strictly national estimates (caution needed when comparing with adults/countries). Germany: high burden is consistently confirmed by reviews.

Discussion

Consistency of trends. Comparison over the last 5 years confirms that Central and Western Europe belong to regions with the highest CD prevalence. The UK (2020) reports CD prevalence around 0,31–0,35%, consistent with observations that overall IBD prevalence in Western European countries can exceed 0,5% of the population. In Poland (2020), national reports confirm 0,25% of the population with IBD and CD around 60/100 000, while UC is more common (≈188/100 000). This suggests that while Central Europe has lower CD prevalence than the UK/Scandinavia, the burden is clinically significant and rising.

Age and pediatric aspects. The Czech pediatric network indicates pediatric IBD incidence is globally among the highest, with a rising trend through 2020–2022, consistent with the shift toward younger age groups described in European reviews. In cross-national comparisons, however, pediatric versus adult indicators need to be distinguished.

Heterogeneity and methodological limitations. Comparability across countries is limited by: (i) different data sources (national registry vs. administrative insurance data vs. regional cohort), (ii) varying case definitions and observation periods, and (iii) incomplete capture of outpatient cases. This is why we intentionally avoided a pooled estimate and retained a country-level comparative panel. Contextual reviews from 2023–2024 consistently confirm that Western Europe has one of the highest burdens, while Central Europe (Poland, Czech Republic, Hungary, Slovakia) is converging upward, particularly in younger and pediatric populations.

Specifics of Slovakia/Hungary/Ukraine. For Slovakia and Ukraine, the main limitation is absence of a national peer-reviewed CD estimate; for Slovakia, administrative sources (NCZI) are available but do not always publish data distinguishing CD from UC in a comparable way. For Hungary, the Veszprém inception cohort offers a unique long-term view of the natural history of IBD, but remains regional (although methodologically strong).

Conclusion

Despite major progress in medicine, CD remains a complex disease that can significantly affect patients’ quality of life at any age. Its occurrence continues to rise in recent years and now affects regions where it was once rare, indicating a broader impact of modern lifestyle and changing environments. The disease is characterized by heterogeneous clinical presentation and variable progression, placing high demands on precise diagnosis and regular monitoring. Early recognition of inflammatory activity and potential complications is key to successful management.

Current therapeutic options allow targeted intervention in inflammatory mechanisms and can substantially improve prognosis for many patients. Modern treatment strategies are moving toward therapy individualization and emphasis on achieving deeper, not only symptomatic control. Nevertheless, patient education, adherence, and high-quality interdisciplinary collaboration remain essential parts of care.

In the future, personalized strategies that better account for genetic predisposition, the character of inflammatory response, and gut microbiome changes are expected to advance further. Such an approach opens space for more precise treatment targeting, reduced risk of complications, and long-term maintenance of disease stability. Even though CD remains a lifelong condition, a combination of modern diagnostics, advanced therapies, and comprehensive care allows patients to live a fuller life and better manage its challenges.

Authors: Mgr. Ján Roman Ústav verejného zdravotníctva a hygieny, UPJŠ LF v Košiciach prof. Mgr. MUDr. Erik Dorko, PhD., MPH, MBA Ústav verejného zdravotníctva a hygieny, UPJŠ LF v Košiciach Mgr. Anastasiia Ostafiichuk Ústav verejného zdravotníctva a hygieny, UPJŠ LF v Košiciach prof. MUDr. Kvetoslava Rimárová, CSc. Ústav verejného zdravotníctva a hygieny, UPJŠ LF v Košiciach doc. MUDr. Laura Gombošová, PhD. II. interná klinika UPJŠ LF a UNLP

This work was supported by grant projects of the Slovak Ministry of Education, Science, Research and Youth KEGA: project no. 001UPJŠ-4/2024 and no. 003UPJŠ-4/2024.

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