Guidelines for the investigation of chronic diarrhoea in adults: British Society of Gastroenterology, 3rd edition

Identification of COL3A1 as a candidate protein involved in the crosstalk between obesity and diarrhea using quantitative proteomics and machine learning

BACKGROUND

Increasing epidemiologic studies have shown a positive correlation between obesity and chronic diarrhea. Nevertheless, the precise etiology remains uncertain.

METHODS

We performed a comprehensive proteomics analysis utilizing the data-independent acquisition (DIA) technique on jejunal tissues from patients with obesity and chronic diarrhea (OD, n = 33), obese patients (OB, n = 10), and healthy controls (n = 8). Differentially expressed proteins (DEPs) in OD vs. control and OD vs. OB comparisons were subjected to pathway enrichment and protein-protein interaction (PPI) network analysis. Machine learning algorithms were adopted on overlapping DEPs in both comparisons. The candidate protein was further validated using Western blot, immunohistochemistry (IHC), and in vitro experiments.

RESULTS

We identified 189 and 228 DEPs in OD vs. control and OD vs. OB comparisons, respectively. DEPs in both comparisons were co-enriched in extracellular matrix (ECM) organization. Downregulated DEPs were associated with tight junction and ECM-receptor interaction in OD vs. control and OD vs. OB comparisons, respectively. Machine learning algorithms selected 3 proteins from 14 overlapping DEPs in both comparisons, among which collagen alpha-1(III) chain (COL3A1) was identified as a core protein in PPI networks. Western blot and IHC verified the expression of COL3A1. Moreover, the tight junction-related proteins decreased after the knockdown of COL3A1 in Caco2 intestinal cells upon PA challenge, consistent with the proteomics results.

CONCLUSIONS

We generated in-depth profiling of a proteomic dataset from samples of OD patients and provided unique insights into disease pathogenesis. COL3A1 was involved in the crosstalk between obesity and intestinal homeostasis via the ECM-receptor interaction pathway.

Development and validation of a novel 7α-hydroxy-4-cholesten-3-one (C4) liquid chromatography tandem mass spectrometry method and its utility to assess pre-analytical stability

OBJECTIVES

7α-Hydroxy-4-cholesten-3-one (C4) is the common intermediary of both primary bile acids. C4 is recommended by the British Society of Gastroenterology for the investigation of bile acid diarrhoea (BAD) in patients with chronic diarrhoea. This project aimed to develop and validate an assay to quantitate C4 in serum and assess the stability of C4 in unseparated blood.

METHODS

Accuracy was underpinned by calibrating to quantitative nuclear magnetic resonance analysis. C4 was analysed in a 96-well plate format with a deuterated C4 internal standard and liquid-liquid extraction. Validation followed the 2018 Food and Drug Administration guidelines. To assess C4 stability, healthy volunteers (n=12) donated 8 fasted samples each. Samples were incubated at 20 °C for up to 72 h and retrieved, centrifuged, aliquoted and frozen for storage at different time points prior to C4 analysis.

RESULTS

The C4 method demonstrated excellent analytical performance and passed all validation criteria. The method was found to be accurate, precise, free from matrix effects and interference. After 72 h of delayed sample separation, C4 concentration gradually declined by up to 14 % from baseline. However, the change was not significant for up to 12 h.

CONCLUSIONS

We present a robust method of analysing serum C4, offering a convenient alternative to 75SeHCAT for BAD investigation. C4 was found to decline in unseparated blood over time; however, after 12 h the mean change was <5 % from baseline. Our results suggest C4 is suitable for collection from both primary and secondary care prior to gastroenterology referral.

The etiological profile of chronic organic non-bloody diarrhea in India: Emergence of inflammatory bowel disease as a dominant cause

BACKGROUND

Chronic non-bloody diarrhea may be attributed either to functional or organic diseases. The latter category may present with malabsorption syndrome if there is extensive involvement of the small bowel, whereas diseases of the large bowel may only present with diarrhea sans malabsorption. Indian data has predominantly focussed on the etiological spectrum of malabsorption syndrome in adults. The primary aim of the current study was to evaluate etiological spectrum of chronic organic non-bloody diarrhea in India.

METHODS

This prospective observational study was done at a tertiary care hospital in North India. Patients ≥ 18 years presenting with chronic non-bloody diarrhea of > 4 weeks duration were enrolled in the study after exclusion of patients with IBS and anal incontinence.

RESULTS

During the study period of 12 months, 100 patients with chronic organic non-bloody diarrhea were evaluated. A definite etiological diagnosis was made in 97 patients (97%). The mean age of the patients was 48 ± 16.7 years (58% males). The median duration of diarrhea was 5.5 months (interquartile range [IQR] 3.5, 11). Inflammatory bowel disease (IBD) accounted for 45% of the cases making it the predominant cause for organic diarrhea. GI infections and adult-onset celiac disease accounted for 18% and 9% of the cases, respectively. Pancreatic disease, benign or neoplastic, accounted for 6% of the total cases. Notably, gastrointestinal (GI) malignancies manifesting as chronic non-bloody diarrhea were diagnosed in 5% of the patients.

CONCLUSION

Our data suggests a paradigm shift in the etiological spectrum of chronic organic non-bloody diarrhea in India with the emergence of IBD as the predominant cause displacing GI infections.

Canadian Association of Radiologists Gastrointestinal Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Gastrointestinal Expert Panel consists of radiologists, a gastroenterologist, a general surgeon, a family physician, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 20 clinical/diagnostic scenarios, a systematic rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 58 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 85 recommendation statements specific to the adult population across the 20 scenarios. This guideline presents the methods of development and the referral recommendations for dysphagia/dyspepsia, acute nonlocalized abdominal pain, chronic abdominal pain, inflammatory bowel disease, acute gastrointestinal bleeding, chronic gastrointestinal bleeding/anemia, abnormal liver biopsy, pancreatitis, anorectal diseases, diarrhea, fecal incontinence, and foreign body ingestion.

Prevalence of chronic diarrhea and its association with obesity in a Chinese community-based population

BACKGROUND

Epidemiological data on chronic diarrhea in the Chinese population are lacking, and the association between obesity and chronic diarrhea in East Asian populations remains inconclusive. This study aimed to investigate the prevalence of chronic diarrhea and its association with obesity in a representative community-dwelling Chinese population.

METHODS

This cross-sectional study was based on a multistage, randomized cluster sampling involving 3503 residents aged 20-69 years from representative urban and rural communities in Beijing. Chronic diarrhea was assessed using the Bristol Stool Form Scale (BSFS), and obesity was determined based on body mass index (BMI). Logistic regression analysis and restricted cubic splines were used to evaluate the relationship between obesity and chronic diarrhea.

RESULTS

The standardized prevalence of chronic diarrhea in the study population was 12.88%. The average BMI was 24.67 kg/m 2 . Of all the participants, 35.17% (1232/3503) of participants were classified as overweight and 16.13% (565/3503) as obese. After adjustment for potential confounders, individuals with obesity had an increased risk of chronic diarrhea as compared to normal weight individuals (odds ratio = 1.58, 95% confidence interval: 1.20-2.06). A nonlinear association between BMI and the risk of chronic diarrhea was observed in community residents of males and the overall participant group ( P  = 0.026 and 0.017, respectively).

CONCLUSIONS

This study presents initial findings on the prevalence of chronic diarrhea among residents of Chinese communities while offering substantiated evidence regarding the significant association between obesity and chronic diarrhea. These findings offer a novel perspective on gastrointestinal health management.

Transcriptome analysis suggests broad jejunal alterations in Linghu's obesity-diarrhea syndrome: A pilot study

BACKGROUND

Obesity is associated with a significantly increased risk for chronic diarrhea, which has been proposed as Linghu's obesity-diarrhea syndrome (ODS); however, its molecular mechanisms are largely unknown.

AIM

To reveal the transcriptomic changes in the jejunum involved in ODS.

METHODS

In a cohort of 6 ODS patients (JOD group), 6 obese people without diarrhea (JO group), and 6 healthy controls (JC group), high-throughput sequencing and bioinformatics analyses were performed to identify jejunal mucosal mRNA expression alterations and dysfunctional biological processes. In another cohort of 16 ODS patients (SOD group), 16 obese people without diarrhea (SO group), and 16 healthy controls (SC group), serum diamine oxidase (DAO) and D-lactate (D-LA) concentrations were detected to assess changes in intestinal barrier function.

RESULTS

The gene expression profiles of jejunal mucosa in the JO and JC groups were similar, with only 1 differentially expressed gene (DEG). The gene expression profile of the JOD group was significantly changed, with 411 DEGs compared with the JO group and 211 DEGs compared with the JC group, 129 of which overlapped. The enrichment analysis of these DEGs showed that the biological processes such as digestion, absorption, and transport of nutrients (especially lipids) tended to be up-regulated in the JOD group, while the biological processes such as rRNA processing, mitochondrial translation, antimicrobial humoral response, DNA replication, and DNA repair tended to be down-regulated in the JOD group. Eight DEGs (CDT1, NHP2, EXOSC5, EPN3, NME1, REG3A, PLA2G2A, and PRSS2) may play a key regulatory role in the pathological process of ODS, and their expression levels were significantly decreased in ODS patients (P < 0.001). In the second cohort, compared with healthy controls, the levels of serum intestinal barrier function markers (DAO and D-LA) were significantly increased in all obese individuals (P < 0.01), but were higher in the SOD group than in the SO group (P < 0.001).

CONCLUSION

Compared with healthy controls and obese individuals without diarrhea, patients with Linghu's ODS had extensive transcriptomic changes in the jejunal mucosa, likely affecting intestinal barrier function and thus contributing to the obesity and chronic diarrhea phenotypes.

NEDD4 and NEDD4L: Ubiquitin Ligases Closely Related to Digestive Diseases

Protein ubiquitination is an enzymatic cascade reaction and serves as an important protein post-translational modification (PTM) that is involved in the vast majority of cellular life activities. The key enzyme in the ubiquitination process is E3 ubiquitin ligase (E3), which catalyzes the binding of ubiquitin (Ub) to the protein substrate and influences substrate specificity. In recent years, the relationship between the subfamily of neuron-expressed developmental downregulation 4 (NEDD4), which belongs to the E3 ligase system, and digestive diseases has drawn widespread attention. Numerous studies have shown that NEDD4 and NEDD4L of the NEDD4 family can regulate the digestive function, as well as a series of related physiological and pathological processes, by controlling the subsequent degradation of proteins such as PTEN, c-Myc, and P21, along with substrate ubiquitination. In this article, we reviewed the appropriate functions of NEDD4 and NEDD4L in digestive diseases including cell proliferation, invasion, metastasis, chemotherapeutic drug resistance, and multiple signaling pathways, based on the currently available research evidence for the purpose of providing new ideas for the prevention and treatment of digestive diseases.

Biomarkers in inflammatory bowel disease: a practical guide

Inflammatory bowel disease (IBD), comprising ulcerative colitis (UC) and Crohn's disease (CD), is a costly condition in terms of morbidity and healthcare utilization, with an increasing prevalence now approaching 1% in the Western world. Endoscopic assessment of IBD remains the gold standard for diagnosis, evaluation of treatment response and determination of post-operative recurrence, but is expensive and invasive. Biomarkers can facilitate non-invasive disease assessment, with C-reactive protein and faecal calprotectin as the most widely available biomarkers in current clinical practice. This narrative review summarizes the evidence for their use in both UC and CD and offers practical guidance for healthcare providers taking into account the limitations of biomarker interpretation. We present evidence for the future use of novel biomarkers in IBD and discuss how biomarker discovery could deliver the goal of precision medicine in IBD.

Immune checkpoint inhibitor associated diarrhoea

A man in his 80s was undergoing immunotherapy with pembrolizumab, an anti-PD-1 monoclonal antibody, following his diagnosis of adenocarcinoma of primary lung origin. 24 weeks into treatment, the patient reported experiencing loose stools associated with malaise and poor appetite but no further symptoms. This progressed in frequency and a clinical diagnosis of grade 2 immune checkpoint inhibitor colitis was made. Management with oral prednisolone was commenced but symptoms persisted. Common enteric infections had been ruled out, as were coeliac disease and hyperthyroidism. Flexible sigmoidoscopy and colonoscopy results were not in keeping with colitis, having revealed normal looking mucosa. Following this, a faecal elastase level was found to be low. A diagnosis of pembrolizumab-induced pancreatic exocrine insufficiency was made, and stool frequency and consistency swiftly improved following the use of pancreatic enzyme replacement therapy.

Comparison between SeHCAT test and clinical response to cholestyramine in patients with chronic diarrhea and high suspicion of bile acid malabsorption: A single-center prospective study

OBJECTIVES

We aimed to evaluate the clinical response to cholestyramine in patients with functional chronic diarrhea and a high clinical suspicion of bile-acid diarrhea (BAD) investigated with 75-selenium homocholic acid taurine (SeHCAT) test.

METHODS

Adult patients attending our outpatient clinic between January and December 2021 for chronic diarrhea with suspicion of BAD were proposed SeHCAT testing and a therapeutic trial of cholestyramine 4-8 g daily. Clinical response to cholestyramine was evaluated at 1, 3, 6, and 12 months. Clinical and demographic data were analyzed according to SeHCAT test results.

RESULTS

Among the 50 patients with chronic diarrhea and clinical suspicion of BAD, 13 (26.0%) refused either SeHCAT testing or cholestyramine therapy. Finally, 37 patients (31 females, age 44 ± 14 years) agreed to undergo SeHCAT and were started on cholestyramine (median follow-up 14 months [interquartile range 6-16 months]). Initial response to cholestyramine was similar in patients with positive and negative SeHCAT test results, but improved over time in those with a positive test result. Long-term response (100% vs 65.2%, P = 0.02) and necessity of maintenance therapy for symptom control were more common in those with positive SeHCAT test result (71.4% vs 26.1%, P = 0.02). However, response to cholestyramine was also frequent in patients with a negative test result.

CONCLUSIONS

The SeHCAT test accurately identifies patients with BAD who benefit from long-term cholestyramine treatment. Nevertheless, cholestyramine may be also effective in patients with chronic diarrhea but negative SeHCAT test result.

Medicinal grade opium tincture for severe diarrhea: effect revisited in observational study

PURPOSE OF REVIEW

Chronic diarrhea is a common disorder that interferes with normal daily activities and results in poor quality of life. Fecal urgency and incontinence often necessitate clinical consultation, but the pathophysiological mechanisms are difficult to differentiate in a clinical setting. Therefore, drugs targeting the opioid receptors, such as diphenoxylate and loperamide, are typically used, as they reduce both gut motility and secretion.

RECENT FINDINGS

For severe diarrhea, morphine-containing extemporaneous opium tincture drops have recently been reprofiled to a pharmaceutical. The drug is indicated for severe diarrhea in adults when other antidiarrheals do not give sufficient fecal emptying control. The pronounced effect is due to the liquid formulation with rapid onset as a drug dissolution step is avoided. A recent prospective, noninterventional study (CLARIFY) of patients treated with opioid drops demonstrates a rapid and sustained therapeutic effect. Tolerance does not develop for the antidiarrheal effect and no dependence was observed after discontinuation.

SUMMARY

This mini-review discusses the use of opium derivates for treatment of diarrhea, with an emphasis on opium drops as a new medicinal grade opium for the use as additional treatment of severe diarrhea, emphasizing its mechanism of action and evaluation of the risk-benefit ratio in the clinical setting.

Mast cell activation and nutritional disorders in patients with hypermobility

PURPOSE OF REVIEW

Individuals with joint hypermobility disorders are increasingly referred to gastroenterology services for support with the investigation and management of gastrointestinal complaints. Individuals can present with a myriad of complex coexisting diagnoses, the inter-relationship of which is unclear. This review discusses the proposed association between hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorder (HSD) with disorders of mast cell activation and provides an overview of gastrointestinal symptoms and nutritional outcomes in this patient cohort.

RECENT FINDINGS

It is unclear whether a true association between hEDS/HSD and mast cell activation disorders exists. There is a high prevalence of nonspecific gastrointestinal symptoms in individuals with hEDS/HSD and patients may be at risk of macro-nutrient and micro-nutrient deficiencies, although the current evidence base is limited.

SUMMARY

We advocate a pragmatic approach to the investigation and management of gastrointestinal symptoms in patients with hEDS/HSD. This centres on excluding organic pathology, discussing the overlap with disorders of gut-brain interactions, trialling evidence-based therapies targeting individual symptoms, and supporting nutritional deficiencies where present via the least invasive approach. Engagement with a broad multidisciplinary team is also important to support the holistic needs of this patient cohort.

Evaluation of non-invasive diagnostic tools for diarrhea: a systematic review of point-of-care tests and biomarkers

Background

Diarrhea is a prevalent condition affecting millions worldwide. However, current standard diagnostic methods have many drawbacks. This review examines various non-invasive point-of-care (POC) tests and biomarkers aiding rapid diagnosis of diarrhea from different causes.

Methods

PubMed, PubMed Central, ScienceDirect, Cochrane Library, and Google Scholar were searched from 2013 to present for relevant literature. Two reviewers independently assessed included studies' quality using the Critical Appraisal Skills Programme (CASP) checklist.

Results

The search yielded 1453 studies, of which 39 were included after screening and applying eligibility criteria. Polymerase chain reaction (PCR) was the POC test in 25 studies, providing consistent sensitivity and specificity. For biomarkers, C-reactive protein (CRP), fecal calprotectin, and procalcitonin offered high sensitivity and specificity for conditions like acute pediatric diarrhea, microscopic colitis, and inflammatory diarrhea, respectively.

Conclusion

PCR proved the ideal POC test for rapid diarrhea diagnosis, while the procalcitonin biomarker helps differentiate inflammatory from non-inflammatory diarrhea. Other reviewed tools also demonstrated promising diagnostic performance, though improvements in sensitivity, specificity, and usability are still needed.

[Bile Acid Diarrhea]

Diarrhea is a very common gastrointestinal symptom, and the presence of higher concentrations of bile acid in the colon leads to bile acid diarrhea (BAD). In BAD patients, a portion of bile from the small intestine that is normally controlled by enterohepatic circulation is present at a high concentration in the lumen of the large intestine, resulting in increased motility and secretion of the large intestine. The prevalence of BAD is estimated to be 1-2% of the general population, and it comprises one-third of the instances of diarrhea-predominant irritable bowel syndrome. The clinical symptoms of BAD include chronic diarrhea, increased frequency of defecation, urgency to defecate, fecal incontinence, and cramping abdominal pain. The pathophysiology of BAD has not yet been fully elucidated. However, recent studies have reported increased intestinal permeability, shortened intestinal transit time, and changes in the intestinal microbial community to be the possible causes of BAD. Although fecal and serum bile acid tests are widely used for diagnosis, new test methods that are non-invasive, inexpensive, and have high sensitivity and specificity are needed at various institutions to facilitate the diagnosis. The selenium homo-tauro-cholic acid (SeHCAT) test is the gold standard for BAD diagnosis and severity assessment. The validation of several other serum markers, such as 7-hydroxy-4-cholesten-3-one (serum 7αC4) and the fibroblast growth factor 19 (FGF19) for use in clinical practice is ongoing. Although bile acid sequestrants are the mainstay of treatment, the development of drugs that are more effective and have better compliance is required. Farnesoid X receptor (FXR) agonists are showing promising results.

Practical management of disease-related manifestations and drug toxicities in patients with multiple myeloma

Multiple myeloma (MM) is a very heterogeneous disease with multiple symptoms and clinical manifestations. MM affects mainly elderly patients and is difficult to manage in the presence of comorbidities, polypharmacy, frailty and adverse events of disease-targeted drugs. The rapid changes in MM treatment resulting from constant innovations in this area, together with the introduction of numerous new drugs with distinct mechanisms of action and toxicity profiles, have led to an increased complexity in the therapeutic decision-making and patient management processes. The prolonged exposure to novel agents, sometimes in combination with conventional therapies, makes this management even more challenging. A careful balance between treatment efficacy and its tolerability should be considered for every patient. During treatment, a close monitoring of comorbidities, disease-related manifestations and treatment side effects is recommended, as well as a proactive approach, with reinforcement of information and patient awareness for the early recognition of adverse events, allowing prompt therapeutic adjustments. In this review, we discuss various issues that must be considered in the treatment of MM patients, while giving practical guidance for monitoring, prevention and management of myeloma-related manifestations and treatment-related toxicities.

Characterization of primary small intestinal lymphoma: a retrospective study based on double balloon endoscopy

BACKGROUND

The diagnosis of primary small intestinal lymphoma (PSIL) is difficult. This study aimed to evaluate the clinical, radiological and endoscopic characteristics of PSIL and provide clue for diagnosis.

METHODS

A total of 30 patients diagnosed with PSIL who underwent double balloon endoscopy (DBE) in the First Affiliated Hospital of Zhejiang University were retrospectively analyzed. Clinical, radiological and endoscopic data were collected. Univariate analysis was used to determine significant indicators for differentiating three main subtypes of PSIL. Cox regression analysis was performed to assess the risk factors for survival.

RESULTS

In this study, 10 patients were pathologically diagnosed as diffuse large B-cell lymphoma (DLBCL), 11 were indolent B-cell lymphoma (BCL) and 9 were T-cell lymphoma (TCL). Compared with DLBCL patients, the body mass index (BMI) of TCL patients was significantly lower (p = 0.004). Meanwhile, compared with patients with DLBCL, the patients with indolent BCL had lower levels of C-reactive protein, lactate dehydrogenase (LDH), fibrinogen and D-Dimer (p = 0.004, p = 0.004, p = 0.006, and p = 0.002, respectively), and lower proportion of thicker intestinal wall and aneurysmal dilation in CT scan (p = 0.003 and p = 0.020, respectively). In terms of ulcer morphology, patients with DLBCL had significantly higher proportion of deep ulcers than patients with indolent BCL (p = 0.020, respectively). Cox regression analysis showed that drink (p = 0.034), concomitant colonic ulcers (p = 0.034) and elevated LDH (p = 0.043) are risk factors for mortality in patients with PSIL.

CONCLUSIONS

This study provides clinical characteristics of patients with PSIL. Thicker intestinal wall and aneurismal dilation detected on CT scan and deeper ulcer on DBE examination helps to establish a diagnosis of DLBCL.

[Efficacy of navel application of Jianpiwenyang Gel for chronic diarrhea of spleen and stomach weakness type: a randomized controlled trial and analysis of the mechanism]

OBJECTIVE

To investigate the efficacy of Jianpiwenyang Gel (SSWYG) for treating chronic diarrhea and explore its therapeutic mechanism.

METHODS

Eighty patients with chronic diarrhea of spleen and stomach weakness type were randomized into two groups for interventions with lifestyle adjustment and treatment with bifid triple viable capsules (control group, n=40) or naval application with SSWYG (treatment group, n=40) for one week, after which symptoms of chronic diarrhea were evaluated. The Chinese medicine system pharmacology analysis platform (TCMSP), GeneCards, NCBI, OMIM database and GEO database (GSE14841) were used to obtain the active ingredients and target proteins of SSWYG and chronic diarrhea-related targets. The key targets were obtained by topological analysis for Gene Ontology (GO) and KEGG analyses. The affinity and binding characteristics of SSWYG for specific targets were verified by molecular docking using AutoDock software.

RESULTS

In both groups, gastrointestinal symptom rating scale (GSRS), Bristol Scale and TCM syndrome scores significantly improved after the treatments (P < 0.05), and better effects were observed in the treatment group (P < 0.05). Sixtyeight targets of SSWYG in treating chronic diarrhea were obtained, and 33 most probable ones were screened out by topological analysis. GO and KEGG analyses identified several chronic diarrhea-related pathways including the TNF and IL-17 pathways. Molecular docking study showed good affinity of the core components of SSWYG for the key targets CASP3, JNK, IL1B, IL6, and AKT1. JUN and CASP3 had the lowest binding energy and the highest stable binding energy with multiple major active ingredients of SSWYG.

CONCLUSION

SSWYG can significantly improve clinical symptoms of chronic diarrhea possibly by regulating the TNF and IL-17 as well as other pathways via CASP3 and JUN, suggesting a complex therapeutic mechanism of SSWYG involving multiple ingredients and targets and coordinated regulation of multiple pathways.

Food intolerance related to gastrointestinal symptoms amongst adults living with bile acid diarrhoea: A cross-sectional study

BACKGROUND

The role of food in managing bile acid diarrhoea (BAD) is poorly understood. The present study explored the prevalence of food intolerance amongst adults with BAD.

METHODS

The study comprised a cross-sectional survey of adults with BAD determined by the 75 selenium homotaurocholic acid test (SeHCAT) living in the UK. Participants anonymously completed an online questionnaire on 39 food items. Frequency of food in general affecting BAD symptoms, as well as frequencies of diarrhoea, abdominal pain, bloating, flatulence and consequential food avoidance after food item ingestion, were assessed. Food group avoidance was also assessed.

RESULTS

There were 434 participants who completed the questionnaire between April and May 2021 of whom 80% reported moderate to severe chronic diarrhoea. Food intolerances were reported by 88.0% (95% confidence interval [CI] = 84.6-90.9) of participants. Diarrhoea was reported most frequently after take-away food, fish and chips, creamy sauces, cream and large quantities of fruit (range 41.0%-33.6%). Lowest frequencies were for potato, avocado, mango, watermelon and pear (range 3.7%-7.4%) for the foods listed in the questionnaire. Similar trends were found for abdominal pain, bloating, flatulence and consequential food avoidance. Symptom-triggering within 30 min of ingestion was more prevalence than after 30 min for almost all foods. Food group avoidance was highest for fatty foods (81.2%; 95% CI = 77.8-85.3) followed by dairy (53.9%; 95% CI = 49.1-58.7).

CONCLUSIONS

Perceived food intolerance amongst adults with BAD and persisting diarrhoeal symptoms is high. Important triggers were meals with a higher fat content and higher-fat dairy products. Diets amongst those with persisting diarrhoeal symptoms may be overly restrictive.

Bile Acid Diarrhea: From Molecular Mechanisms to Clinical Diagnosis and Treatment in the Era of Precision Medicine

Bile acid diarrhea (BAD) is a multifaceted intestinal disorder involving intricate molecular mechanisms, including farnesoid X receptor (FXR), fibroblast growth factor receptor 4 (FGFR4), and Takeda G protein-coupled receptor 5 (TGR5). Current diagnostic methods encompass bile acid sequestrants (BAS), 48-h fecal bile acid tests, serum 7α-hydroxy-4-cholesten-3-one (C4), fibroblast growth factor 19 (FGF19) testing, and 75Selenium HomotauroCholic acid test (75SeHCAT). Treatment primarily involves BAS and FXR agonists. However, due to the limited sensitivity and specificity of current diagnostic methods, as well as suboptimal treatment efficacy and the presence of side effects, there is an urgent need to establish new diagnostic and treatment methods. While prior literature has summarized various diagnostic and treatment methods and the pathogenesis of BAD, no previous work has linked the two. This review offers a molecular perspective on the clinical diagnosis and treatment of BAD, with a focus on FXR, FGFR4, and TGR5, emphasizing the potential for identifying additional molecular mechanisms as treatment targets and bridging the gap between diagnostic and treatment methods and molecular mechanisms for a novel approach to the clinical management of BAD.

Metabolic and Nutritional Issues after Lower Digestive Tract Surgery: The Important Role of the Dietitian in a Multidisciplinary Setting

Many patients undergo small bowel and colon surgery for reasons related to malignancy, inflammatory bowel disease (IBD), mesenteric ischemia, and other benign conditions, including post-operative adhesions, hernias, trauma, volvulus, or diverticula. Some patients arrive in the operating theatre severely malnourished due to an underlying disease, while others develop complications (e.g., anastomotic leaks, abscesses, or strictures) that induce a systemic inflammatory response that can increase their energy and protein requirements. Finally, anatomical and functional changes resulting from surgery can affect either nutritional status due to malabsorption or nutritional support (NS) pathways. The dietitian providing NS to these patients needs to understand the pathophysiology underlying these sequelae and collaborate with other professionals, including surgeons, internists, nurses, and pharmacists. The aim of this review is to provide an overview of the nutritional and metabolic consequences of different types of lower gastrointestinal surgery and the role of the dietitian in providing comprehensive patient care. This article reviews the effects of small bowel resection on macronutrient and micronutrient absorption, the effects of colectomies (e.g., ileocolectomy, low anterior resection, abdominoperineal resection, and proctocolectomy) that require special dietary considerations, nutritional considerations specific to ostomized patients, and clinical practice guidelines for caregivers of patients who have undergone a surgery for local and systemic complications of IBD. Finally, we highlight the valuable contribution of the dietitian in the challenging management of short bowel syndrome and intestinal failure.

Network Pharmacology and Intestinal Microbiota Analysis Revealing the Mechanism of Punicalagin Improving Bacterial Enteritis

BACKGROUND

The Chinese medicine punicalagin (Pun), the most important active ingredient in pomegranate peel, has significant bacteriostatic and anti-inflammatory properties. The potential mechanisms of Pun for bacterial enteritis, however, are unknown.

OBJECTIVE

The goal of our research is to investigate the mechanism of Pun in the treatment of bacterial enteritis using computer-aided drug technology, as well as to investigate the intervention effect of Pun on mice with bacterial enteritis using intestinal flora sequencing.

METHODS

The targets of Pun and Bacterial enteritis were obtained by using the specific database, and cross-targets were screened among these targets, followed by PPI and enrichment analysis of the targets. Furthermore, the degree of binding between Pun and key targets was predicted through molecular docking. After successfully establishing the bacterial enteritis model in vivo, mice were randomly assigned to groups. They were treated for 7 days, the symptoms were observed daily, and the daily DAI and body weight change rate were calculated. Following administration, the intestinal tissue was removed, and the contents were separated. The tight junction protein expression was detected in the small intestine by the immunohistochemical method; ELISA and Western Blot (WB) were performed to detect the expressions of tumor necrosis factor-α (TNF-α) and interleukin- 6 (IL-6) in the serum and intestinal wall of mice. The 16S rRNA sequence was used to determine the composition and diversity of the intestinal flora of mice.

RESULTS

In total, 130 intersection targets of Pun and disease were screened by network pharmacology. The enrichment analysis showed cross genes were closely related and enriched in the cancer regulation and the TNF signal pathway. The active components of Pun could specifically bind to the core targets TNF, IL-6, etc., determined from molecular docking results. In vivo experiment results showed that the symptoms in the PUN group mice were alleviated, and the expression levels of TNF-α and IL-6 were significantly reduced. A Pun can cause substantial changes in the intestinal flora of mice in terms of structure and function.

CONCLUSION

Pun plays a multi-target role in alleviating bacterial enteritis by regulating intestinal flora.

The comparison of an accessible C-shaped partial stapled hemorrhoidopexy (C-PSH) versus circular stapled hemorrhoidopexy (CSH) in patients with grade IV hemorrhoids: a retrospective cohort study

OBJECTIVES

The objectives of this study were to present an accessible C-shaped partial stapled hemorrhoidopexy (C-PSH) in the treatment of grade IV hemorrhoids and to assess long-term outcomes of this technique compared with circular stapled hemorrhoidopexy (CSH).

METHODS

Conventional CSH kits combined with an intestinal spatula were used for performing C-PSH. A total of 256 patients with grade IV hemorrhoids referred to Hangzhou Third People's Hospital between January 2016 and June 2017 were obtained: 122 (47.7%) with C-PSH, and 134 (52.3%) with CSH. After propensity score matching, 222 patients (111 in C-PSH group and 111 in CSH group) were ultimately analyzed. The primary outcome was the five-year recurrence rate of hemorrhoids. Secondary outcomes included intraoperative outcomes, postoperative outcomes and complications.

RESULTS

The operative time in the C-PSH group was slightly longer than that in the CSH group (p < 0.01). The vertical length of rectal mucosa specimen in the C-PSH group was shorter than that in the CSH group (p < 0.01). Compared with the CSH group, fecal urgency incidence and numeric rating scale (NRS) score at first defecation were lower in the C-PSH group (p < 0.05). Major complication rate in the CSH group was higher than that in the C-PSH group (p = 0.03). Five-year recurrence rate between the C-PSH group and CSH group was comparable (p > 0.05). Multivariate Cox regression analysis revealed that constipation was an independent prognostic factor for hemorrhoidal recurrence.

CONCLUSIONS

The accessible C-PSH seems to be a safe and effective technique in managing grade IV hemorrhoids. It has advantages in alleviating postoperative pain at first defecation, fecal urgency and major complications compared with CSH. It could be an alternative technique in the treatment of grade IV hemorrhoids.

The Importance of Considering Common Variable Immunodeficiency in Patients With Chronic Diarrhea

Chronic diarrhea poses a diagnostic challenge due to its diverse etiology, encompassing various gastrointestinal disorders. This case report emphasizes the clinical significance of considering common variable immunodeficiency (CVID) as a potential underlying cause in a patient presenting with chronic diarrhea. In this case study, we describe a 36-year-old female with a 9-year history of chronic diarrhea, recurrent sinopulmonary infections, and weight loss for 3 years, where previous evaluations failed to yield a diagnosis. This case underscores the diagnostic hurdles faced by healthcare professionals, often causing a delay in identifying fewer common conditions like immunodeficiency syndromes. Early recognition of CVID is crucial, enabling timely intervention with immunoglobulin replacement therapy, markedly enhancing patients' quality of life and averting complications. This report highlights the necessity for a comprehensive evaluation of non-responsive chronic diarrhea cases and raises awareness about CVID as an essential consideration, facilitating precise diagnoses and tailored treatments.

Diagnosis and management of pancreatic insufficiency in patients with gastrectomy due to cancer or gastric ulcers: a virtual roundtable expert discussion

INTRODUCTION

Pancreatic exocrine insufficiency (PEI) is common after gastric resection for cancer or ulcers but is under-recognized and undertreated. Although pancreatic enzyme replacement therapy (PERT) is the mainstay of PEI management, robust evidence supporting its use after gastric surgery is limited.

AREAS COVERED

In the absence of guideline recommendations specific for patients with pancreatic insufficiency after gastrectomy, a panel of experts from different geographical regions convened in a virtual meeting to discuss their approach to patient management.

EXPERT OPINION

Pancreatic insufficiency after gastrointestinal surgery is not a simple post-surgical complication as several factors contribute to its development. Although the pancreas is unimpaired after gastrectomy, it cannot function normally in the altered environment. Pancreatic insufficiency can be challenging to diagnose in gastrectomy patients due to nonspecific symptoms and the absence of a simple diagnostic test. Fecal elastase appears to be the default test, although it is not sufficiently sensitive nor reliable for diagnosing or monitoring PEI. Patients with maldigestion symptoms after gastrectomy are treated pragmatically: those with clinical suspicion of pancreatic insufficiency receive a trial of PERT and are monitored for symptom improvement. There is a clear need for high-quality evidence from clinical trials to guide the management of this patient population.

Diagnosis and treatment of post-cholecystectomy diarrhoea

The incidence of cholecystitis is relatively high in developed countries and may usually be attributed to gallstones, the treatment for which involves complete surgical removal of the gallbladder (cholecystectomy). Bile acids produced following cholecystectomy continue to flow into the duodenum but are poorly absorbed by the colon. Excessive bile acids in the colon stimulate mucosal secretion of water and electrolytes leading, in severe cases, to diarrhoea. Bile acid diarrhoea (BAD) is difficult to diagnose, requiring a comprehensive medical history and physical examination in combination with laboratory evaluation. The current work reviews the diagnosis and treatment of BAD following cholecystectomy.

Multiple immunoassay interference in a patient with falsely elevated calcitonin

Calcitonin (CT) is a diagnostic and follow-up marker of medullary thyroid carcinoma. Heterophile antibodies (HAbs) may interfere during immunometric assay measurements and result in falsely high CT levels and different markers. A 50-year-old female patient was referred to our institution for elevated CT levels (3,199 pg/mL [0-11,5]). Physical examination and thyroid ultrasonography show no thyroid nodules. Because of the discrepancy between the clinical picture and the laboratory results, various markers and hormones were examined to determine whether there was any interference in the immunometric assay. Thyroglobulin (Tg) and Adrenocorticotropic hormone (ACTH) levels were also found inaccurately elevated. After precipitation with polyethylene glycol, CT, Tg, and ACTH levels markedly decreased, showing macro-aggregates. Also, serial dilutions showed non-linearity in plasma concentrations. Additionally, CT samples were pretreated with a heterophilic blocking tube before measuring, and the CT level decreased to < 0.1 pg/mL, suggesting a HAb presence. Immunoassay interference should be considered when conflicting laboratory data are observed. This may help reduce the amount of unnecessary laboratory and imaging studies and prevent patients from complex diagnostic procedures.

Severe chronic diarrhoea caused by hereditary transthyretin amyloidosis

Amyloidosis includes a heterogeneous group of diseases caused by the extracellular deposition of insoluble fibrillar proteins, leading to multiple organ dysfunction and a poor life expectancy. In the early stages of amyloidosis, gastrointestinal (GI) symptoms are uncommon. We describe a rare case of hereditary transthyretin amyloidosis (ATTRv) with involvement of the heart, nervous system and GI tract. A man in his 60s was hospitalised due to chronic diarrhoea, orthostatic hypotension, malabsorption and weight loss. An organic origin for the diarrhoea was suspected, but the most common causes were ruled out. The review of GI biopsies and an abdominal fat aspirate confirmed the diagnosis of amyloidosis. The diagnosis of ATTRv amyloidosis with GI presentation is challenging, especially in the early stages, and misdiagnosis is common. The recent approval of therapies emphasises the importance of early diagnosis to prevent irreversible organ damage.

Persistent and new-onset symptoms after cholecystectomy in patients with uncomplicated symptomatic cholecystolithiasis: A post hoc analysis of 2 prospective clinical trials

BACKGROUND

Laparoscopic cholecystectomy is the gold standard for treating biliary colic in patients with gallstones, but post-cholecystectomy abdominal pain is commonly reported. This study investigates which symptoms are likely to persist and which may develop after a cholecystectomy.

METHODS

Patients from 2 previous prospective trials who underwent laparoscopic cholecystectomy for symptomatic cholecystolithiasis were included. Patients completed questionnaires on pain and gastrointestinal symptoms before surgery and at 6 months follow-up. The prevalence of persistent and new-onset abdominal symptoms was evaluated.

RESULTS

A total of 820 patients received cholecystectomy and were included, 75.4% female (n = 616/820) mean age 49.4 years (standard deviation 13.7). At baseline, 74.1% (n = 608/820) of patients met all criteria for biliary colic. Cholecystectomy successfully resolved biliary colic in 94.8% (n = 327/345) of patients, but 36.5% (n = 299/820) of patients reported persistent abdominal pain after 6 months of follow-up. The prevalence of most abdominal symptoms reduced significantly. Symptoms such as flatulence (17.8%, n = 146/820) or restricted eating (14.5%, n = 119/820) persisted most often. New-onset symptoms were frequent bowel movements (9.6%, n = 79/820), bowel urgency (8.5%, n = 70/820), and new-onset diarrhea (8.4%, 69/820).

CONCLUSION

Postcholecystectomy symptoms are mainly flatulence, frequent bowel movements, and restricted eating. Newly reported symptoms are mainly frequent bowel movements, bowel urgency, and diarrhea. The present findings give clinical guidance in informing, managing, and treating patients with symptoms after cholecystectomy.

Nutrition Considerations in Patients with Functional Diarrhea

PURPOSE

Functional diarrhea (FD) is a functional gastrointestinal disorder that affects a great percentage of the population and has damaging nutritional and psychological effects. In this review, evidence has been assessed and analyzed to provide nutrition considerations and recommendations for patients with functional diarrhea.

RECENT FINDINGS

The traditional irritable bowel syndrome (IBS) diet, the low FODMAP diet, and general recommendations for diarrhea have been established as interventions for FD. Additionally, nutrition outcomes such as vitamin and mineral deficiencies, hydration levels, and mental health status should be at the forefront of assessment. The importance of medical management of FD and IBS-D is established, with many existing evidence-based recommendations and approved medications available. Nutrition management of FD from a registered dietitian/dietitian nutritionist, from symptom control to dietary advice, is imperative. There are no "one-size-fits-all" approaches to nutrition management of FD, but there is promising literature that can shape personalized nutrition interventions from a registered dietitian.

Approach to Diarrhea

Diarrhea is a common complaint in primary care offices. It affects the patient's quality of life and increases health care resource utilization. Although most cases of diarrhea are acute and self-limiting, there are multiple causes that can lead to serious morbidity and mortality. Likewise, chronic diarrhea can be a sign of a more serious condition and requires thoughtful evaluation. Ultimately, primary care physicians must take an evidence-based and comprehensive approach to diarrhea to appropriately apply health care resources in the interest of patient care.

A Case of Pancreatic Neuroendocrine Tumor With Extensive Skeletal Metastases Detected on 68Ga-DOTANOC PET-CT

Neuroendocrine tumors (NETs) are a rather uncommon cause of chronic non-bloody diarrhea and are therefore often left undiagnosed for prolonged periods of time. In this case, a 46-year-old man was inappropriately treated with antibiotics for months by various doctors, and by the time the diagnosis of NET was made, the tumor had already metastasized to the entire skeleton. The patient refused surgery and was started on octreotide, which resolved his diarrhea.

A protease activity-based machine-learning approach as a complementary tool for conventional diagnosis of diarrhea-predominant irritable bowel syndrome

Irritable bowel syndrome (IBS) has no clinically accepted biomarkers even though it affects a large number of individuals worldwide. To address this lack of understanding, we evaluated peptidase activity in fecal samples from 35 patients with diarrheal IBS without symptom exacerbation (IBS-n) and 35 healthy subjects using a library of 384 fluorescent enzymatic substrate probes. IBS-n patients had high trypsin-like peptidase activity for cleavage of C-terminal lysine and arginine residues and low elastase-like activity for cleavage of C-terminal serine and glycine residues. These fluorescent probe library data, together with diagnostic machine-learning techniques, were able to accurately predict IBS-n. This approach can be used to diagnose diseases where no clinically accepted biomarkers exist, in which fecal enzyme activity is altered and also suggests that the development of new therapies targeting enzyme activities is possible.

Microscopic Colitis: Pathogenesis and Diagnosis

Microscopic colitis is a type of inflammatory bowel disease and is classified as either collagenous colitis or lymphocytic colitis. The typical presentation is chronic watery diarrhea. The disease occurs more frequently in women aged 60-65 years and is increasing in incidence. The pathophysiology of microscopic colitis remains poorly understood and has not been well-described with possible several pathogeneses. To date, the diagnosis of microscopic colitis depends on histological tissue obtained during colonoscopy. Other non-invasive biomarkers, such as inflammatory markers and fecal biomarkers, have been studied in microscopic colitis, but the results remains inconclusive. The approach to chronic diarrhea is important and being able to differentiate chronic diarrhea in patients with microscopic colitis from other diseases, such as inflammatory bowel disease, functional diarrhea, and malignancy, by using non-invasive biomarkers would facilitate patient management. The management of microscopic colitis should be based on each individual's underlying pathogenesis and involves budesonide, bile acid sequestrants, or immunosuppressive drugs in refractory cases. Cigarette smoking and certain medications, especially proton pump inhibitors, should be eliminated, when possible, after the diagnosis is made.

Common gastrointestinal drug-drug interactions in geriatrics and the importance of careful planning

INTRODUCTION

Polypharmacy, which uses multiple medications to treat chronic illnesses, is common among elderly patients. However, it can lead to drug interactions, especially with gastrointestinal (GI) medicines that are extensively used. These drug interactions can have severe consequences and pose a significant challenge to healthcare providers. Therefore, it is crucial to identify the underlying mechanisms of these interactions and develop strategies to minimize medication errors.

AREAS COVERED

We analyzed databases on GI illnesses common in older adults, including GERD, peptic ulcer disease, IBS, IBD, constipation, and diarrhea. Our research identified noteworthy drug interactions and utilized major electronic databases such as USFDA, PubMed, Scopus, and Google Scholar until 15 May 202315 May 2023, along with a review of reference lists.

EXPERT OPINION

Aging can affect how the body processes drugs, leading to an increased risk of drug interactions. Therefore, healthcare professionals must carefully evaluate a patient's medical history and health condition to design personalized treatment plans.

Gastrointestinal Tract Considerations: Part II: How Should a Rheumatologist Best Manage Common Lower Gastrointestinal Tract Complaints in Systemic Sclerosis?

Lower gastrointestinal (GI) symptoms are a frequently encountered problem for clinicians managing patients with systemic sclerosis. The current management practices are focused on the treatment of symptoms with little information available on how to use GI investigations in daily practice. This review demonstrates how to integrate the objective assessment of common lower GI symptoms into clinical care with the aim of guiding clinical decision making. Understanding the type of abnormal GI function that is affecting a patient and determining which parts of the gut are impacted can help clinicians to target therapy more precisely.

Differential Diagnosis of Chronic Diarrhea: An Algorithm to Distinguish Irritable Bowel Syndrome With Diarrhea From Other Organic Gastrointestinal Diseases, With Special Focus on Exocrine Pancreatic Insufficiency

Chronic diarrhea, defined as diarrhea persisting for more than 4 weeks, affects up to 5% of the population regardless of patient age, sex, race, or socioeconomic status. The impact on patient health and quality of life is substantial, and diagnosis and management of these patients have significant economic consequences for health care services. The differential diagnosis of chronic diarrhea is broad, with etiologies including infections, endocrinopathies, maldigestive/malabsorptive conditions, and disorders of gut-brain interaction. The considerable overlap of symptoms across this spectrum makes accurate diagnosis problematic and may lead to delays in diagnosis or misdiagnosis. In this narrative review, we consider the differential diagnosis of chronic diarrhea, focusing on irritable bowel syndrome with diarrhea and exocrine pancreatic insufficiency, two conditions that may present similarly but have very different underlying causes and require significantly different management strategies. We outline a 4-step diagnostic strategy and propose a straightforward algorithm to assist in efficiently differentiating irritable bowel syndrome from exocrine pancreatic insufficiency and other causes of chronic diarrhea. We anticipate that these aids will improve diagnostic accuracy, which ultimately should lead to improvements in patients' health-related quality of life and reduce the societal burden on health care services.

A case of septic shock due to delayed diagnosis of Cryptosporidium infection after liver transplantation

BACKGROUND

Cryptosporidium is recognized as a significant pathogen of diarrhea disease in immunocompromised hosts, and studies have shown that Cryptosporidium infection is high in solid organ transplantation (SOT) patients and often has serious consequences. Because of the lack of specificity of diarrheasymptoms cased by Cryptosporidium infection, it is rarely reported in patients undergoing liver transplantation (LT). It frequently delays diagnosis, coming with severe consequences. In clinical work, diagnosing Cryptosporidium infection in LT patients is also complex but single, and the corresponding anti-infective treatment regimen has not yet been standardized. A rare case of septic shock due to a delayed diagnosis of Cryptosporidium infection after LT and relevant literature are discussed in the passage.

CASE PRESENTATION

A patient who had received LT for two years was admitted to the hospital with diarrhea more than 20 days after eating an unclean diet. After failing treatment at a local hospital, he was admitted to Intensive Care Unit after going into septic shock. The patient presented hypovolemia due to diarrhea, which progressed to septic shock. The patient's sepsis shock was controlled after receiving multiple antibiotic combinations and fluid resuscitation. However, the persistent diarrhea, as the culprit of the patient's electrolyte disturbance, hypovolemia, and malnutrition, was unsolved. The causative agent of diarrhea, Cryptosporidium infection, was identified by colonoscopy, faecal antacid staining, and blood high-throughput sequencing (NGS). The patient was treated by reducing immunosuppression and Nitazoxanide (NTZ), which proved effective in this case.

CONCLUSION

When LT patients present with diarrhea, clinicians should consider the possibility of Cryptosporidium infection, in addition to screening for conventional pathogens. Tests such as colonoscopy, stool antacid staining and blood NGS sequencing can help diagnose and treat of Cryptosporidium infection early and avoid serious consequences of delayed diagnosis. In treating Cryptosporidium infection in LT patients, the focus should be on the patient's immunosuppressive therapy, striking a balance between anti-immunorejection and anti-infection should be sought. Based on practical experience, NTZ therapy in combination with controlled CD4 + T cells at 100-300/mm³ was highly effective against Cryptosporidium without inducing immunorejection.

The analysis of gut microbiota in patients with bile acid diarrhoea treated with colesevelam

Introduction

Bile acid diarrhoea (BAD) is a common disorder that results from an increased loss of primary bile acids and can result in a change in microbiome. The aims of this study were to characterise the microbiome in different cohorts of patients with BAD and to determine if treatment with a bile acid sequestrant, colesevelam, can alter the microbiome and improve microbial diversity.

Materials and methods

Patients with symptoms of diarrhoea underwent 75-selenium homocholic acid (75SeHCAT) testing and were categorised into four cohorts: idiopathic BAD, post-cholecystectomy BAD, post-operative Crohn’s disease BAD and 75SeHCAT negative control group. Patients with a positive 75SeHCAT (&lt;15%) were given a trial of treatment with colesevelam. Stool samples were collected pre-treatment, 4-weeks, 8-weeks and 6–12 months post-treatment. Faecal 16S ribosomal RNA gene analysis was undertaken.

Results

A total of 257 samples were analysed from 134 patients. α-diversity was significantly reduced in patients with BAD and more specifically, in the idiopathic BAD cohort and in patients with severe disease (SeHCAT &lt;5%); p &lt; 0.05. Colesevelam did not alter bacterial α/β-diversity but patients who clinically responded to treatment had a significantly greater abundance of Fusobacteria and Ruminococcus, both of which aid in the conversion of primary to secondary bile acids.

Conclusion

This is the first study to examine treatment effects on the microbiome in BAD, which demonstrated a possible association with colesevelam on the microbiome through bile acid modulation in clinical responders. Larger studies are now needed to establish a causal relationship with colesevelam and the inter-crosstalk between bile acids and the microbiome.

What is the significance of a faecal elastase-1 level between 200 and 500μg/g?

Background

Pancreatic exocrine insufficiency is a cause of malabsorption. It is generally diagnosed if faecal elastase-1 (FE-1) levels are below 200 µg/g. Pancreatic function is assumed to be normal when faecal elastase levels are >500 µg/g. The significance of faecal elastase levels above 200 µg/g but less than 500 µg/g is unclear.

Methods

This retrospective study reports the response to treatment in patients who had an FE-1 level between 200 and 500 µg/g.

Results

Of these 82 patients, 28 were offered pancreatic enzyme replacement therapy (PERT). A clinical response, defined as an improvement in their initial symptoms after commencing PERT, was seen in 20 patients (71%), 7 with potentially predisposing conditions and 13 with functional diarrhoea. PERT particularly abolished or improved diarrhoea, steatorrhoea and flatulence.

Conclusion

Clinicians should, therefore, be aware that a trial of PERT given to patients with FE-1 levels between 200 and 500 µg/g may lead to improvement in gastrointestinal symptoms.

Gut microbiota alteration after cholecystectomy contributes to post-cholecystectomy diarrhea via bile acids stimulating colonic serotonin

Post-cholecystectomy diarrhea (PCD) is highly prevalent among outpatients with cholecystectomy, and gut microbiota alteration is correlated with it. However, how and to what extent changed fecal bacteria contributes to diarrhea are still unrevealed. Humanized gut microbiome mice model by fecal microbiota transplantation was established to explore the diarrhea-inducible effects of gut microbiota. The role of microbial bile acids (BAs) metabolites was identified by UPLC/MS and the underlying mechanisms were investigated with selective inhibitors and antagonists as probes. These mice transplanted with fecal microbiome of PCD patients (PCD mice) exhibited significantly enhanced gastrointestinal motility and elevated fecal water content, compared with these mice with fecal microbiome of NonPCD patients and HC. In analyzing gut microbiota, tryptophan metabolism was enriched in PCD microbiome. In addition, overabundant serotonin in serum and colon, along with elevated biosynthesis gene and reduced reuptake gene, and highly expressed 5-HT receptors (5-HTRs) in colon of PCD mice were found, but not in small intestine. Notably, diarrheal phenotypes in PCD mice were depleted by tryptophan hydroxylase 1 inhibitor (LX1606) and 5-HTRs selective antagonists (alosetron and GR113808). Furthermore, increased microbial secondary BAs metabolites of DCA, HDCA and LCA were revealed in feces of PCD mice and they were found responsible for stimulating 5-HT level in vitro and in vivo. Intriguingly, blocking BAs-conjugated TGR5/TRPA1 signaling pathway could significantly alleviate PCD. In conclusion, altered gut microbiota after cholecystectomy contributes to PCD by promoting secondary BAs in colon, which stimulates colonic 5-HT and increases colon motility.

Microscopic colitis in Northern Ireland: an updated clinicopathological audit and assessment of compliance with European guidelines

AIM

We previously reported the first population-based study of the epidemiology of microscopic colitis in Northern Ireland. The aim of the current study is to provide updated data on incidence, diagnostic methods and clinicopathological associations, following dissemination of the previous report. A further aim was to compare the findings against relevant recommendations from the 2020 European guidelines.

METHOD

Study cases were identified via the Belfast Health and Social Care Trust pathology laboratory system for new cases of collagenous colitis or lymphocytic colitis diagnosed from 2017 to 2020 inclusive. Demographic and clinical information was collated from electronic healthcare records.

RESULTS

Two hundred and seventeen new diagnoses of microscopic colitis were made between 2017 and 2020, comprising 89 (41%) collagenous colitis and 128 (59%) lymphocytic colitis. The overall incidence of microscopic colitis, expressed per 100,000 adult population, ranged from 7.6 to 11.5 (5.9 to 9.0 per 100,000 total population). The 2019 peak of 11.5 cases per 100,000 adult population represents a 71.6% increase in incidence compared with the mean incidence of 6.7 per 100,000 adult population from previous data for 2008-2016. There has also been a significant increase in number of cases diagnosed on separate sampling from the right and left colon (85% in 2019-2020 compared with 30% in 2008-2016; p < 0.001). Overall compliance with coeliac serology testing has improved, with 89% tested in 2017-2018 compared with 75% in 2008-2016.

CONCLUSION

Clinicopathological communication has contributed to an increased incidence of microscopic colitis in Northern Ireland through better endoscopic diagnostic sampling and pathology coding practices. Coeliac serology testing has also improved, although continued clinical awareness is required of the need for coeliac serology testing in all patients diagnosed with microscopic colitis.

Chologene Diarrhö, Stiefkind der chronischen Diarrhö – Prävalenz, Diagnostik und Therapie

Die chologene Diarrhö ist eine der häufigsten nicht diagnostizierten Ursachen der chronischen Diarrhö, der zahlreiche verschiedene Pathophysiologien zugrunde liegen können. Auch nach Ausschlussdiagnostik der häufigeren Ursachen verbleiben bis zu 5% der Bevölkerung von einer ungeklärten chronischen Diarrhö betroffen. In diesem Kollektiv findet sich in bis zu 50% als Ursache eine chologene Diarrhö.

Celiac Patient With New Episodes of Diarrhea: A Case Report

Celiac disease is a relatively common autoimmune disease that affects the gut's ability to process gluten. It is frequently associated with other autoimmune diseases. In this article, the authors present a clinical case of a 65-year-old female patient with a history of celiac disease and autoimmune hypothyroidism. This patient was admitted to the emergency room with generalized edema and chronic diarrhea with mucus as well as reports of unusual weight loss. A requested fecal analysis tested positive for fecal calprotectin. An endoscopic study further displayed flattening of the intestinal villi. A subsequent biopsy expressed overlapping evidence for both celiac disease and lymphocytic colitis. This case illustrates how a diagnosis of microscopic colitis should be explored when celiac patients with a history of a stable gluten-free diet display a sudden onset of chronic diarrhea. As the symptoms associated with this disease can often become debilitating, an early diagnosis and treatment are crucial.

Effectiveness of diet, psychological, and exercise therapies for the management of bile acid diarrhoea in adults: A systematic review

BACKGROUND

Bile acid diarrhoea (BAD) causes chronic diarrhoea and is primarily treated pharmacologically. This systematic review aimed to evaluate the effectiveness of non-pharmacological therapies for evidence-based management of BAD in adults.

METHODS

A systematic review of the medical literature was performed from 1975 to 13 July 2021 to identify studies on diet, psychological, and exercise therapies that met diagnostic criteria for BAD in adults with diarrhoea. Effectiveness was judged by responder or improvement in diarrhoea at study endpoint according to each study's definition of diarrhoea. Therapeutic effect on abdominal pain and flatulence was also measured. Risk of bias was assessed using the Risk Of Bias In Non-Randomised Studies of Interventions tool. A narrative review was conducted using 'Synthesis Without Meta-analysis' guidance. Certainty of the evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation.

RESULTS

Eight prospective cohort studies were identified on diet therapies from 2 weeks to over 2 years involving 192 patients. No psychological or exercise therapies were found. Carbohydrate modification (one study, n = 2) in primary BAD, and dietary fat intake reductions (five studies, n = 181) and an exclusive elemental diet therapy (two studies, n = 9) in secondary BAD, showed beneficial directions of effect on diarrhoea, abdominal pain, and flatulence. Risks of bias for each study and across studies for each therapy type were serious. Certainty of the evidence was very low for all outcomes.

CONCLUSIONS

No conclusions could be drawn on the effectiveness of diet, psychological, or exercise therapies on diarrhoea, abdominal pain, and flatulence for the management of BAD in adults. High-quality randomised controlled trials are needed.

Is mastocytic colitis a specific clinical-pathological entity?

The number of intestinal mast cells (MC) is increased in several types of colitis, but the mucosa of patients with chronic non-bloody diarrhea has not been studied. The current study sought to determine the relationship between MC counts and degranulation and the severity of symptoms in patients with chronic loose stools. Following a negative laboratory workup for the most common causes of chronic diarrhea, patients with chronic non-bloody loose stools were included in the study. Patients with macroscopic evidence of inflammation or organic disease were excluded after endoscopy with biopsies. Biopsies from the 179 patients in the study were stained with hematoxylin and eosin and anti-CD117 c-kit antibodies. Immunohistochemistry was used to assess the degree of MC degranulation. Out of the 179 patients, 128 had normal histologic findings suggestive of irritable bowel syndrome and were used as controls. Twenty-four presented with abnormally high MC counts (≥40 MC x HPF), 23 with ≥20 intraepithelial lymphocytes x HPF suggesting lymphocytic colitis, and 4 had both (≥40 MC and ≥20 intraepithelial lymphocytes x HPF). In the patients with high MC counts, figures were significantly higher in the right colon versus the left colon (p=0.016), but degranulation did not differ in the right versus the left colon (p=0.125). No age or sex-related difference was observed (p=0.527 and p=0.859 respectively). The prevalence of abdominal pain and bloating did not differ in the three groups (p=0.959 and p=0.140, respectively). Patients with lymphocytic colitis (p=0.008) and those with high MC counts (p=0.025) had significantly higher evacuation rates compared to controls. There was no difference between these two groups (p=0.831). Mast cell degranulation was not associated with the number of evacuations, abdominal pain, or bloating (p=0.51; p=0.41; p=0.42, respectively). The finding that a significantly higher number of evacuations was linked to increased MC in the colonic mucosa of a subset of patients with otherwise normal laboratory and endoscopic findings suggests that "mastocytic colitis" may be a new clinical-pathological entity responsible for chronic non-bloody diarrhea. Prospective studies with a larger number of patients, as well as endoscopic and histological follow-up, are needed to confirm this hypothesis.