Diagnosis and differential diagnosis of Crohn's disease of the ileal pouch

Ouch, my pouch! a clinician's guide to pouchitis

Pouchitis is defined as inflammation of the ileal pouch created during a restorative proctocolectomy with ileal pouch-anal anastomosis. Although the incidence of this inflammatory condition is high, the exact etiology often remains unclear and the management challenging. In this review, we summarize the clinical presentation, pathogenesis, diagnosis, and management of this common complication.

Risks Factors Associated with the Development of Crohn's Disease After Ileal Pouch-Anal Anastomosis for Ulcerative Colitis: A Systematic Review and Meta-Analysis

BACKGROUND

Following ileal pouch-anal anastomosis [IPAA] for ulcerative colitis [UC], up to 16% of patients develop Crohn's disease of the pouch [CDP], which is a major cause of pouch failure. This systematic review and meta-analysis aimed to identify preoperative characteristics and risk factors for CDP development following IPAA.

METHODS

A literature search of the MEDLINE, EMBASE, EMCare and CINAHL databases was performed for studies that reported data on predictive characteristics and outcomes of CDP development in patients who underwent IPAA for UC between January 1990 and August 2022. Meta-analysis was performed using random-effect models and between-study heterogeneity was assessed.

RESULTS

Seven studies with 1274 patients were included: 767 patients with a normal pouch and 507 patients with CDP. Age at UC diagnosis (weighted mean difference [WMD] -2.85; 95% confidence interval [CI] -4.39 to -1.31; p = 0.0003; I2 54%) and age at pouch surgery [WMD -3.17; 95% CI -5.27 to -1.07; p = 0.003; I2 20%) were significantly lower in patients who developed CDP compared to a normal pouch. Family history of IBD was significantly associated with CDP (odds ratio [OR] 2.43; 95% CI 1.41-4.19; p = 0.001; I2 31%], along with a history of smoking [OR 1.80; 95% CI 1.35-2.39; p < 0.0001; I2 0%]. Other factors such as sex and primary sclerosing cholangitis were found not to increase the risk of CDP.

CONCLUSIONS

Age at UC diagnosis and pouch surgery, family history of IBD and previous smoking have been identified as potential risk factors for CDP post-IPAA. This has important implications towards preoperative counselling, planning surgical management and evaluating prognosis.

Crohn's Disease of the Ileoanal Pouch: A High Rate of Potential Overdiagnoses

BACKGROUND

Approximately 1 in 10 patients with an ileal pouch-anal anastomosis is diagnosed with Crohn's disease of the pouch (CDP). However, this diagnosis may be established inappropriately, as alternative underlying causes necessitating an alternative treatment approach, such as long-term surgical sequelae, may mimic CDP. In this study, we aimed to identify patients diagnosed with and treated for CDP with a (concurrent) alternative diagnosis.

METHODS

Ulcerative colitis and inflammatory bowel disease unclassified patients who underwent ileal pouch-anal anastomosis surgery in a tertiary center between 1990 and 2017 were retrospectively reviewed. Patients with a postoperative diagnosis of CDP for which medical treatment was initiated were identified. Presence of pouchitis, prepouch ileitis, stricture, and fistulas was assessed and histopathological reports were evaluated. Thereafter, cross-sectional images of the pouch in CDP patients were re-evaluated to identify potential long-term surgical sequelae (ie, chronic presacral sinus or perianastomotic fistulas).

RESULTS

After a median postoperative follow-up of 6.2 (interquartile range, 2.3-13.5) years, 47 (10%) of 481 patients were diagnosed with CDP. CDP patients had pouchitis (n = 38 [81%]), prepouch ileitis (n = 34 [74%]), strictures (n = 17 [36%]), fistulas (n = 15 [32%]), or a combination. Multiple granulomas were found in 1 pouch resection specimen. Re-evaluation of 40 (85%) patients who underwent magnetic resonance imaging revealed presence of long-term surgical sequelae in 17 (43%) patients. Six (15%) patients demonstrated isolated nonanastomotic fistulas.

CONCLUSION

Re-evaluation of cross-sectional imaging of the pouch revealed that potential alternative causes were found in nearly half of CDP patients. Cross-sectional imaging is therefore recommended early in the diagnostic pathway to exclude an alternative diagnosis.

Diagnostic and Management Considerations for the IPAA With Crohn's Disease-Like Features

BACKGROUND

Patients with ulcerative colitis often develop medically refractory colonic inflammation or colorectal neoplasia, and approximately 10% to 15% of patients require surgery. The most common surgical procedure is a restorative proctocolectomy with IPAA. Even if the preoperative diagnosis is ulcerative colitis, approximately 10% of patients can develop inflammatory pouch conditions resembling a Crohn's disease phenotype.

OBJECTIVE

This study aimed to review the diagnostic approach, prognosis, and management of IPAA with Crohn's disease-like features.

DATA SOURCES

The data sources include search in electronic databases.

STUDY SELECTION

This narrative review included studies focusing on pouches with Crohn's disease-like features.

MAIN OUTCOME MEASURES

The main topics in this review included the pathogenesis, risk factors, diagnosis, phenotypes, prognosis, and medications of pouches with Crohn's disease-like features.

RESULTS

A diagnostic approach for the pouch conditions resembling a Crohn's disease phenotype should be based on history-taking to evaluate its risk factors and endoscopic assessment of the pouch. Prior disease history and pathology, location of pouch complications, and timing of complications offer clues for the differential diagnosis of this phenotype. We advocate for the more descriptive term "pouch with Crohn's disease-like features" and reserve the term "Crohn's disease of the pouch" for patients who undergo IPAA and have a precolectomy diagnosis of Crohn's disease or whose colectomy pathology revealed Crohn's disease. Medications, which are often used for traditional Crohn's disease, show efficacy in pouches with Crohn's disease-like features as well. The poor prognosis associated with pouches with Crohn's disease-like features, particularly the fistulizing phenotype, underscores the importance of proactive monitoring and therapeutic intervention.

LIMITATIONS

The limitations include no explicit criteria for article selection.

CONCLUSIONS

This review suggests future research should seek to understand the natural history and meaningful shorter and longer term therapeutic targets for these types of pouch phenotypes. Long-term follow-up and prospective preoperative and postoperative interventional trials of treatments and prevention strategies are needed.

Histopathology of Colectomy Specimens Predicts Endoscopic Pouch Phenotype in Patients with Ulcerative Colitis

BACKGROUND

The endoscopic appearance in patients with "pouchitis" after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) can be quite heterogenous. Patients with an endoscopic phenotype resembling Crohn's disease (CD) are at high risk of pouch loss.

AIMS

We aimed to assess how the histopathology of colectomy specimens predicts endoscopic pouch phenotypes in UC.

METHODS

We retrospectively assessed pouchoscopies from patients with UC who underwent IPAA and classified pouch findings into 7 main phenotypes: (1) normal, (2) afferent limb involvement, (3) inlet involvement, (4) diffuse, (5) focal inflammation of the pouch body, (6) cuffitis, and (7) pouch with fistulas noted ≥ 6 months from ileostomy takedown. We assessed the clinical and pathological data including deep, focal inflammation, granulomas, and terminal ileal involvement in the colectomy specimens. Logistic regression analysis was performed to identify contributing factors to each phenotype.

RESULTS

This study included 1,203 pouchoscopies from 382 patients with UC. On multivariable analysis, deep inflammation was significantly associated with pouch fistulas (Odds ratio 3.27; 95% confidence interval 1.65-6.47; P = 0.0007). Of the 75 patients with deep inflammation, only two patients (2.7%) were diagnosed with CD based on pathology review. Terminal ileal involvement significantly increased the risk of afferent limb involvement (Odds ratio 2.96; 95% confidence interval 1.04-8.47; P = 0.04). There were no significant associations between other microscopic features and phenotypes.

CONCLUSIONS

We identify histologic features of colectomy specimens in UC that predict subsequent pouch phenotypes. Particularly, deep inflammation in the resected colon was significantly associated with pouch fistulas, a pouch phenotype with poor prognosis.

A systematic review and meta-analysis of the outcome of ileal pouch-anal anastomosis in patients with ulcerative colitis versus patients with familial adenomatous polyposis

BACKGROUND

Ileal pouch-anal anastomosis (IPAA) is commonly used to restore gastrointestinal continuity after surgical treatment of mucosal ulcerative colitis (MUC) and familial adenomatous polyposis (FAP). The aim of the present systematic review was to compare the outcomes of patients with MUC and patients with FAP who underwent IPAA.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-compliant systematic review was performed. PubMed, Scopus, and Web of Science were searched through December 2021. Cohort and randomized studies were eligible for inclusion if they directly compared patients with MUC and FAP who underwent IPAA. The main outcome measures were pouch failure, complications, and need for pouch excision or revision. ROBINS-I tool was used to assess the risk of bias across the studies. A random-effect meta-analysis was conducted.

RESULTS

Twenty-three studies (9200 patients) were included in this meta-analysis. Seven thousand nine hundred fifty (86.4%) had MUC and 1250 (13.6%) had FAP. The median age of patients was 33.1 years. The male to female ratio was 1.4:1. MUC had higher odds of pouchitis (OR 3.9, 95% CI 2.8-5.4, p < 0.001), stricture (OR 1.82, 95% CI 1.25-2.65, p = 0.002), fistula (OR 1.74, 95% CI 1.18-2.54, p = 0.004), and total complications (OR 1.89, 95% CI 1.3-2.77, p < 0.001) as compared to FAP. Both groups had similar odds of pelvic sepsis, leakage, pouch failure, excision, revision, and fecal incontinence.

CONCLUSIONS

Although patients with MUC undergoing IPAA may be at a higher risk of developing complications, particularly pouchitis, stricture, and fistula; the ultimate and functional outcome of the pouch is similar to patients with FAP. Pouch failure, excision and revision were similar in the two groups.

Prevalence of pouchitis in both ulcerative colitis and familial adenomatous polyposis: A systematic review and meta-analysis

AIM

Pouchitis is a clinically significant complication of ileal pouch-anal anastomosis with its prevalence varying in the literature. Pouchitis is thought to occur more commonly in patients with ulcerative colitis (UC) than in patients with familial adenomatous polyposis (FAP). We conducted a systematic review with meta-analysis of all published literature to report the prevalence of pouchitis in all pouch patients as well as specifically in UC and FAP. We also investigated the prevalence of acute and chronic pouchitis in UC and FAP.

METHODS

A meta-analysis was conducted by searching the Embase, Embase Classic and PubMed databases between 1978 and 2021 exploring the prevalence of pouchitis in UC and FAP. We then performed a random effects model in order to find the pooled prevalence of pouchitis and used odds ratios to report differences in the prevalence of pouchitis in UC and FAP.

RESULTS

Fifty-nine full papers and conference abstracts were included in the meta-analysis comprising 18 117 patients with UC and 860 with FAP. The prevalence of pouchitis in UC was 0.32 (95% CI 0.27-0.37) and in FAP was found to be 0.06 (95% CI 0.03-0.15). The odds ratio of pouchitis in UC patients compared with FAP patients was 4.95 (95% CI 3.17-7.72, P < 0.0001).

CONCLUSIONS

Our findings support the consensus that the prevalence of pouchitis is higher in UC than in FAP. More significantly our findings suggest that the true prevalence of pouchitis is higher than commonly reported in the literature. This literature may help counsel patients prior to undergoing restorative proctocolectomy.

Antitumour necrosis factor therapy is associated with de novo Crohn's disease after ileal pouch-anal anastomosis

AIM

Tumour necrosis factor inhibitors (TNFi) have revolutionized the management of moderate to severe ulcerative colitis (UC) since their approval for UC in 2005. However, many patients ultimately require surgery with ileal pouch-anal anastomosis (IPAA). Development of de novo Crohn's disease (CD) following IPAA is an increasingly common and devastating complication, sometimes progressing to pouch failure. The aim of this study was to evaluate the association of preoperative TNFi exposure and the development of de novo CD after IPAA.

METHOD

A prospective single-centre inflammatory bowel disease (IBD) registry was searched for consecutive patients with UC undergoing IPAA during a 25-year period ending July 2018. Patients with preoperative CD or IBD-unclassified were excluded. De novo CD was diagnosed upon endoscopic evidence of five or more mucosal ulcers proximal to the ileal pouch any time after surgery and/or pouch fistula occurring more than three months after ileostomy closure.

RESULTS

The study cohort consisted of 400 patients with a median follow-up of 44.0 (IQR 11-113) months. Sixty-two (16%) patients developed de novo CD 28.0 (IQR 6-67) months following ileostomy closure. Survival analysis of TNFi era patients revealed a significant increase in de novo CD risk in those with preoperative TNFi exposure. Multivariable proportional hazards modelling revealed two independent predictors for de novo CD development: older age was protective (HR 0.89 per 5-year increase; P = 0.009) and preoperative TNFi exposure was hazardous (HR 2.10; P = 0.011).

CONCLUSION

This prospective study is the first to suggest an association between preoperative TNFi exposure and the development of de novo CD.

The pouch behaving badly: management of morbidity after ileal pouch-anal anastomosis

AIM

Ileal pouch-anal anastomosis (IPAA), or a 'pouch', allows restoration of intestinal continuity after proctocolectomy for ulcerative colitis or familial adenomatous polyposis. Most patients have a good long-term outcome after IPAA, but in a significant proportion the functional outcome and quality of life are unsatisfactory. We term this outcome 'the pouch behaving badly'. Managing this, especially one is when unfamiliar with the possible underlying pathologies, is a challenge for both patient and clinician. We aim to outline the clinical approach to the pouch behaving badly, highlighting key aspects of investigation and management.

METHOD

This is a narrative review of the literature covering the investigation and management of postoperative complications and morbidity after IPAA.

RESULTS

Management of the pouch behaving badly requires a careful clinical assessment. The patient may present with multiple symptoms and a clear picture of the symptomatology and past history should be constructed before thorough examination and specialist investigation. We divide the pathology that underlies this clinical scenario into surgical, inflammatory, mechanical, functional and dysplastic causes and outline the investigation and management of each one.

CONCLUSION

The pouch behaving badly is a challenging problem for both patient and clinician. A detailed clinical assessment with careful specialist investigation is key to diagnosing the underlying pathology. We stress the importance of patient-centred care - the aim is to improve quality of life.

Pyloric gland metaplasia: Potential histologic predictor of severe pouch disease including Crohn's disease of the pouch in ulcerative colitis

Crohn's disease of the pouch (CDP) is seen in a subset of ulcerative colitis (UC) patients following ileal pouch-anal anastomosis (IPAA). Histologic or clinical predictors of CDP are unknown. UC patients with subsequent CDP diagnosis were identified. The rationales for the diagnosis, the interval from the initial signs of CDP to the diagnosis, family history and smoking history were reviewed. Archived pathology materials were reviewed for the presence of pyloric gland metaplasia (PGM) and compared with those from UC with similar severity of pouchitis with CDP (matched UC controls), random UC controls, and ileocolectomies from primary CD patients. CDP diagnosis was made in 26 (18.1%) of 144 patients; all of them met commonly used diagnostic criteria for CDP. The diagnosis was rendered on average 15 months after the initial CD-like signs. PGM was found in 58% of CDP, more common than random UC controls but no different from primary CD and matched UC controls. PGM preceded first signs of CD in a subset. Patients with a family history of CD were more likely to develop CDP than those without a family history of any type of inflammatory bowel disease. Smoking status did not affect the likelihood of developing CDP. Finding PGM in proctocolectomy, ileostomy and follow-up biopsies in UC patients post IPAA may warrant close follow up for the potential development of pouchitis. Some of these patients, especially those with family history of CD, may further progress and develop severe disease meeting the clinical diagnostic criteria for CDP.

Modern surgical strategies for perianal Crohn's disease

One of the most challenging phenotypes of Crohn’s disease is perianal fistulizing disease (PFCD). It occurs in up to 50% of the patients who also have symptoms in other parts of the gastrointestinal tract, and in 5% of the cases it occurs as the first manifestation. It is associated with severe symptoms, such as pain, fecal incontinence, and a significant reduction in quality of life. The presence of perianal disease in conjunction with Crohn’s disease portends a significantly worse disease course. These patients require close monitoring to identify those at risk of worsening disease, suboptimal biological drug levels, and signs of developing neoplasm. The last 2 decades have seen significant advancements in the management of PFCD. More recently, newer biologics, cell-based therapies, and novel surgical techniques have been introduced in the hope of improved outcomes. However, in refractory cases, many patients face the decision of having a stoma made and/or a proctectomy performed. In this review, we describe modern surgical management and the most recent advances in the management of complex PFCD, which will likely impact clinical practice.

Perioperative and Postoperative Management of Patients With Crohn's Disease and Ulcerative Colitis

Although the number of available therapies for the treatment of ulcerative colitis and Crohn's disease (CD) continues to expand, a significant portion of patients with inflammatory bowel disease will require surgical intervention. Surgery remains an integral part of the treatment algorithm for patients with ulcerative colitis and CD, and thus multidisciplinary approaches to the perioperative and postoperative management of patients with inflammatory bowel disease are critical to improving outcomes during these periods. New mechanisms of biologic therapies are emerging and new treatment strategies focused on earlier and potentially more aggressive use of immunosuppressive therapies are advocated in the current treatment era. In this review, we outline multidisciplinary strategies for the preoperative management of immunosuppressive therapies, including a discussion of the most recent evidence regarding the safety of biologic therapy in the preoperative period. We also discuss the postoperative medical management of patients undergoing intestinal resection for CD, with a particular focus on risk stratification and appropriate therapy selection in the immediate postoperative setting. Finally, we review potential postoperative complications after restorative proctocolectomy with ileal pouch-anal anastomosis and their management.

DIAGNOSTIC AND MANAGEMENT APPROACH TO POUCHITIS IN INFLAMMATORY BOWEL DISEASE

In patients with ulcerative colitis refractory to medical therapy, total proctocolectomy and posterior ileal-anal pouch anastomosis is the standard surgical therapy. One of the possible complications is pouchitis. Depending on the duration of the symptoms, it can be classified as acute, recurrent, or chronic. The latter, according to the response to therapy, can be defined as antibiotic-dependent or refractory. The treatment of pouchitis is based on the use of antibiotics and probiotics. Thiopurine and biological therapy have been suggested in patients with refractory pouchitis. Special care should be taken in the endoscopic surveillance of these patients, especially if they present risk factors such as dysplasia or previous colorectal cancer, primary sclerosing cholangitis or ulcerative colitis for more than 10 years.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

The Incidence and Definition of Crohn's Disease of the Pouch: A Systematic Review and Meta-analysis

BACKGROUND

A subset of patients who undergo total proctocolectomy with ileal pouch-anal anastomosis (IPAA) creation for ulcerative colitis (UC) will later develop Crohn's disease (CD) of the pouch, which has been associated with significant morbidity. We aimed to analyze the incidence of CD of the pouch and to review the existing diagnostic criteria utilized.

METHODS

A systematic search performed through March 1, 2018, identified 12 studies that reported the incidence of CD of the pouch after IPAA for UC or indeterminate colitis (IC). We compiled all diagnostic criteria utilized in these studies and then performed a meta-analysis using random effects modeling to estimate the overall incidence of CD of the pouch in this population.

RESULTS

Among 4843 patients with an IPAA for UC or IC, 10.3% of patients were ultimately diagnosed with CD of the pouch (95% confidence interval [CI], 6.1%-15.4%). The most commonly reported diagnostic criteria were (1) presence of fistula/fistulae, (2) stricture involving the pouch or prepouch ileum, and (3) presence of prepouch ileitis. In a secondary analysis, excluding those studies that included patients with a preoperative diagnosis of IC, the incidence of CD of the pouch was 12.4% (95% CI, 9.0%-16.1%).

CONCLUSIONS

The estimated incidence of 10.3% will assist gastroenterologists and surgeons in preoperative counseling regarding the potential to develop CD of the pouch. There is an unmet need for common diagnostic criteria for a more standardized approach to the diagnosis of CD of the pouch.

Reliability among central readers in the evaluation of endoscopic disease activity in pouchitis

BACKGROUND AND AIMS

Pouchitis is a common adverse event after proctocolectomy with ileal pouch anal anastomosis for ulcerative colitis. Evaluation of pouchitis disease activity and response to treatment requires use of validated indices. We assessed the reliability of items evaluating endoscopic pouchitis disease activity.

METHODS

Twelve panelists used a modified RAND appropriateness methodology to rate the appropriateness of items evaluating endoscopic pouchitis disease activity derived from a systematic review and also identified additional potential endoscopic items based on expert opinion. Four central readers then evaluated 50 pouchoscopy videos in triplicate, in random order. Intra- and inter-rater reliability for each item was assessed by calculating and comparing intraclass correlation coefficients (ICCs). A Delphi process identified common sources of disagreement among the readers.

RESULTS

Ten existing endoscopic items were identified from the systematic review and an additional 7 exploratory items from the panelists. ICCs for inter-rater reliability were highest for the existing item of pouch ulceration (.72; 95% confidence interval [CI], .60-.82) and for the exploratory item of ulcerated surface in the pouch body (.67; 95% CI, .53-.75). Inter-rater reliability for all other existing and exploratory items was "moderate" (ICC < .60). The item "ulcerated surface in the pouch body" demonstrated the best correlation with a global evaluation of lesion severity (r = .80; 95% CI, .73-.85).

CONCLUSION

Substantial reliability was observed only for the endoscopic items of ulceration and ulcerated surface in the pouch body. Future studies should assess responsiveness to treatment in the next stage toward development of an endoscopic pouchitis disease activity index.

Pouchitis after ileal pouch-anal anastomosis in ulcerative colitis: Diagnosis, management, risk factors, and incidence

Restorative proctocolectomy with ileal pouch-anal anastomosis has been the surgical treatment of choice for patients with ulcerative colitis who require surgery. Quality of life after this procedure is satisfactory in most cases; however, pouchitis is a troublesome condition involving inflammation of the ileal pouch. When a patient presents with symptoms of pouchitis, such as increased bowel movements, mucous and/or bloody exudates, abdominal cramps, and fever, endoscopy is essential for a precise diagnosis. The proximal ileum and rectal cuff, as well as the ileal pouch, should be endoscopically observed. The reported incidence of pouchitis ranges from 14% to 59%, and antibiotic therapy is the primary treatment for acute pouchitis. Chronic pouchitis includes antibiotic-dependent and refractory pouchitis. Intensive therapy including antitumor necrosis factor antibodies and steroids may be necessary for antibiotic-refractory pouchitis, and pouch failure may occur despite such intensive treatment. Reported risk factors for the development of pouchitis include presence of extraintestinal manifestations, primary sclerosing cholangitis, non-smoking, and postoperative non-steroidal anti-inflammatory drug usage. In the present review, we focus on the diagnosis, endoscopic features, management, incidence, and risk factors of pouchitis in patients with ulcerative colitis who underwent ileal pouch-anal anastomosis.

Human alpha defensin 5 is a candidate biomarker to delineate inflammatory bowel disease

Inability to distinguish Crohn's colitis from ulcerative colitis leads to the diagnosis of indeterminate colitis. This greatly effects medical and surgical care of the patient because treatments for the two diseases vary. Approximately 30 percent of inflammatory bowel disease patients cannot be accurately diagnosed, increasing their risk of inappropriate treatment. We sought to determine whether transcriptomic patterns could be used to develop diagnostic biomarker(s) to delineate inflammatory bowel disease more accurately. Four patients groups were assessed via whole-transcriptome microarray, qPCR, Western blot, and immunohistochemistry for differential expression of Human α-Defensin-5. In addition, immunohistochemistry for Paneth cells and Lysozyme, a Paneth cell marker, was also performed. Aberrant expression of Human α-Defensin-5 levels using transcript, Western blot, and immunohistochemistry staining levels was significantly upregulated in Crohn's colitis, p< 0.0001. Among patients with indeterminate colitis, Human α-Defensin-5 is a reliable differentiator with a positive predictive value of 96 percent. We also observed abundant ectopic crypt Paneth cells in all colectomy tissue samples of Crohn's colitis patients. In a retrospective study, we show that Human α-Defensin-5 could be used in indeterminate colitis patients to determine if they have either ulcerative colitis (low levels of Human α-Defensin-5) or Crohn's colitis (high levels of Human α-Defensin-5). Twenty of 67 patients (30 percent) who underwent restorative proctocolectomy for definitive ulcerative colitis were clinically changed to de novo Crohn's disease. These patients were profiled by Human α-Defensin-5 immunohistochemistry. All patients tested strongly positive. In addition, we observed by both hematoxylin and eosin and Lysozyme staining, a large number of ectopic Paneth cells in the colonic crypt of Crohn's colitis patient samples. Our experiments are the first to show that Human α-Defensin-5 is a potential candidate biomarker to molecularly differentiate Crohn's colitis from ulcerative colitis, to our knowledge. These data give us both a potential diagnostic marker in Human α-Defensin-5 and insight to develop future mechanistic studies to better understand crypt biology in Crohn's colitis.

Common Inflammatory Disorders and Neoplasia of the Ileal Pouch: A Review of Histopathology

Ileal pouch-anal anastomosis (IPAA) is the standard restorative procedure after proctocolectomy in patients with ulcerative colitis (UC) who require colectomy. The ileal pouch is susceptible to a variety of insults including mechanical injury, ischemia, fecal stasis, and infectious agents. In addition, the development of recurrent and idiopathic inflammatory bowel disease and neoplasia may occur in the ileal pouch. Although clinical, endoscopic, and radiographic examination can diagnose many ileal pouch diseases, histologic examination plays an essential role in diagnosis and management, particularly in cases with antibiotic refractory chronic pouchitis and pouch neoplasia.

Crohn's Disease of the Ileoanal Pouch

Crohn's disease (CD) of the pouch is an increasingly recognized diagnosis after ileal pouch-anal anastomosis. This post-ileal pouch-anal anastomosis diagnosis in conjunction with pouchitis remains the leading reason for pouch excision. Unfortunately, CD of the pouch remains a difficult diagnosis with lack of a uniform definition largely because of its similarity to common postoperative pouch complications, including pouchitis, abscess formation, or stricture at the anastomosis. Once diagnosed, treatment algorithms largely include multimodal therapy including biologics. This review focuses on the definition, etiology, diagnosis, and treatment for CD of the pouch, a postoperative de novo diagnosis of CD.

Inflammatory pouch disease: The spectrum of pouchitis

Restorative proctocolectomy with ileal-pouch anal anastomosis (IPAA) is the operation of choice for medically refractory ulcerative colitis (UC), for UC with dysplasia, and for familial adenomatous polyposis (FAP). IPAA can be a treatment option for selected patients with Crohn’s colitis without perianal and/or small bowel disease. The term “pouchitis” refers to nonspecific inflammation of the pouch and is a common complication in patients with IPAA; it occurs more often in UC patients than in FAP patients. This suggests that the pathogenetic background of UC may contribute significantly to the development of pouchitis. The symptoms of pouchitis are many, and can include increased bowel frequency, urgency, tenesmus, incontinence, nocturnal seepage, rectal bleeding, abdominal cramps, and pelvic discomfort. The diagnosis of pouchitis is based on the presence of symptoms together with endoscopic and histological evidence of inflammation of the pouch. However, “pouchitis” is a general term representing a wide spectrum of diseases and conditions, which can emerge in the pouch. Based on the etiology we can sub-divide pouchitis into 2 groups: idiopathic and secondary. In idiopathic pouchitis the etiology and pathogenesis are still unclear, while in secondary pouchitis there is an association with a specific causative or pathogenetic factor. Secondary pouchitis can occur in up to 30% of cases and can be classified as infectious, ischemic, non-steroidal anti-inflammatory drugs-induced, collagenous, autoimmune-associated, or Crohn’s disease. Sometimes, cuffitis or irritable pouch syndrome can be misdiagnosed as pouchitis. Furthermore, idiopathic pouchitis itself can be sub-classified into types based on the clinical pattern, presentation, and responsiveness to antibiotic treatment. Treatment differs among the various forms of pouchitis. Therefore, it is important to establish the correct diagnosis in order to select the appropriate treatment and further management. In this editorial, we present the spectrum of pouchitis and the specific features related to the diagnosis and treatment of the various forms.

An Esophagogastroduodenal Crohn's-Like Disease in a Long-Standing Pan-Ulcerative Colitis Patient

Inflammatory bowel disease (IBD) comprises the principal subtypes Crohn's disease (CD) and ulcerative colitis (UC), with a fraction remaining as IBD unclassified (IBDU). Given the complexity of IBD manifestations in a patient over time and our increasing understanding of IBD biology, a modification in subtype diagnosis can also occur. Herein is a case of a 27-year-old female with well-controlled and long-standing pan-UC, who developed Crohn's-like esophagogastroduodenitis. The difficulty in classifying IBD into a single traditional subtype, and the debated presentation of a coexistent IBD will be discussed.

Endoscopic therapy in inflammatory bowel diseases (with videos)

Endoscopic therapies are important modalities in the treatment of IBD, adjunct to medical and surgical approaches. These therapeutic techniques are particularly useful in the management of IBD-associated or IBD surgery–associated strictures, fistulas, and sinuses and colitis-associated neoplasia. Although the main focus of endoscopic therapies in IBD has been on balloon stricture dilation and ablation of adenoma-like lesions, new endoscopic approaches are emerging, including needle-knife stricturotomy, needle-knife sinusotomy, endoscopic stent placement, and fistula tract injection. Risk management of endoscopy-associated adverse events is also evolving. The application of endoscopic techniques in novel ways in the treatment of IBD is just beginning and will likely expand rapidly in the near future.