Prevalence and Progression of Incidental Terminal Ileitis on Non-diagnostic Colonoscopy: A Systematic Review and Meta-analysis

Idiopathic terminal ileitis: myth or true entity?

PURPOSE OF REVIEW

Isolated terminal ileitis is an increasing phenomenon identified during colonoscopy. Idiopathic terminal ileitis (IDTI) is a diagnosis of exclusion, representing a significant challenge from a diagnostic and management point of view. This review provides an overview of the most recent and relevant evidence on idiopathic IDTI, focusing on its evolution, the natural history and the management strategies proposed in the literature.

RECENT FINDINGS

IDTI is uncommon, with a reported prevalence between 0.5 and 7%. The main differential is with Crohn's disease and intestinal tuberculosis in endemic countries. A proportion of patients (0-50%) can progress and develop Crohn's disease; however, there are no reliable predictive factors to stratify IDTI patients.

SUMMARY

IDTI is a challenging entity, with a small proportion of patients progressing to Crohn's disease over time thus requiring follow-up. Noninvasive modalities such as capsule endoscopy are useful for follow-up, but further research is required to better understand this entity.

Revised Algorithmic Approach to Differentiate Between Nonspecific and Specific Etiologies of Chronic Terminal Ileitis

INTRODUCTION

Chronic isolated terminal ileitis (TI) may be seen in Crohn's disease (CD) and intestinal tuberculosis (ITB) in addition to other etiologies that may be managed symptomatically. We developed a revised algorithm to distinguish patients with a specific etiology from a nonspecific etiology.

METHODS

Patients with chronic isolated TI followed up from 2007 to 2022 were retrospectively reviewed. A specific (ITB or CD) diagnosis was made based on standardized criteria, and other relevant data were collected. Using this cohort, validation of a previously suggested algorithm was conducted. Furthermore, based on the results of a univariate analysis, a multivariate analysis with bootstrap validation was used to develop a revised algorithm.

RESULTS

We included 153 patients (mean age 36.9 ± 14.6 years, males-70%, median duration-1.5 years, range: 0-20 years) with chronic isolated TI of whom 109 (71.2%) received a specific diagnosis (CD-69, ITB-40). On multivariate regression and validation statistics with a combination of clinical, laboratory, radiological, and colonoscopic findings, an optimism corrected c-statistic of 0.975 and 0.958 was obtained with and without histopathological findings, respectively. Revised algorithm, based on these, showed sensitivity, specificity, positive and negative predictive values, and overall accuracy of 98.2% (95% CI: 93.5-99.8), 75.0% (95% CI: 59.7-86.8), 90.7% (95% CI: 85.4-94.2), 94.3% (95% CI: 80.5-98.5) and 91.5%(95% CI:85.9-95.4), respectively. This was more sensitive and specific than the previous algorithm (accuracy 83.9%, sensitivity 95.5%, and specificity 54.6%).

DISCUSSION

We developed a revised algorithm and a multimodality approach to stratify patients with chronic isolated TI into specific and nonspecific etiologies with an excellent diagnostic accuracy, which could potentially avoid missed diagnosis and unnecessary side effects of treatment.

Mild Crohn's Disease: Definition and Management

PURPOSE OF REVIEW

Crohn's Disease (CD) is a chronic inflammatory disease that can lead to progressive damage to the gastrointestinal tract and significant disability. Early, "top-down" biologic therapy is recommended in moderate-to-severe CD to induce remission and to prevent hospitalization and complications. However, an estimated 20-30% of patients with CD have a mild disease course and may not garner sufficient benefit from expensive, immunosuppressing agents to justify their risks. Herein, we review characteristics of patients with mild CD, the available options for disease treatment and monitoring, and future directions of research.

RECENT FINDINGS

For ambulatory outpatients with low-risk, mild, ileal or ileocolonic CD, induction of remission with budesonide is recommended. For colonic CD, sulfasalazine is a reasonable choice, although other aminosalicylates have no role in the treatment of CD. No large, randomized trial has supported the use of antibiotics or antimycobacterials in the treatment of CD. Partial Enteral Nutrition and Crohn's Disease Exclusion Diets may be appropriate for inducing remission in some adult patients, with trials ongoing. Select patients with mild-to-moderate CD may benefit from maintenance therapy with azathioprines or gut specific biologics, such as vedolizumab. The role of complementary and alternative medicine is not well defined. The identification, risk stratification, and monitoring of patients with mild CD can be a challenging clinical scenario. Some patients with low risk of disease progression may be appropriate for initial induction of remission with budesonide or sulfasalazine, followed by close clinical monitoring. Future research should focus on pre-clinical biomarkers to stratify disease, novel therapies with minimal systemic immune suppression, and validation of rigorous clinical monitoring algorithms.

Isolated Terminal Ileitis in Children

Isolated terminal ileitis in adults is a well described entity that rarely progresses to Crohn disease (CD), and pediatric literature on this topic is very limited. We describe the prevalence, clinical, endoscopic, histologic, and radiological features, along with long-term outcome of isolated terminal ileitis in our institution. We reviewed charts of 956 children who underwent colonoscopy from 2013 to 2017. Thirty-three children had isolated histologically-defined terminal ileitis. Seventeen children were diagnosed with CD and 16 children had idiopathic terminal ileitis. Children with CD had higher prevalence of abnormal C-reactive protein levels, severe inflammation, and radiological evidence of bowel wall thickening compared with children with idiopathic ileitis. Children with idiopathic ileitis did not develop CD over a follow-up period of 83 months. In contrast to adults, CD is common in children with isolated terminal ileitis and those with idiopathic ileitis do well over long-term.

Etiological spectrum of isolated ileo-cecal ulcers in patients with gastrointestinal symptoms

Background

Isolated ileo-cecal region (ICR) ulcers may represent underlying Crohn's disease (CD), intestinal tuberculosis (ITB), bacterial infections (including typhoid), amoebiasis, eosinophilic enteritis, drug-induced sequelae, or neoplasm. Overlapping morphological and microscopic characteristics of many of these diseases make it challenging to unequivocally confirm a diagnosis.

Aims

The aim of the study was to investigate the etiology and clinical outcomes of isolated ileo-cecal ulcers discovered during an ileocolonoscopy in patients with gastrointestinal symptoms.

Methods

Patients with isolated ileo-cecal ulcers and symptoms within the age range of 10 - 80 years were included in the study (N = 100). Patients not giving consent (assent in case of a minor), with a prior diagnosis of tuberculosis or inflammatory bowel disease, with incomplete colonoscopy and associated colonic lesions other than ICR were excluded from the study. Demographics, clinical information, and relevant biochemical and serological tests were recorded. During the colonoscopy, multiple biopsies were taken from the ileo-cecal ulcers for histopathological examination. Repeat ileocolonoscopy was performed as needed in consenting patients.

Results

The mean age and mean duration of symptoms were 36.0 ± 15.6 years and 18.8 ± 21.6 months, respectively. The majority of the patients presented with abdominal pain (59%), followed by diarrhea (47%), weight loss (20%), gastrointestinal bleeding (15%), and fever (11%). A history of taking nonsteroidal anti-inflammatory drugs was present in only 5% of the patients. Mean hemoglobin, C-reactive protein, and albumin levels were 11.6 ± 2.8 g/dL, 6.9 ± 9.5 mg/L, and 3.7 ± 0.8 g/dL, respectively. Based on clinical, colonoscopic, and histopathological findings, initial treatment was symptomatic/antibiotics in 55%, anti-tubercular treatment in 21%, 5-aminosalicylic acid/steroids for CD in 13%, oral budesonide in 10% of patients, and one patient was referred for management of malignancy. Final diagnoses after 8 - 24 weeks of follow-up were non-specific ileitis/colitis (45%), CD (20%), ITB (18%), infective (7%), eosinophilic ileitis/colitis (6%), non-steroidal anti-inflammatory drug-induced (2%), and amoebic and malignant in 1% of patients each.

Conclusions

The majority of patients with ileo-cecal ulcers have specific etiologies. Non-specific ulcers at the ICR can be managed symptomatically; however, close follow-up is necessary as sometimes the ulcers may harbor an underlying specific disease.

Relevance for Patients

Isolated ileo-cecal ulcers are common findings during colonoscopy in both symptomatic and asymptomatic patients. The majority of these ulcers harbor underlying significant diseases that can cause morbidity and mortality if left undiagnosed and untreated. Reaching a specific diagnosis in such cases is not straightforward, and patients are often subjected to repeat examinations.

Incidentally Diagnosed Asymptomatic Crohn's Disease: A Retrospective Cohort Study of Long-Term Clinical Outcomes

Background

Crohn's disease (CD) is occasionally diagnosed in asymptomatic patients who have undergone colonoscopy or imaging for other reasons. The clinical outcome and optimal management of these patients remain poorly defined.

Methods

This was a retrospective cohort study of asymptomatic patients with incidental diagnosis of CD from the electronic patient registry of the IBD Unit of Sheba Medical Center in Israel. The primary outcome was defined as the occurrence of a clinical flare.

Results

Of the 2700 CD patients in Sheba IBD registry, 60 asymptomatic patients with incidental diagnosis of CD were identified (31/60 males, median age 50.5, 25%-75% interquartile range [IQR] 43.5-57.25 years, median follow-up 4.5 years, 25-75% IQR 2.5-6.75, range 1-15 years). Most of the patients did not receive any treatment after diagnosis (53/60-88.33%). Of these, 5 patients (9.43%) experienced a flare during follow-up (median 4.5 years, IQR 2.5-6.75, range 1-15 years). Patients with subsequent flare had numerically higher CRP at diagnosis than patients who did not flare (2.2, IQR 2.0-3.0 vs 1.04, IQR 1.0-2.2, P = .09). When comparing the group of patients who received treatment immediately after diagnosis (n = 7) with the group who did not receive treatment (n = 53), there was no difference with respect to the survival time without a flare (P = .3). For other secondary outcomes, 3/40 progressed from B1 phenotype to B2, and 3/53 (6%) patients underwent surgery during the follow-up.

Conclusions

The majority of patients with an incidental diagnosis of asymptomatic CD can probably be followed-up without immediate treatment. Although most remain asymptomatic and without complications during follow-up, close monitoring for disease progression is prudent.

Nonspecific ileitis: Impact of histopathology and gastrointestinal ultrasound in achieving the diagnosis of Crohn's disease

Background and Aim

Nonspecific ileitis is inflammation of the ileum without specific diagnostic features. A minority may go on to develop Crohn's disease, but optimal pathways of further investigation have not been established. This study aimed to identify a cohort of patients with nonspecific ileitis and to determine the value of ileal histology and gastrointestinal ultrasound in identifying/excluding Crohn's disease.

Patients and Methods

In a retrospective analysis, all patients having nonspecific ileitis at colonoscopy from January 2010 to August 2021 were identified. Clinical associations with those subsequently diagnosed with Crohn's disease were examined with specific reference to ileal histology and gastrointestinal ultrasound.

Results

Of 29 638 procedures, 147 patients (0.5%) had nonspecific ileitis. Crohn's disease was subsequently diagnosed in 8 patients (5.4%) at a median of 148 (range 27–603) days after colonoscopy. The presence of chronic inflammation on ileal biopsies was more common in those subsequently diagnosed with Crohn's disease (63% vs 20%; P = 0.0145). On gastrointestinal ultrasound, none of the 26 patients with normal bowel wall thickness (<3 mm) were subsequently diagnosed with Crohn's disease, and repeat ultrasound in 15 patients 1 year later showed no change. Of the nine patients with abnormal sonographic findings, three were diagnostic for Crohn's disease. Repeat ultrasound revealed Crohn's disease in two, while four had resolution of the abnormal findings.

Conclusion

Although ileal histology was of limited value in identifying patients with nonspecific ileitis who were subsequently diagnosed with Crohn's disease, gastrointestinal ultrasound was highly informative. Prospective studies are needed to confirm the value of gastrointestinal ultrasound as a diagnostic and monitoring tool in this setting.

Approach to the Management of Recently Diagnosed Inflammatory Bowel Disease Patients: A User's Guide for Adult and Pediatric Gastroenterologists

Inflammatory bowel diseases (IBDs), including Crohn's disease and ulcerative colitis, are chronic, progressive, immune-mediated diseases of adults and children that have no cure. IBD can cause significant morbidity and lead to complications such as strictures, fistulas, infections, and cancer. In children, IBD can also result in growth impairment and pubertal delays. IBD is highly heterogenous, with severity ranging from mild to severe and symptoms ranging from mild to debilitating. Delay in IBD diagnosis, especially in Crohn's disease, is common and associated with adverse outcomes. Early diagnosis and prompt institution of treatment are the cornerstones for improving outcomes and maximizing health. Early diagnosis requires a low threshold of suspicion and red flags to guide early specialist referral at the primary provider level. Although the armamentarium of IBD medications is growing, many patients will not respond to treatment, and the selection of first-line therapy is critical. Risk stratification of disease severity, based on clinical, demographic, and serologic markers, can help guide selection of first-line therapy. Clinical decision support tools, genomics, and other biomarkers of response to therapy and risk of adverse events are the future of personalized medicine. After starting appropriate therapy, it is important to confirm remission using objective end points (treat to target) with continued control of inflammation with adjustment of therapy using surrogate biomarkers (tight control). Lastly, IBD therapy extends far beyond medications, and other aspects of the overall health and wellbeing of the patient are critical. These include preventive health, nutrition, and psychobehavioral support addressing patients' concerns around complementary therapy and medication adherence, prevention of disability, and ensuring open communication.