Phenotypic characteristics of pediatric inflammatory bowel disease in Japan: results from a multicenter registry

Prevalence of Inflammatory Bowel Disease Unclassified, as Estimated Using the Revised Porto Criteria, among Korean Pediatric Patients with Inflammatory Bowel Disease

Purpose

Few studies have reported the prevalence of inflammatory bowel disease unclassified (IBDU) among Korean pediatric IBD (PIBD) population. To address this gap, we used two tertiary centers and nationwide population-based healthcare administrative data to estimate the prevalence of Korean pediatric IBDU at the time of diagnosis.

Methods

We identified 136 patients aged 2-17 years with newly diagnosed IBD (94 Crohn's disease [CD] and 42 ulcerative colitis [UC]) from two tertiary centers in Korea between 2005 and 2017. We reclassified these 136 patients using the revised Porto criteria. To estimate the population-based prevalence, we analyzed Korean administrative healthcare data between 2005 and 2016, which revealed 3,650 IBD patients, including 2,538 CD and 1,112 UC. By extrapolating the reclassified results to a population-based dataset, we estimated the prevalence of PIBD subtypes.

Results

Among the 94 CD, the original diagnosis remained unchanged in 93 (98.9%), while the diagnosis of one (1.1%) patient was changed to IBDU. Among the 42 UC, the original diagnosis remained unchanged in 13 (31.0%), while the diagnoses in 11 (26.2%), 17 (40.5%), and one (2.4%) patient changed to atypical UC, IBDU, and CD, respectively. The estimated prevalences of CD, UC, atypical UC, and IBDU in the Korean population were 69.5%, 9.4%, 8.0%, and 13.1%, respectively.

Conclusion

This study is the first in Korea to estimate the prevalence of pediatric IBDU. This prevalence (13.1%) aligns with findings from Western studies. Large-scale prospective multicenter studies on PIBDU are required to examine the clinical features and outcomes of this condition.

Prognosis of pediatric ulcerative colitis after infliximab failure: A multicenter registry-based cohort study

BACKGROUND AND AIM

Even with increasing numbers of biologic agents available for management of ulcerative colitis (UC), infliximab (IFX) retains an important place in treatment of pediatric patients with this disease. As few reports have addressed outcomes in pediatric UC patients who had to discontinue IFX, we examined clinical course and prognosis after IFX failure in pediatric UC.

METHODS

A prospective cohort study of pertinent cases enrolled in the Japanese Pediatric Inflammatory Bowel Disease Registry between 2012 and 2020 was conducted to determine outcomes for pediatric UC patients who received IFX but required its discontinuation during follow-up (IFX failure).

RESULTS

Of the 301 pediatric UC patients in the registry, 75 were treated with IFX; in 36 of these, IFX was discontinued during follow-up. Severity of UC at onset and absence of concomitant immunomodulator therapy were significant risk factors for IFX failure (P = 0.005 and P = 0.02, respectively). The cumulative colectomy rate after IFX failure was 41.3% at 1 year and 47.5% at 2 years. Colectomy was significantly more frequent when IFX was discontinued before June 1, 2018, than when IFX was discontinued later (P = 0.013). This difference likely involves availability of additional biologic agents for treatment of UC beginning in mid-2018 (P = 0.005).

CONCLUSION

In pediatric UC patients, approximately 50% underwent colectomy during a 2-year interval following IFX failure. Prognosis after IFX failure appeared to improve with availability of new biologic agents and small-molecule drugs in mid-2018.

Clinical and therapeutic characterisation of a multicentre cohort of patients with inflammatory bowel disease in Colombia

INTRODUCTION

In Latin America and Colombia there are few studies about the clinical and therapeutic characteristics of patients with inflammatory bowel disease (IBD). The objective of this study is to obtain an approximation to these data from a sample of patients from different reference centres in Colombia.

PATIENTS AND METHODS

Cross-sectional study in adult and paediatric patients, with IBD, attended ambulatory in 6 institutions in different cities, between 2017 and 2020 information was collected on different dates, about demographic, clinical, and therapeutic aspects.

RESULTS

Six hundred and five subjects, 565 (93.4%) adults, mean age 43 years (SD 12.78), 64% with ulcerative colitis (UC). The age at diagnosis of UC was 41.9 years, while in Crohn's disease (CD) it was 47.9 years. In UC, there was greater left involvement (47.2%), and in CD, 42.8% ileocolonic (L3). More than 50% were in mild activity or clinical remission. In UC, the biologic requirement was 27.2%, while in CD, 78%. Overall hospitalisation requirement was 39.5%, and the need for surgery was 37.5% in UC and 62.5% in CD. Also, 40 pediatric patients, 90% female, with UC being more frequent (80%). In UC, 83.3% presented extensive colitis, and in CD, all with ileocolonic localization (L3). More than 95% were in mild activity or remission. Biologic therapy was required in 16.6% and 75% for UC and CD, respectively. The frequency of hospitalisations and surgery was 2.7%.

CONCLUSIONS

This study shows some unique characteristics of patients with IBD in Colombia. An earlier diagnosis is required, with a better therapeutic approach.

Comparison of Clinical Outcomes in Pediatric Patients with Ileocolonic Crohn Disease Treated with Infliximab Versus Adalimumab

OBJECTIVES

Infliximab is considered superior to adalimumab in patients with ulcerative colitis, especially in severe cases. Whether this is true for Crohn disease (CD) patients with colonic involvement is unclear. Our aim was to compare the clinical effectiveness of infliximab versus adalimumab in pediatric ileocolonic (L3) CD.

METHODS

This retrospective study included patients <18 years with ileocolonic CD treated with infliximab or adalimumab between 2014 and 2021. Primary outcome was steroid-free clinical remission by week 52. Secondary outcomes were treatment modifications, drug discontinuation, inflammatory bowel disease (IBD)-associated hospitalizations, and surgery during the first year of treatment.

RESULTS

We identified 74 patients treated with adalimumab and 41 with infliximab, with comparable demographic features. Concomitant immunomodulator therapy at biologic initiation was significantly lower in the adalimumab group (28% vs 85%, P < 0.001). Rates of drug intensification were higher in the infliximab group at end of induction (EOI) and at 52 weeks (55% vs 32% and 88% vs 46%, P < 0.001). Given significant differences between initial median Pediatric Crohn Disease Activity Index scores (20.0 [interquartile range, IQR 15.0-27.5] vs 11.0 [IQR 7.5-20.0] for infliximab and adalimumab groups, respectively, P < 0.001), propensity score matching was performed. Following matching, the rate of patients in steroid-free clinical remission by EOI was significantly higher in the adalimumab group (93.8% vs 46.9%, P < 0.001), but comparable by 1 year. Moreover, inflammatory markers and fecal calprotectin values were also similar at these time points. Rates of drug discontinuation, IBD-associated admissions, and surgery were similar between groups.

CONCLUSIONS

In a retrospective study of patients with ileocolonic CD, adalimumab and infliximab had comparable outcomes by 52 weeks.

Clinical characteristics and nursing diagnoses of pediatric patients hospitalized with inflammatory bowel disease: a single-center retrospective study in South Korea

PURPOSE

This study aimed to identify clinical characteristics of South Korean pediatric inflammatory bowel disease (IBD) in a children's hospital over the past 5 years, with a specific focus on comparing the features observed between Crohn's disease (CD) and ulcerative colitis (UC). Additionally, it aimed to examine the nursing diagnoses given to patients.

METHODS

This retrospective study analyzed the medical records of Korean pediatric patients under 18 years of age who were diagnosed with IBD and hospitalized at a children's hospital in Seoul, South Korea, from January 2017 to December 2021.

RESULTS

The number of pediatric patients diagnosed with IBD steadily increased. This finding was particularly prominent for CD patients, the majority of whom were male. Pediatric patients with CD had significantly higher rates of abdominal pain and perianal lesions, while pediatric patients with UC had a higher rate of bloody stool. Laboratory findings indicated that CD patients had higher levels of inflammatory markers and lower albumin levels than UC patients. The nursing diagnoses given during hospitalization mostly related to safety and protection, physical comfort, and gastrointestinal function.

CONCLUSION

This study provides insights into Korean pediatric IBD patients, enabling early detection and the development of nursing intervention strategies. From a comprehensive perspective, nursing care should not only address patients' physical needs but also their psychosocial needs.

Clinical outcome of ulcerative colitis with severe onset in children: a multicenter prospective cohort study

BACKGROUND

As best practices for treating children with severe-onset ulcerative colitis remain controversial in the era of biologic agents, we prospectively investigated treatments and outcomes in a multicenter cohort.

METHODS

Using a Web-based data registry maintained in Japan between October 2012 and March 2020, we compared management and treatment outcomes in an S1 group defined by a Pediatric Ulcerative Colitis Activity Index of 65 or more points at diagnosis with those in an S0 group defined by an index value below 65.

RESULTS

Three hundred one children with ulcerative colitis treated at 21 institutions were included, with follow-up for 3.6 ± 1.9 years. Among them, 75 (25.0%) were in S1; their age at diagnosis was 12.3 ± 2.9 years, and 93% had pancolitis. Colectomy free rates in S1 were 89% after 1 year, 79% after 2, and 74% after 5, significantly lower than for S0 (P = 0.0003). Calcineurin inhibitors and biologic agents, respectively, were given to 53% and 56% of S1 patients, significantly more than for S0 patients (P < 0.0001). Among S1 patients treated with calcineurin inhibitors when steroids failed, 23% required neither biologic agents nor colectomy, similarly to the S0 group (P = 0.46).

CONCLUSIONS

Children with severe ulcerative colitis are likely to require powerful agents such as calcineurin inhibitors and biologic agents; sometimes colectomy ultimately proves necessary. Need for biologic agents in steroid-resistant patients might be reduced to an extent by interposing a therapeutic trial of CI rather than turning to biologic agents or colectomy immediately.

Potential of Gut Microbe-Derived Extracellular Vesicles to Differentiate Inflammatory Bowel Disease Patients from Healthy Controls

Background/Aims

This study aimed to evaluate the potential of the stool microbiome and gut microbe-derived extracellular vesicles (EVs) to differentiate between patients with inflammatory bowel disease (IBD) and healthy controls, and to predict relapse in patients with IBD.

Methods

Metagenomic profiling of the microbiome and bacterial EVs in stool samples of controls (n=110) and patients with IBD (n=110) was performed using 16S rRNA sequencing and then compared. Patients with IBD were divided into two enterotypes based on their microbiome, and the cumulative risk of relapse was evaluated.

Results

There was a significant difference in the composition of the stool microbiome and gut microbe-derived EVs between patients with IBD and controls. The alpha diversity of the microbiome in patients with IBD was significantly lower than that in controls, while the beta diversity also differed significantly between the two groups. These findings were more prominent in gut microbe-derived EVs than in the stool microbiome. The survival curve tended to be different for enterotypes based on the gut microbe-derived EVs; however, this difference was not statistically significant (log-rank test, p=0.166). In the multivariable analysis, elevated fecal calprotectin (>250 mg/kg) was the only significant risk factor associated with relapse (adjusted hazard ratio, 3.147; 95% confidence interval, 1.545 to 6.408; p=0.002).

Conclusions

Analysis of gut microbe-derived EVs is better at differentiating patients with IBD from healthy controls than stool microbiome analysis.

Medical Management of Pediatric Inflammatory Bowel Disease (PIBD) in the Asia Pacific Region: A Position Paper by the Asian Pan-Pacific Society for Pediatric Gastroenterology, Hepatology, and Nutrition (APPSPGHAN) PIBD Working Group

Pediatric inflammatory bowel disease (PIBD) is rising rapidly in many industrialised and affluent areas in the Asia Pacific region. Current available guidelines, mainly from Europe and North America, may not be completely applicable to clinicians caring for children with PIBD in this region due to differences in disease characteristics and regional resources constraints. This position paper is an initiative from the Asian Pan-Pacific Society for Pediatric Gastroenterology, Hepatology and Nutrition (APPSPGHAN) with the aim of providing an up-to-date, evidence-based approach to PIBD in the Asia Pacific region, taking into consideration the unique disease characteristics and financial resources available in this region. A group of pediatric gastroenterologists with special interest in PIBD performed an extensive literature search covering epidemiology, disease characteristics and natural history, management and monitoring. Gastrointestinal infections, including tuberculosis, need to be excluded before diagnosing IBD. In some populations in Asia, the Nudix Hydrolase 15 (NUD15) gene is a better predictor of leukopenia induced by azathioprine than thiopurine-S-methyltransferase (TPMT). The main considerations in the use of biologics in the Asia Pacific region are high cost, ease of access, and potential infectious risk, especially tuberculosis. Conclusion: This position paper provides a useful guide to clinicians in the medical management of children with PIBD in the Asia Pacific region.

SYSTEMATIC REVIEW AND META - ANALYSIS OF THE FREQUENCY AND RE-CLASSIFICATION TRENDS OF PEDIATRIC INFLAMMATORY BOWEL DISEASE - UNCLASSIFIED

BACKGROUND

The term inflammatory bowel disease-unclassified (IBDU) is used when an individual has chronic colitis but cannot be sub-typed into ulcerative colitis (UC) or Crohn's disease (CD) on the basis of the clinical, endoscopic, imaging and histopathological features. On follow-up a proportion of patients with IBDU are re-classified as CD or UC. There has been considerable variability in the frequency and reclassification rates of pediatric IBDU in published literature.

METHODS

PubMed and Scopus and were searched for publications related to Pediatric Inflammatory Bowel Disease (PIBD) published between Jan,2014 and July,2021. Two reviewers independently searched and selected studies reporting the frequency of IBDU and/or their re-classification. The pooled prevalence was expressed as proportion and 95%CI. Meta-analysis was performed using the inverse variance heterogeneity model.

RESULTS

A total of 2750 studies were identified through a systematic search of which 27 studies were included in this systematic review. The overall pooled frequency of IBDU (n=16064) was found to be 7.1% (95%CI 5.8-8.5%). There was no variation in IBDU frequency by geographical location. Seven studies (n=5880) were included in the IBDU re-classification analysis. Overall, 50% (95%CI 41-60%) children with IBDU were re-classified on follow-up. Amongst these 32.7% (95% 21-44%) were re-classified to UC and 17% (95%CI 12-22%) were re-classified to CD.

CONCLUSION

IBDU comprises 7.1% of PIBD at initial diagnosis. Half of these children are re-classified into UC or CD on follow-up with a higher likelihood of re-classification to UC as compared to CD.

Phenotypic Pattern of Early Versus Later-Onset Pediatric Inflammatory Bowel Disease in a Eurasian Country

OBJECTIVES

It is not clear whether the characteristics of pediatric inflammatory bowel disease (IBD) differ between Eastern and Western countries. The aim of this study was to analyze the characteristics of PIBD in Turkey, according to the age at diagnosis.

METHODS

The data of 176 children with IBD who were followed in our center were analyzed. Patients were divided into early (EO-IBD, onset at 2 to &lt;10 years) and later-onset (LO-IBD, 10 to ≤17 years) IBD according to the age at diagnosis. Patients' data with ulcerative colitis (UC) and Crohn's disease (CD) were compared.

RESULTS

Of 176 patients, 47 (26.7%) were diagnosed with EO-IBD. Patients with early-onset ulcerative colitis (EO-UC) had the highest rate of family history of IBD (17.6%). Pancolitis was the most common form of UC regardless of the age at onset. The rate of moderate-severe disease activity in later-onset UC (62.5%) was higher than in EO-UC (37.5%). A higher rate of extraintestinal manifestations was observed in EO-IBD patients, particularly in EO-UC (38.2%) than in LO-IBD patients. Patients with early-onset CD (EO-CD) had predominantly colonic involvement and nonstricturing, nonpenetrating disease behavior. The rate of perianal disease in patients with later-onset CD (LO-CD) (64.5%) was noticeably higher than those with EO-CD (23%).

CONCLUSIONS

Our results suggest that patients with EO-UC represented a distinct phenotype with a mild disease activity, high rate of extraintestinal symptoms, and a high proportion of family history. The analysis of our IBD cohort also demonstrated remarkably high rate of perianal disease, particularly in patients with LO-CD.

Personalized medicine in inflammatory bowel disease: Perspectives on Asia

Inflammatory bowel diseases are chronic, relapsing inflammatory disorders of the gastrointestinal tract with variable disease courses and complications, which in some cases can result in significant morbidities and disabilities. Etiologies remain unclear due to complex interactions between genetic and environmental factors. Considering the heterogeneity of inflammatory bowel diseases, personalized approaches in diagnosing and managing affected patients would be beneficial in maximizing treatment efficacies and minimizing adverse events. Personalized medicine may also help to stratify patients with a high risk of progression and inflammatory bowel disease-related complications and identify sub-phenotypic mechanisms to facilitate drug discovery and the development of new treatments. In Asia, with a rapidly increasing incidence and prevalence of inflammatory bowel diseases, studies have shown that patients of Asian ethnicity differ from their Western counterparts in terms of genetic and clinical aspects of inflammatory bowel diseases. Therefore, personalized medicine may differ for patients of Asian ethnicity with inflammatory bowel diseases. We reviewed and summarized current evidence concerning personalized medicine for the diagnosis and management of patients with inflammatory bowel diseases and its possible role from an Asian perspective.

Symptom Improvement of ulceRative colitis after an Induction dose of UStekinumab in Japanese clinical practice (SIRIUS), measured using patient-reported outcomes: a prospective observational study

INTRODUCTION

Ulcerative colitis (UC) is an idiopathic, chronic inflammatory disease of the large intestine. Ustekinumab is a monoclonal antibody against the p40 subunit of interleukin-12 and interleukin-23 and has proven efficacy in inducing and maintaining remission in adult patients with moderate-to-severe UC. In the Symptom Improvement of ulceRative colitis after an Induction dose of Ustekinumab study, we will document the initial treatment response (daily patient-reported outcomes for 8 weeks from first infusion) and treatment patterns of patients wih UC receiving an induction dose of ustekinumab in the real-world setting in Japan. We will also investigate the relationship between the treatment response at week 8 and early indicators of response and determine patient factors that may define the appropriate dosing interval for maintenance therapy.

METHODS AND ANALYSIS

For this single-arm, prospective observational study at 24 centres in Japan with a follow-up period of 16/20 weeks, we aim to recruit 140 patients with moderate-to-severe UC between July 2021 and July 2022. All surveys will be conducted in Japanese and patient-reported outcomes relating to rectal bleeding, stool frequency, abdominal pain, nocturnal diarrhoea, tenesmus and perception of UC symptoms will be recorded using a smartphone application, where the patients can enter their initial response to ustekinumab induction therapy on a daily basis. Dosing intervals and the reasons for selecting this interval, and concomitant medications taken during treatment with ustekinumab will be collected by a physician questionnaire at the end of the study. On completion of primary end point (8-week patient-reported outcomes) data collection, results will be reported sequentially.

ETHICS AND DISSEMINATION

The study has been approved by the ethics committee of each facility involved and the Institutional Review Board of the non-profit organisation MINS.

TRIAL REGISTRATION NUMBER

UMIN000043753, NCT04963725.

Clinical Features and Long-Term Outcomes of Paediatric-Onset Inflammatory Bowel Disease in a Population-Based Cohort in the Songpa-Kangdong District of Seoul, Korea

BACKGROUND AND AIMS

The long-term outcomes of paediatric-onset inflammatory bowel disease [pIBD] in non-Caucasian populations are unknown. We therefore evaluated and compared the clinical features and long-term outcomes of pIBD with those of adult-onset IBD [aIBD] using a population-based cohort in the Songpa-Kangdong district of Seoul, Korea.

METHODS

Clinical characteristics and prognoses were compared between the two groups: pIBD [defined as <18 years of age at diagnosis] and aIBD [18-59 years of age at diagnosis].

RESULTS

We identified 131 patients with pIBD (48 ulcerative colitis [UC], 83 Crohn's disease [CD]) and 1192 patients with aIBD [866 UC, 326 CD] during 1986-2015. Extensive colitis at diagnosis was more prevalent in pUC than in aUC [45.8% vs 22.3%, p < 0.001], and the overall exposure to corticosteroids, thiopurines and anti-tumour necrosis factor agents was higher in pUC than in aUC [p < 0.001]. The cumulative risk of colectomy was higher in pUC than in aUC during a median follow-up of 125.0 and 112.1 months, respectively [8.9% vs 1.8% at 10 years after diagnosis, p = 0.030]. Ileocolonic location and inflammatory behaviour at diagnosis were more common in pCD than in aCD; however, patients with pCD and aCD did not differ regarding treatment or disease course during a median follow-up of 137.2 and 120.9 months, respectively.

CONCLUSION

Our study showed clear differences between pIBD and aIBD, especially in UC. pUC presents with more extensive diseases and may have a more severe disease course, as suggested by an earlier time to administering medications and performing colectomy.

Incidentally Detected Asymptomatic Perianal Abscess in an Adolescent during Crohn's Disease Diagnosis: Is Routine Pelvic Imaging Required in Korean Pediatric Patients at Diagnosis?

Perianal fistulizing diseases, namely perianal fistulas and/or abscesses, are well-known complications of Crohn's disease (CD). These are known to develop more frequently in Asian children with CD, especially in the early stages of the disease course. Approximately half of the pediatric CD cases in Korea present with perianal fistulizing diseases at diagnosis. We report a rare case of a 12-year-old boy with CD with an incidental discovery of a perianal abscess on pelvic magnetic resonance imaging during CD diagnosis. No symptoms or signs of perianal fistulizing disease were identified. The early diagnosis of the perianal abscess enabled timely and effective treatment. Considering the high incidence of concomitant perianal CD in Korean children at diagnosis, perianal imaging may be useful and should be considered during diagnostic evaluation, even in patients with no subjective or objective findings indicating perianal CD.

Very early onset inflammatory bowel disease in a South Asian country where inflammatory bowel disease is emerging: a distinct clinical phenotype from later onset disease

BACKGROUND/AIMS

Information on pediatric inflammatory bowel disease (PIBD) and very early onset IBD (VEOIBD) are sparse in India, where IBD is emerging. We aimed to evaluate characteristics of VEOIBD and later onset PIBD (LO-PIBD) in India.

METHODS

We performed retrospective analysis of a large, prospectively maintained IBD registry. PIBD was divided in to VEOIBD ( < 6 years) and LO-PIBD (6-17 years). Demographic data, disease characteristics and treatment were compared between the PIBD groups and with other Asian/Western studies as well as the adult patients of the registry.

RESULTS

Of 3,752 IBD patients, 292 (7.8%) had PIBD (0-17 years) (175 Crohn's disease [CD], 113 ulcerative colitis [UC], 4 IBD-undifferentiated; 22 VEOIBD [7.5%], and 270 LO-PIBD [92.5%]). VEOIBD patients had more severe disease compared to LO-PIBD in both UC (P= 0.003) and CD (P< 0.001). Familial IBD was more common in VEOIBD (13.6%) compared to LO-PIBD (9.2%). Ileal disease (L1) was an independent risk factor for diagnostic delay in pediatric CD. Diagnostic delay ( > 6 months) was significantly lower in VEOIBD (40.9%) than in LO-PIBD (78.8%) (P< 0.001). Compared to other Asian and Western studies, extensive UC (72.5%) and complicated CD (stricturing/penetrating: 42.7%) were relatively more common. Perianal CD was relatively less frequent (7.4%). PIBD had a significantly higher number of complicated and ileal CD and extensive UC comparison to adult cohort of the registry.

CONCLUSIONS

VEOIBD has more aggressive phenotype than LO-PIBD. Disease appears distinct from other Asian and Western studies and adult onset disease, with more complicated CD and extensive UC.

Epidemiology and diagnosis of inflammatory bowel diseases

Background: Over the past three decades, inflammatory bowel diseases (IBD) have been rapidly increasing in the African, South American, and Asian countries, including Korea. However, in Korea, the public awareness of IBD remains low, and diagnostic delay is not uncommon due to the physicians' lack of clinical experience. It is essential to understand the trends and regional differences in the epidemiology of IBD for proper diagnosis and treatment.Current Concepts: Although lower than those of the West, the prevalence and incidence of IBD in Korea rank among the highest in Asia and are steadily increasing. In the past 10 years, the prevalence of IBD has almost doubled, while its incidence has decreased gradually. As compared to Western IBD patients, Korean patients have higher proportion of proctitis in ulcerative colitis, male predominance, more ileocolonic involvement, and higher incidence of perianal fistula in Crohn disease. There is no single gold standard for the diagnosis of IBD. Thus, diagnosis can be made by clinical evaluation, including a detailed history taking, physical examination, and a combination of endoscopic, radiologic, laboratory, and histologic findings.Discussion and Conclusion: Population-based studies have revealed the current trends and characteristics of the epidemiology of IBD in Korea. Continued education and development of diagnostic tools will help clinicians to diagnose IBD accurately and differentiate it from other diseases such as intestinal tuberculosis.

Long-term Disease Course of Crohn's Disease: Changes in Disease Location, Phenotype, Activities, and Predictive Factors

Crohn's disease (CD) is a chronic destructive inflammatory bowel disease that affects young people and is associated with significant morbidity. The clinical spectrum and disease course of CD are heterogeneous and often difficult to predict based on the initial presentation. In this article, changes in the disease location, behavior, clinical course during long-term follow-up, and predictive factors are reviewed. Generally, four different patterns of clinical course are discussed: remission, stable disease, chronic relapsing disease, and chronic refractory disease. Understanding the long-term disease course of CD is mandatory to reveal the underlying pathophysiology of the disease and to move toward a more optimistic disease course, such as remission or stability, and less adverse outcomes or devastating sequelae.