Guidelines for the investigation of chronic diarrhoea, 2nd edition

Other Causes of Chronic Diarrhea in Children

Chronic diarrhea is still an important cause of morbidity and mortality in children. There are several causes of chronic diarrhea which may be due to intestinal, extra-intestinal or underlying systemic diseases. The etiology varies depending on the age of onset and may include both common and uncommon disorders. In this article some of the uncommon disorders such as immune deficiencies, intestinal lymphangiectasias, drug induced diarrhea, eosinophilic gastrointestinal disorders, endocrinopathies, neuroendocrine secretory tumors, malignancy and factitious diarrhea have been included. Though these disorders are uncommon it is essential that they are considered in select situations as detailed below and evaluated so that definitive therapy may be offered.

Impacts of pancreatic exocrine insufficiency on gut microbiota

Pancreatic exocrine insufficiency (PEI) can be induced by various kinds of diseases, including chronic pancreatitis, acute pancreatitis, and post-pancreatectomy. The main pathogenetic mechanism of PEI involves the decline of trypsin synthesis, disorder of pancreatic fluid flow, and imbalance of secretion feedback. Animal studies have shown that PEI could induce gut bacterial overgrowth and dysbiosis, with the abundance of Lactobacillus and Bifidobacterium increasing the most, which could be partially reversed by pancreatic enzyme replacement therapy. Clinical studies have also confirmed the association between PEI and the dysbiosis of gut microbiota. Pancreatic exocrine secretions and changes in duodenal pH as well as bile salt malabsorption brought about by PEI may affect and shape the abundance and composition of gut microbiota. In turn, the gut microbiota may impact the pancreatic exocrine acinus through potential bidirectional crosstalk. Going forward, more and higher-quality studies are needed that focus on the mechanism underlying the impact of PEI on the gut microbiota.

Small bowel diverticulosis: imaging appearances, complications, and pitfalls

Diverticula of the small bowel can be categorised as true, with Meckel's being the only example, or false. False small bowel diverticula (SBD) are acquired through herniation of the internal layers of the bowel wall through the muscularis propria. Peri-ampullary duodenal diverticula are a well-recognised example; however, the importance of more distal SBD in the jejunum and ileum is underappreciated, and they are under-reported on cross-sectional imaging. SBD are a known cause of anaemia, malabsorption, and diarrhoea, and there are myriad complications of SBD and Meckel's diverticula, which range in severity from inflammation and perforation to haemorrhage, tumour formation, and obstruction. Before the advent of computed tomography (CT), SBD were readily diagnosed on fluoroscopic oral contrast studies; however, radiologists are less comfortable with their cross-sectional imaging appearances. This imaging review combines our experience of multiple proven cases, with illustrative diagrams and radiological images of SBD to provide distinct imaging characteristics, allowing for confident diagnosis of SBD and their numerous complications. We discuss the importance of SBD as a cause of benign, non-surgical pneumoperitoneum. We additionally provide important pitfalls to be aware of such as SBD masquerading as other abnormalities.

European guideline on indications, performance and clinical impact of 13 C-breath tests in adult and pediatric patients: An EAGEN, ESNM, and ESPGHAN consensus, supported by EPC

Introduction

¹³C‐breath tests are valuable, noninvasive diagnostic tests that can be widely applied for the assessment of gastroenterological symptoms and diseases. Currently, the potential of these tests is compromised by a lack of standardization regarding performance and interpretation among expert centers.

Methods

This consensus‐based clinical practice guideline defines the clinical indications, performance, and interpretation of ¹³C‐breath tests in adult and pediatric patients. A balance between scientific evidence and clinical experience was achieved by a Delphi consensus that involved 43 experts from 18 European countries. Consensus on individual statements and recommendations was established if ≥ 80% of reviewers agreed and <10% disagreed.

Results

The guideline gives an overview over general methodology of ¹³C‐breath testing and provides recommendations for the use of ¹³C‐breath tests to diagnose Helicobacter pylori infection, measure gastric emptying time, and monitor pancreatic exocrine and liver function in adult and pediatric patients. Other potential applications of ¹³C‐breath testing are summarized briefly. The recommendations specifically detail when and how individual ¹³C‐breath tests should be performed including examples for well‐established test protocols, patient preparation, and reporting of test results.

Conclusion

This clinical practice guideline should improve pan‐European harmonization of diagnostic approaches to symptoms and disorders, which are very common in specialist and primary care gastroenterology practice, both in adult and pediatric patients. In addition, this guideline identifies areas of future clinical research involving the use of ¹³C‐breath tests.

The Role of Purported Mucoprotectants in Dealing with Irritable Bowel Syndrome, Functional Diarrhea, and Other Chronic Diarrheal Disorders in Adults

Chronic diarrhea is a frequent presenting symptom, both in primary care medicine and in specialized gastroenterology units. It is estimated that more than 5% of the global population suffers from chronic diarrhea. and that about 40% of these subjects are older than 60 years. The clinician is frequently faced with the need to decide which is the best therapeutic approach for these patients. While the origin of chronic diarrhea is diverse, impairment of intestinal barrier function, dysbiosis. and mucosal micro-inflammation are being increasingly recognized as underlying phenomena characterizing a variety of chronic diarrheal diseases. In addition to current pharmacological therapies, there is growing interest in alternative products such as mucoprotectants, which form a mucoadhesive film over the epithelium to reduce and protect against the development of altered intestinal permeability, dysbiosis, and mucosal micro-inflammation. This manuscript focuses on chronic diarrhea in adults, and we will review recent evidence on the ability of these natural compounds to improve symptoms associated with chronic diarrhea and to exert protective effects for the intestinal barrier.

Pancreatic exocrine insufficiency after pancreaticoduodenectomy: Current evidence and management

Pancreaticoduodenectomy (PD) is the commonest procedure performed for pancreatic cancer. Pancreatic exocrine insufficiency (PEI) may be caused or exacerbated by surgery and remains underdiagnosed and undertreated. The aim of this review was to ascertain the incidence of PEI, its consequences and management in the setting of PD for indications other than chronic pancreatitis. A literature search of databases (MEDLINE, EMBASE, Cochrane and Scopus) was carried out with the MeSH terms “pancreatic exocrine insufficiency” and “Pancreaticoduodenectomy”. Studies that analysed PEI and its complications in the setting of PD for malignant and benign disease were included. Studies reporting PEI in the setting of PD for chronic pancreatitis, conference abstracts and reviews were excluded. The incidence of PEI approached 100% following PD in some series. The pre-operative incidence varied depending on the characteristics of the patient cohort and it was higher (46%-93%) in series where pancreatic cancer was the predominant indication for surgery. Variability was also recorded with regards to the method used for the diagnosis and evaluation of pancreatic function and malabsorption. Pancreatic enzyme replacement therapy is the mainstay of the management. PEI is common and remains undertreated after PD. Future studies are required for the identification of a well-tolerated, reliable and reproducible diagnostic test in this setting.

Canadian Association of Gastroenterology Clinical Practice Guideline on the Management of Bile Acid Diarrhea

BACKGROUND & AIMS

Chronic diarrhea affects about 5% of the population overall. Altered bile acid metabolism is a common but frequently undiagnosed cause.

METHODS

We performed a systematic search of publication databases for studies of assessment and management of bile acid diarrhea (BAD). The certainty (quality) of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development and Evaluation approach. Patient population, intervention, comparator, and outcome questions were developed through an iterative process and were voted on by a group of specialists.

RESULTS

The certainty of evidence was generally rated as very low. Therefore, 16 of 17 recommendations are conditional. In patients with chronic diarrhea, consideration of risk factors (terminal ileal resection, cholecystectomy, or abdominal radiotherapy), but not additional symptoms, was recommended for identification of patients with possible BAD. The group suggested testing using ⁷⁵selenium homocholic acid taurine (where available) or 7α-hydroxy-4-cholesten-3-one, including patients with irritable bowel syndrome with diarrhea, functional diarrhea, and Crohn's disease without inflammation. Testing was suggested over empiric bile acid sequestrant therapy (BAST). Once remediable causes are managed, the group suggested cholestyramine as initial therapy, with alternate BAST when tolerability is an issue. The group suggested against BAST for patients with extensive ileal Crohn's disease or resection and suggested alternative antidiarrheal agents if BAST is not tolerated. Maintenance BAST should be given at the lowest effective dose, with a trial of intermittent, on-demand administration, concurrent medication review, and reinvestigation for patients whose symptoms persist despite BAST.

CONCLUSIONS

Based on a systematic review, BAD should be considered for patients with chronic diarrhea. For patients with positive results from tests for BAD, a trial of BAST, initially with cholestyramine, is suggested.

Canadian Association of Gastroenterology Clinical Practice Guideline on the Management of Bile Acid Diarrhea

Background and Aims

Chronic diarrhea affects about 5% of the population overall. Altered bile acid metabolism is a common but frequently undiagnosed cause.

Methods

We performed a systematic search of publication databases for studies of assessment and management of bile acid diarrhea (BAD). The certainty (quality) of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development and Evaluation approach. Patient population, intervention, comparator and outcome questions were developed through an iterative process and were voted on by a group of specialists.

Results

The certainty of evidence was generally rated as very low. Therefore, 16 of 17 recommendations are conditional. In patients with chronic diarrhea, consideration of risk factors (terminal ileal resection, cholecystectomy or abdominal radiotherapy), but not additional symptoms, was recommended for identification of patients with possible BAD. The group suggested testing using ⁷⁵selenium homocholic acid taurine (where available) or 7α-hydroxy-4-cholesten-3-one, including patients with irritable bowel syndrome with diarrhea, functional diarrhea and Crohn's disease without inflammation. Testing was suggested over empiric bile acid sequestrant therapy (BAST). Once remediable causes are managed, the group suggested cholestyramine as initial therapy, with alternate BAST when tolerability is an issue. The group suggested against BAST for patients with extensive ileal Crohn's disease or resection and suggested alternative antidiarrheal agents if BAST is not tolerated. Maintenance BAST should be given at the lowest effective dose, with a trial of intermittent, on-demand administration, concurrent medication review and reinvestigation for patients whose symptoms persist despite BAST.

Conclusions

Based on a systematic review, BAD should be considered for patients with chronic diarrhea. For patients with positive results from tests for BAD, a trial of BAST, initially with cholestyramine, is suggested.

Constipation, diarrhea, and prophylactic laxative bowel regimens in the critically ill: A systematic review and meta-analysis

INTRODUCTION

Prophylactic laxative bowel regimens may prevent constipation in enterally-fed critically ill patients. However, their use may also increase diarrhea. We performed a systematic review to: 1. Explore the epidemiology of constipation and/or diarrhea in critically ill patients; and 2. Appraise trials evaluating prophylactic laxative bowel regimens.

METHODS

We searched MEDLINE, Embase, and CINAHL for publications that reported constipation or diarrhea in critically ill adult patients and/or prophylactic laxative bowel regimens.

RESULTS

The proportion of critically ill patients experiencing constipation was reported between 20% and 83% and the proportion experiencing diarrhea was reported between 3.3% and 78%. Six studies of prophylactic laxative bowel regimens were identified but only 3 randomised controlled trials were identified, and these were subjected to meta-analysis. Compared with placebo, a prophylactic laxative bowel regimen increased the risk of diarrhea (RR 1.58, 95% CI 1.22 to 2.04) but did not reduce the risk of constipation (RR 0.39, 95% CI 0.14 to 1.05), and did not affect the duration of mechanical ventilation, duration of ICU admission, or mortality.

CONCLUSIONS

Constipation and diarrhea occur frequently in the critically ill but data evaluating prophylactic laxative bowel regimens in such patients are sparse and do not support their use.

Evaluation of the Antispasmodic and Antisecretory Activities of the 80% Methanol Extracts of Verbena officinalis L: Evidence From In Vivo Antidiarrheal Study

Verbena officinalis L. has a folkloric repute for the management of digestive disorders, including diarrhea. However, the safety and efficacy of the plant material has not been scientifically validated yet. This study was, therefore, aimed to evaluate the overall antidiarrheal activity of the 80% methanol extracts of V officinalis in mice. The antidiarrheal activity of the 80% methanol extracts of the roots (R-80ME) and the leaves (L-80ME) of V officinalis was tested in castor oil-induced diarrhea in mice. R-80ME was further evaluated using charcoal meal and entero-pooling. In each test, group I and group II (controls) received 10 mL/kg distilled water and standard drug (5 mg/kg loperamide), respectively, whereas groups III, IV, and V (test groups) received 100, 200, and 400 mg/kg of the 80ME, respectively. The R-80ME at 200 mg/kg (P < .01) and 400 mg/kg (P < .001) significantly delayed the onset of diarrhea compared with negative control. Both R-80ME and L-80ME at 200 and 400 mg/kg significantly decreased the frequency of wet fecal outputs (P < .01). Generally, 70.24% inhibition of the number of wet fecal output was recorded at R-80ME 400 mg/kg. Results from the charcoal meal test revealed that the R-80ME at 200 (P < .01) and 400 mg/kg (P < .001) produced a significant antimotility effect. In entero-pooling test, the R-80ME, at 200 and 400 mg/kg doses (P < .01), showed a significant decline in both the volume and weight of intestinal contents. The maximum in vivo antidiarrheal index was determined to be 95.25 at dose of 400 mg/kg R-80ME. This study demonstrated that the 80ME, mainly the root extract, produced promising antidiarrheal activity and hence provides a scientific support for acclaimed traditional use of the plant material for treatment of diarrheal diseases.

Pathophysiology and Treatment of Gastrointestinal Motility Disorders in the Acutely Ill

Gastrointestinal dysmotility causes delayed gastric emptying, enteral feed intolerance, and functional obstruction of the small and large intestine, the latter functional obstructions being frequently termed ileus and Ogilvie syndrome, respectively. In addition to meticulous supportive care, drug therapy may be appropriate in certain situations. There is, however, considerable variation among individuals regarding what gastric residual volume identifies gastric dysmotility and would encourage use of a promotility drug. While the administration of either metoclopramide or erythromycin is supported by evidence it appears that, dual-drug therapy (erythromycin and metoclopramide) reduces the rate of treatment failure. There is a lack of evidence to guide drug therapy of ileus, but neither erythromycin nor metoclopramide appear to have a role. Several drugs, including ghrelin agonists, highly selective 5-hydroxytryptamine receptor agonists, and opiate antagonists are being studied in clinical trials. Neostigmine, when infused at a relatively slow rate in patients receiving continuous hemodynamic monitoring, may alleviate the need for endoscopic decompression in some patients.

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

Chronic diarrhoea is a common problem, hence clear guidance on investigations is required. This is an updated guideline from 2003 for the investigations of chronic diarrhoea commissioned by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG). This document has undergone significant revision in content through input by 13 members of the Guideline Development Group (GDG) representing various institutions. The GRADE system was used to appraise the quality of evidence and grading of recommendations.

Lower gastrointestinal symptoms are associated with worse glycemic control and quality of life in type 1 diabetes mellitus

OBJECTIVES

Lower gastrointestinal symptoms are not well characterized in people with type 1 diabetes, and the effects on quality of life and glycemic control are unknown. This study aimed to determine the prevalence of lower gastrointestinal symptoms and the effects on glycemic control and quality of life, and to investigate for underlying causes.

RESEARCH DESIGN AND METHODS

This is a prospective, cohort study in secondary care. Patients with type 1 diabetes completed a gastrointestinal symptom questionnaire and the Short Form 36 V.2 quality of life questionnaire and had their hemoglobin A1c measured. Patients with diarrhea were offered reassessment and investigation as per the national guidelines. Controls without diabetes were used to compare symptom prevalence and quality of life scores.

RESULTS

706 with type 1 diabetes (mean age 41.9 years) and 604 controls (mean age 41.9 years) were enrolled. Gastrointestinal symptoms were significantly more frequent in type 1 diabetes compared with controls, in particular constipation (OR 2.4), diarrhea (OR 2.5), alternating bowel habit (OR 2.1), abdominal pain (OR 1.4), floating stools (OR 2.7), bloating (OR 1.4) and flatulence (OR 1.3) (all p<0.05). Previous pancreatitis was more frequent in type 1 diabetes (OR 4.6), but other gastrointestinal conditions were not. Gastrointestinal symptoms were associated with poorer glycemic control (p<0.01) and worse quality of life particularly in those with diarrhea. Investigation of those with diarrhea, including those with alternating bowel habit, (n=105), identified a cause in 72.3% with subsequent change in management.

CONCLUSIONS

Gastrointestinal symptoms are twice as common in type 1 diabetes and associated with poorer quality of life and glycemic control. Investigation of diarrhea in people with type 1 diabetes leads to a high yield of treatable conditions and a change in management in about three-quarters.

HIV and diarrhoea: what is new? Curr Opin Infect Dis. 2016;29:486-494. [PMID: 27472290 DOI: 10.1097/qco.0000000000000305]

PURPOSE OF REVIEW

The review examines the changing causes and the investigation of infectious and noninfectious diarrhoea in individuals with HIV.

RECENT FINDINGS

Despite the excellent prognosis conferred by combination antiretroviral therapy, diarrhoea is still common in HIV-positive individuals and is associated with reduced quality of life and survival. There is increasing interest in the importance of Th17 and Th22 T cells in the maintenance of mucosal immunity within the gut, and in the role of the gut microbiome in gut homeostasis. Bacterial causes of HIV-associated diarrhoea continue to be important in resource-poor settings. In other settings, sexually transmitted enteric infections such as lymphogranuloma venereum and shigellosis are increasingly reported in men who have sex with men. HIV increases the risk of such infections and the presence of antimicrobial resistance. Parasitic causes of diarrhoea are more common in individuals with uncontrolled HIV and low CD4 counts. Noninfectious causes of diarrhoea include all classes of antiretroviral therapy, which is under-recognised as a cause of poor treatment adherence. Pancreatic dysfunction is remediable and the diagnostic workup of HIV-related diarrhoea should include faecal elastase measurements. New antimotility agents such as crofelemer may be useful in managing secretory diarrhoea symptoms.

SUMMARY

Clinicians looking after patients with HIV should ask about diarrhoeal symptoms, which are under-reported and may have a remediable infectious or noninfectious cause.

A positive SeHCAT test results in fewer subsequent investigations in patients with chronic diarrhoea

Chronic diarrhoea is a common condition, resulting from a number of different disorders. Bile acid diarrhoea, occurring in about a third of these patients, is often undiagnosed. We hypothesised that a positive diagnosis of bile acid diarrhoea would reduce the need for subsequent investigations for alternative diagnoses.

METHODS

Patients previously recruited to a study of chronic diarrhoea who had selenium homocholic acid taurine (SeHCAT) testing and subsequent follow-up at our institution were identified. In a retrospective analysis, the numbers of defined investigations undertaken from the first 3 months after SeHCAT in the following 5 years were compared.

RESULTS

90 patients were identified with primary bile acid diarrhoea (SeHCAT retention <15%, n=36) or idiopathic diarrhoea (SeHCAT retention >15%, n=54). Follow-up had been performed on 29 and 39 subjects, respectively, with no differences in previous investigations or the last contact date. In the follow-up period, the proportions of these patients who had undergone endoscopic procedures (gastroscopy, colonoscopy and sigmoidoscopy) were the same. However, there was a higher proportion of patients in the SeHCAT-negative group who had other investigations, including imaging, physiological tests and blood tests (p=0.037). The use of cross-sectional imaging was significantly higher in this group (p=0.015) with greater proportions having CT (0.44 vs 0.10) and MRI (0.26 vs 0.07). Ultrasound use and the number of blood tests were higher in the SeHCAT-negative group whereas the SeHCAT-positive group attended more clinic appointments (p=0.013).

CONCLUSION

A positive diagnosis of bile acid diarrhoea, made by a SeHCAT test, resulted in reduced use of diagnostic investigations over the subsequent 5 years.

Evaluation of the antidiarrheal activity of the leaf extracts of Myrtus communis Linn (Myrtaceae) in mice model

Background

Myrtus communis L. has a folkloric repute for the management of diarrhea and dysentery in different parts of the world. However, the safety and efficacy of the leaf extract have not been scientifically validated in animal model. This study was, therefore, aimed to investigate the antidiarrheal effect of 80% methanol extract (80ME) and solvent fractions of the leaves of Myrtus communis L. in mice.

Methods

The antidiarrheal activity of the 80ME and solvent fractions was evaluated against castor oil induced diarrheal model, charcoal meal and enteropooling tests. For the 80%ME, the test groups received 100, 200 and 400 mg/kg of the extract. In case of fractions, the test groups received various doses of fractions (200, 300, 400 mg/kg and an additional dose of 800 mg/kg for the aqueous fraction (AF)), where as negative controls received the vehicle (10 ml/kg) and positive controls received loperamide (3 mg/kg).

Results

The 80ME at 200 mg/kg (p < 0.05) & 400 mg/kg (p < 0.01) as well as the chloroform fraction (CF) and methanol fraction (MF) at 400 mg/kg (p < 0.05) significantly delayed the onset of diarrhea. Besides, the 80ME (at all tested doses) and both of these fractions (at 300 & 400 mg/kg) significantly decreased the frequency and weight of fecal outputs. Results from the charcoal meal test revealed that the 80ME, at all doses, (p < 0.001) as well as the CF and MF at 300 mg/kg (p < 0.05) & 400 mg/kg (p < 0.001) produced a significant anti-motility effect. Similarly, in the entero-pooling test, the 80ME (at all tested doses) (p < 0.01) as well as the CF and MF (at 300 & 400 mg/kg, p < 0.05) produced a significant decline in the weight and volume of intestinal contents, whereas the AF revealed significant effect (p < 0.05) at dose of 800 mg/kg only.

Conclusion

The study demonstrated that the 80ME and solvent fractions contain bioactive constituents that have antidiarrheal activity. Therefore, this study provides a scientific support for the acclaimed traditional use of Myrtus communis L for the treatment of diarrheal diseases.

Expert opinions and scientific evidence for colonoscopy key performance indicators

Colonoscopy is a widely performed procedure with procedural volumes increasing annually throughout the world. Many procedures are now performed as part of colorectal cancer screening programmes. Colonoscopy should be of high quality and measures of this quality should be evidence based. New UK key performance indicators and quality assurance standards have been developed by a working group with consensus agreement on each standard reached. This paper reviews the scientific basis for each of the quality measures published in the UK standards.

75SeHCAT scan in bile acid malabsorption in chronic diarrhoea

Chronic diarrhoea is a common entity in daily clinical practice and it leads to a loss in these patients quality of life. It may be the main symptom of multiple ethiologies including bile acid malabsorption (BAM) which has a comparable prevalence to celiac disease. The BAM results from imbalances in the homeostasis of bile acids in the enterohepatic circulation. It can be a consequence of ileal disease or ileal dysfunction (BAM type i), it can be considered idiopathic or primary (BAM type ii) or associated with other gastrointestinal entities (BAM type iii). Among the different diagnostic methods available, ⁷⁵SeHCAT study is the primary current method due to its sensitivity, specificity, safety and low cost. The main disadvantage is that it's not available in all countries, so other diagnostic methods have appeared, such as serum measurement of FGF19 and C4, however they are significantly more complex and costly. The first-line treatment of bile acid diarrhoea is bile acid sequestrant, such as cholestyramine, which can be difficult to administer due to its poor tolerability and gastrointestinal side effects. These are less prominent with newer agents such as colesevelam. In summary, the BAM is a common entity underdiagnosed and undertreated, so it is essential to establish a diagnosis algorithm of chronic diarrhoea in which the ⁷⁵SeHCAT study would be first or second line in the differential diagnosis of these patients.

Lanreotide Autogel in the Treatment of Idiopathic Refractory Diarrhea: Results of an Exploratory, Controlled, Before and After, Open-label, Multicenter, Prospective Clinical Trial

PURPOSE

Chronic idiopathic diarrhea is the passage of loose stools >3 times daily, or a stool weight >200 g/d, persisting for >4 weeks without clear clinical cause. Patients refractory to standard anti-diarrhetics have limited treatment options. Somatostatin analogues have the ability to reduce gastrointestinal secretions and motility. This study evaluated the efficacy and safety of lanreotide Autogel(*) 120 mg in chronic idiopathic diarrhea.

METHODS

Other anti-diarrhetics were not allowed during the study and were stopped at screening. Patients received lanreotide Autogel 120 mg at baseline and day 28. Stool frequency and consistency (Bristol Stool Scale) were recorded; quality of life (QoL) was assessed using the 36-item Short Form Health Survey and irritable bowel syndrome QoL questionnaires; adverse events were monitored. The primary outcome was the proportion of patients with a reduction of ≥50% or normalization to a mean of ≤3 stools/d at day 28.

FINDINGS

Thirty-three patients with >3 stools/d at baseline were included; mean (SD) age was 55.2 (16.4) years. Fourteen patients (42.4%) had a response to lanreotide Autogel at day 28 and 17 (51.5%) at day 56. Mean (SD) number of stools decreased significantly from 5.7 (2.2) at baseline to 3.7 (2.2) at day 56 overall (n = 32; P < 0.001). Significant and clinically meaningful improvements in disease-specific QoL were found in the overall populations. No new safety signals emerged.

IMPLICATIONS

Lanreotide Autogel 120 mg decreased symptoms in these patients with chronic idiopathic refractory diarrhea, and meaningfully improved QoL. These finding have to be confirmed in further clinical trials. ClinicalTrials.gov

IDENTIFICATION

NCT00891371; Eudract CT 2009-009356-20.

PCSK1 Mutations and Human Endocrinopathies: From Obesity to Gastrointestinal Disorders

Prohormone convertase 1/3, encoded by the PCSK1 gene, is a serine endoprotease that is involved in the processing of a variety of proneuropeptides and prohormones. Humans who are homozygous or compound heterozygous for loss-of-function mutations in PCSK1 exhibit a variable and pleiotropic syndrome consisting of some or all of the following: obesity, malabsorptive diarrhea, hypogonadotropic hypogonadism, altered thyroid and adrenal function, and impaired regulation of plasma glucose levels in association with elevated circulating proinsulin-to-insulin ratio. Recently, more common variants in the PCSK1 gene have been found to be associated with alterations in body mass index, increased circulating proinsulin levels, and defects in glucose homeostasis. This review provides an overview of the endocrinopathies and other disorders observed in prohormone convertase 1/3-deficient patients, discusses the possible biochemical basis for these manifestations of the disease, and proposes a model whereby certain missense mutations in PCSK1 may result in proteins with a dominant negative action.

Elevated fecal levels of eosinophil granule proteins predict collagenous colitis in patients referred to colonoscopy due to chronic non-bloody diarrhea

OBJECTIVE

Colonoscopy with biopsy sampling is often performed to detect collagenous colitis (CC) and lymphocytic colitis (LC) in patients with chronic non-bloody diarrhea. However, the diagnostic yield is low and incurs high costs. Fecal calprotectin (FC) and myeloperoxidase (MPO) indicate intestinal inflammation in ulcerative colitis (UC) and Crohn's disease (CD). In CC, elevated fecal levels of eosinophil protein X (EPX) and eosinophil cationic protein (ECP) have been reported. We aimed to evaluate if F-EPX, F-ECP, FC, and F-MPO could predict the diagnostic outcome in patients with chronic non-bloody diarrhea referred to colonoscopy. We also evaluated serum (S) EPX and ECP in this regard.

METHODS

Of 67 included patients, 63 (94%) underwent colonoscopy with biopsy sampling. Fecal EPX, F-ECP, FC, F-MPO, S-EPX, and S-ECP were analyzed.

RESULTS

Diagnostic outcome: normal: n = 46 (73%), CC: n = 9 (14%), LC: n = 4 (6%), UC: n = 2 (3%), CD: n = 2 (3%). Higher levels of F-EPX and F-ECP were found in CC compared to a normal diagnostic outcome (p = 0.01). No change was noted in any of the fecal markers in LC. When all of the fecal markers were normal the probability of a normal diagnostic outcome was 92%. We found no differences in S-EPX and S-ECP between the groups.

CONCLUSION

Elevated F-EPX and F-ECP could predict CC. None of the fecal markers predicted LC. Serum-EPX and S-ECP are not useful for the diagnosis of CC, LC, UC, or CD. With normal levels in all of the analyzed fecal markers, there is a low probability of a pathologic diagnostic outcome.

Multicentre prospective survey of SeHCAT provision and practice in the UK

Objective

A clinical diagnosis of bile acid malabsorption (BAM) can be confirmed using SeHCAT (tauroselcholic (⁷⁵selenium) acid), a radiolabelled synthetic bile acid. However, while BAM can be the cause of chronic diarrhoea, it is often overlooked as a potential diagnosis. Therefore, we investigated the use of SeHCAT for diagnosis of BAM in UK hospitals.

Design

A multicentre survey was conducted capturing centre and patient-level information detailing patient care-pathways, clinical history, SeHCAT results, treatment with bile acid sequestrants (BAS), and follow-up in clinics. Eligible data from 38 centres and 1036 patients were entered into a validated management system.

Results

SeHCAT protocol varied between centres, with no standardised patient positioning, and differing referral systems. Surveyed patients had a mean age of 50 years and predominantly women (65%). The mean SeHCAT retention score for all patients was 19% (95% CI 17.8% to 20.3%). However, this differed with suspected BAM type: type 1: 9% (95% CI 6.3% to 11.4%), type 2: 21% (95% CI 19.2% to 23.0%) and type 3: 22% (95% CI 19.6% to 24.2%). Centre-defined ‘abnormal’ and ‘borderline’ results represented over 50% of the survey population. BAS treatment was prescribed to only 73% of patients with abnormal results.

Conclusions

The study identified a lack of consistent cut-off/threshold values, with differing centre criteria for defining an ‘abnormal’ SeHCAT result. BAS prescription was not related in a simple way to the SeHCAT result, nor to the centre-defined result, highlighting a lack of clear patient care-pathways. There is a clear need for a future diagnostic accuracy study and a better understanding of optimal management pathways.

Review article: bile acid diarrhoea - pathogenesis, diagnosis and management

BACKGROUND

Bile acid diarrhoea results from imbalances in the homoeostasis of bile acids in the enterohepatic circulation. It can be a consequence of ileal disease/dysfunction, associated with other GI pathology or can be idiopathic.

AIMS

To summarise the different types of bile acid diarrhoea and discuss the currently available diagnostic methods and treatments.

RESULTS

Bile acid diarrhoea is found in up to 40% of patients diagnosed as having functional diarrhoea/IBS-D, and in up to 80% of patients who have undergone ileal resection. It is likely under-diagnosed and under-treated. In idiopathic disease, errors in regulation feedback of fibroblast growth factor 19 contribute to the development of the condition. Clinical therapeutic trials for bile acid diarrhoea have been used to diagnose it, but the ⁷⁵ SeHCAT test is the primary current method. It is sensitive, specific and widely available, though not in the USA. Other diagnostic methods (such as serum measurement of the bile acid intermediate 7α-hydroxy-4-cholesten-3-one, or C4) have less widespread availability and documentation, and some (such as faecal measurement of bile acids) are significantly more complex and costly. First-line treatment of bile acid diarrhoea is with the bile acid sequestrant cholestyramine, which can be difficult to administer and dose due to gastrointestinal side effects. These side effects are less prominent in newer agents such as colesevelam, which may provide higher efficacy, tolerability and compliance.

CONCLUSION

Bile acid diarrhoea is common, and likely under-diagnosed. Bile acid diarrhoea should be considered relatively early in the differential diagnosis of chronic diarrhoea.

Prevalence, symptom patterns and management of episodic diarrhoea in the community: a population-based survey in 11 countries

BACKGROUND

The extent of episodic diarrhoea in the community is relatively unknown.

AIM

To ascertain the prevalence, symptoms and management behaviours associated with self-reported diarrhoea across 11 countries.

METHODS

Community screening surveys were conducted using quota sampling of respondents to identify a nationally representative sample of individuals suffering from 'episodic' diarrhoea (occurring once a month or more often). Second-phase in-depth surveys provided data on epidemiology, symptoms, attributed causes and management of episodic diarrhoea.

RESULTS

A total of 11 508 phase 1 and 6613 phase 2 surveys were completed. The prevalence of self-reported episodic diarrhoea ranged from 16% to 23% across the 11 countries. The majority of episodic diarrhoea sufferers were female (57%) and were not diagnosed with pre-existing irritable bowel syndrome (IBS); IBS diagnosis ranged from 9% in Mexico to 44% in Italy. Diarrhoea was frequently attributed to anxiety/stress, food-related causes, gastrointestinal 'sensitivity' and menstruation. Accompanying symptoms included 'stomach pain/cramping' (35-62%), 'stomach grumbling' (29-68%) and 'wind' (18-74%). The proportion of episodic sufferers who reported treating their symptoms with remedies or medications ranged between 46% in Belgium and Canada and 90% in Mexico.

CONCLUSIONS

A substantial proportion of the population in middle- to high-income countries report episodic diarrhoea in the absence of a pre-existing diagnosis. These symptoms are likely to be associated with substantial social and economic costs, and have implications on how best to configure and guide self-led, pharmacist-led and primary care management.

Guidance on the management of diarrhoea during cancer chemotherapy. Lancet Oncol. 2014;15:e447-e460. [PMID: 25186048 DOI: 10.1016/s1470-2045(14)70006-3]

Diarrhoea induced by chemotherapy in cancer patients is common, causes notable morbidity and mortality, and is managed inconsistently. Previous management guidelines were based on poor evidence and neglect physiological causes of chemotherapy-induced diarrhoea. In the absence of level 1 evidence from randomised controlled trials, we developed practical guidance for clinicians based on a literature review by a multidisciplinary team of clinical oncologists, dietitians, gastroenterologists, medical oncologists, nurses, pharmacist, and a surgeon. Education of patients and their carers about the risks associated with, and management of, chemotherapy-induced diarrhoea is the foundation for optimum treatment of toxic effects. Adequate--and, if necessary, repeated--assessment, appropriate use of loperamide, and knowledge of fluid resuscitation requirements of affected patients is the second crucial step. Use of octreotide and seeking specialist advice early for patients who do not respond to treatment will reduce morbidity and mortality. In view of the burden of chemotherapy-induced diarrhoea, appropriate multidisciplinary research to assess meaningful endpoints is urgently required.

The effect of bariatric surgery on intestinal absorption and transit time. Obes Surg. 2014;24:796-805. [PMID: 24374942 DOI: 10.1007/s11695-013-1166-x]

BACKGROUND

Bariatric surgical procedures are classified by their presumed mechanisms of action: restrictive, malabsorptive or a combination of both. However, this dogma is questionable and remains unproven. We investigated post-operative changes in nutrient absorption and transit time following bariatric surgery.

METHODS

Participants were recruited into four groups: obese controls (body mass index (BMI) >30 kg/m2, n = 7), adjustable gastric banding (n = 6), Roux-en-Y gastric bypass (RYGB, n = 7) and biliopancreatic diversion with duodenal switch (DS, n = 5). Participants underwent sulphasalazine/sulphapyridine tests (oro-caecal transit time); fasting plasma citrulline (functional enterocyte mass); 3 days faecal collection for faecal elastase 1 (FE-1); calprotectin (FCp); faecal fatty acids (pancreatic exocrine function, gut inflammation and fat excretion, respectively); and 5 h D-xylose, L-rhamnose and lactulose test (intestinal absorption and permeability).

RESULTS

Age and gender were not different but BMI differed between groups (p = 0.001). No difference in oro-caecal transit time (p = 0.935) or functional enterocyte mass (p = 0.819) was detected. FCp was elevated post-RYGB vs. obese (p = 0.016) and FE-1 was reduced post-RYGB vs. obese (p = 0.002). Faecal fat concentrations were increased post-DS vs. obese (p = 0.038) and RYGB (p = 0.024) and were also higher post-RYGB vs. obese (p = 0.033). Urinary excretion of D-xylose and L-rhamnose was not different between the groups; however, lactulose/rhamnose ratio was elevated post-DS vs. other groups (all p < 0.02), suggesting increased intestinal permeability.

CONCLUSIONS

Following RYGB, there are surprisingly few abnormalities or indications of severe malabsorption of fats or sugars. Small bowel adaptation after bariatric surgery may be key to understanding the mechanisms responsible for the beneficial metabolic effects of these operations.

New insights and challenges in microscopic colitis

Microscopic colitis (MC) is described as an inflammatory bowel disease characterized by chronic, bloodless diarrhea with normal or close to normal endoscopic findings. Histopathological examination reveals two subtypes: collagenous colitis (CC) and lymphocytic colitis (LC), which are indistinguishable clinically. The disease debuts typically in middle-aged patients, but can occur at all ages, including children. A female predominance is found in both CC and LC, but is not confirmed by others in LC. The etiology is unclear, but the disease has been assumed to be of autoimmune origin. However, several etiologies may render a microscopic inflammation in the mucosa; this is a common, universal reaction to a variety of irritants in contact with the intestinal lumen. Furthermore, some patients with a microscopic inflammation in their colonic mucosa have no symptoms, or are suffering from constipation or abdominal pain, rather than diarrhea. Recently, a discussion was initiated calling into question the overdiagnosing of symptoms and pointing out the danger of exacerbating people's perception of their ailments, of weakening their eligibility in health insurance, of overprescription of drugs, and thus the increasing cost to the society of health care. In the light of this discussion, this review will highlight histopathological and clinical features of MC, and discuss the diagnosis and management of this disease. Perhaps, the intestinal mucosa has no other mode by which to react than an inflammatory response, irrespective of the presence or absence of autoimmunity. Thus, to better identify and classify subgroups of MC, and to clarify and correctly handle the inflammatory changes, this field of research stands to benefit from a review of the results and experience gained to date.

Clinical potential of naloxegol in the management of opioid-induced bowel dysfunction

Opioid-induced bowel dysfunction (OIBD) is a burdensome condition which limits the therapeutic benefit of analgesia. It affects the entire gastrointestinal tract, predominantly by activating opioid receptors in the enteric nervous system, resulting in a wide range of symptoms, such as reflux, bloating, abdominal cramping, hard, dry stools, and incomplete evacuation. The majority of studies evaluating OIBD focus on constipation experienced in approximately 60% of patients. Nevertheless, other presentations of OIBD seem to be equally frequent. Furthermore, laxative treatment is often insufficient, which in many patients results in decreased quality of life and discontinuation of opioid treatment. Novel mechanism-based pharmacological approaches targeting the gastrointestinal opioid receptors have been marketed recently and even more are in the pipeline. One strategy is prolonged release formulation of the opioid antagonist naloxone (which has limited systemic absorption) and oxycodone in a combined tablet. Another approach is peripherally acting, μ-opioid receptor antagonists (PAMORAs) that selectively target μ-opioid receptors in the gastrointestinal tract. However, in Europe the only PAMORA approved for OIBD is the subcutaneously administered methylnaltrexone. Alvimopan is an oral PAMORA, but only approved in the US for postoperative ileus in hospitalized patients. Finally, naloxegol is a novel, oral PAMORA expected to be approved soon. In this review, the prevalence and pathophysiology of OIBD is presented. As PAMORAs seem to be a promising approach, their potential effect is reviewed with special focus on naloxegol's pharmacological properties, data on safety, efficacy, and patient-focused perspectives. In conclusion, as naloxegol is administered orally once daily, has proven efficacious compared to placebo, has an acceptable safety profile, and can be used as add-on to existing pain treatment, it is a welcoming addition to the targeted treatment possibilities for OIBD.

Bile acid diarrhoea and FGF19: new views on diagnosis, pathogenesis and therapy

Chronic diarrhoea induced by bile acids is common and the underlying mechanisms are linked to homeostatic regulation of hepatic bile acid synthesis by fibroblast growth factor 19 (FGF19). Increasing evidence, including that from several large case series using SeHCAT (selenium homocholic acid taurine) tests for diagnosis, indicates that bile acid diarrhoea (BAD) accounts for a sizeable proportion of patients who would otherwise be diagnosed with IBS. Studies of other approaches for diagnosis of BAD have shown increased bile acid synthesis, increased faecal levels of primary bile acids, dysbiosis and different urinary volatile organic compounds when compared with healthy controls or with other diseases. The role of the ileal hormone FGF19 in BAD has been strengthened: a prospective clinical study has confirmed low FGF19 levels in BAD, and so a test to measure these levels could be developed for diagnosis. In animal models, FGF19 depletion by antibodies produces severe diarrhoea. Bile acids affect colonic function through farnesoid X receptor (FXR) and TGR5 receptors. As well as these effects in the colon, FXR-dependent stimulation of ileal FGF19 production could be a logical mechanism to provide therapeutic benefit in BAD. Further studies of FGF19 in humans hold promise in providing novel treatments for this cause of chronic diarrhoea.

Bile acid malabsorption in chronic diarrhea: pathophysiology and treatment. Can J Gastroenterol. 2013;27:653-659. [PMID: 24199211 DOI: 10.1155/2013/485631]

BACKGROUND

Bile acid malabsorption (BAM) is a common but frequently under-recognized cause of chronic diarrhea, with an estimated prevalence of 4% to 5%.

METHODS

The published literature for the period 1965 to 2012 was examined for articles regarding the pathophysiology and treatment of BAM to provide an overview of the management of BAM in gastroenterology practice.

RESULTS

BAM is classified as type 1 (secondary to ileal dysfunction), type 2 (idiopathic) or type 3 (secondary to gastrointestinal disorders not associated with ileal dysfunction). The estimated prevalence of BAM is >90% in patients with resected Crohn disease (CD) and 11% to 52% of unresected CD patients (type 1); 33% in diarrhea-predominant irritable bowel syndrome (type 2); and is a frequent finding postcholecystectomy or postvagotomy (type 3). Investigations include BAM fecal bile acid assay, 23-seleno-25-homo-tauro-cholic acid (SeHCAT) testing and high-performance liquid chromatography of serum 7-α-OH-4-cholesten-3-one (C4), to determine the level of bile acid synthesis. A less time-consuming and expensive alternative in practice is an empirical trial of the bile acid sequestering agent cholestyramine. An estimated 70% to 96% of chronic diarrhea patients with BAM respond to short-course cholestyramine. Adverse effects include constipation, nausea, borborygmi, flatulence, bloating and abdominal pain. Other bile acid sequestering agents, such as colestipol and colesevelam, are currently being investigated for the treatment of BAM-associated diarrhea.

CONCLUSIONS

BAM is a common cause of chronic diarrhea presenting in gastroenterology practice. In accordance with current guidelines, an empirical trial of a bile acid sequestering agent is warranted as part of the clinical workup to rule out BAM.

Utility of testing patients, on presentation, for serologic features of celiac disease

BACKGROUND & AIMS

Celiac disease shares features of other disorders. It can be diagnosed conclusively only based on duodenal histology analysis, which is not practical for screening purposes. Serologic analysis might be used to identify candidates for biopsy analysis. We aimed to develop a simple diagnostic approach that all clinicians could follow to increase the percentage of patients accurately diagnosed with celiac disease at initial presentation.

METHODS

We performed a retrospective analysis of data from 752 patients (88 with celiac disease, none were IgA deficient) who attended a UK district general hospital from January 2007 through December 2008 and underwent biopsy analysis and serologic tests to measure endomyseal antibodies and IgA antibodies against tissue transglutaminase (tTG). Patients avoiding gluten in their diet were excluded. Patients were assigned to 1 of 4 groups: high-risk (based on presence of anemia, chronic diarrhea, unintentional weight loss, or dermatitis herpetiformis), low-risk (based on such factors as dyspepsia, abnormal liver function, ataxia, or chronic cough), nutrient deficiency (based on levels of iron, vitamins B12 and D, or folate), or screening (because they had type 1 diabetes or a family history of celiac disease). Patients with celiac disease were identified using the modified Marsh criteria (grades 1-3) for interpreting duodenal histology. We compared clinical category, serology profiles, and biopsy results between patients with and without celiac disease.

RESULTS

Celiac disease was diagnosed in 64 of 565 patients in the high-risk group (11%), 14 of 156 patients in the low-risk group (9%; P = .47 compared with high-risk group), 7 of 28 patients in the nutrient-deficiency group, and 3 of 3 patients in the screening group. Among 71 patients who tested positive for both antibodies (tTG and endomyseal antibodies), the positive predictive value for celiac disease was 97%; a negative test result for tTG had a negative predictive value of 98%. Among 708 patients with normal-looking biopsy samples, only 62 had celiac disease (9%). Among 44 patients with abnormal biopsy samples, 26 had celiac disease (59%).

CONCLUSIONS

Based on a retrospective analysis, patients with and without celiac disease cannot be distinguished based on clinical features. Patients who present with symptoms of celiac disease should be tested for tTG, to identify candidates for duodenal biopsy analysis.

Microscopic colitis and colorectal neoplastic lesion rate in chronic nonbloody diarrhea: a prospective, multicenter study

BACKGROUND

Lymphocytic and collagenous colitis are emerging as common findings in subjects undergoing colonoscopy for chronic non-bloody diarrhea (CNBD). Data concerning microscopic colitis (MC) are still limited and affected by controversial epidemiological evidences. Recent converging lines of evidence suggest that MC correlates a lower risk of colorectal neoplasia. Accordingly, we prospectively assessed MC prevalence in a multicenter cohort of subjects submitted to colonoscopy for CNBD, thereby defining whether MC influences the risk of colorectal neoplasia.

METHODS

Consecutive patients with CNBD of unknown origin underwent pan-colonoscopy with multiple biopsies. The prevalence of neoplastic patients in MC was compared with that observed in negative CNBD subjects.

RESULTS

Among 8006 colonoscopy, 305 subjects were enrolled for CNBD. Patients with CNBD were more likely to be women than men (odds ratio = 1.5; P = 0.001). Histopathology detected high prevalence of MC (16%) with a clear predominance of collagenous colitis (70%). A striking age-dependent rise in MC-associated risk was observed, depicting outstanding differences among varying age groups, as in the number needed to screen 1 new case. Gender distribution was balanced within MC patients (Female/Male = 1.5/1), especially among lymphocytic colitis (Female/Male = 1.2/1). MC patients were negatively associated with the risk of neoplastic polyps compared with negative CNBD subjects (odds ratio = 0.22; P = 0.035).

CONCLUSIONS

MC is the first cause of CNBD in subjects submitted to colonoscopy. Multiple biopsies are strongly recommended, even in the case of uneventful endoscopic inspection, especially for age ≥40 years. MC has a reduced risk of colorectal neoplasia, suggesting that this model of chronic inflammation plays a protective effect against colorectal carcinogenesis.

Endoscopic and clinical analysis of primary T-cell lymphoma of the gastrointestinal tract according to pathological subtype

BACKGROUND AND AIM

Little is known about the clinicopathological characteristics of primary gastrointestinal T-cell lymphomas (PGITL). This study evaluated the clinical and endoscopic features of the pathological subtypes of PGITL.

METHODS

Forty-two lesions in 36 patients with PGITL were assessed, including 15 enteropathy-associated T-cell lymphomas (EATL), 13 peripheral T-cell lymphomas (PTCL), 10 NK/T-cell lymphomas (NK/TL), and four anaplastic large cell lymphomas (ALCL).

RESULTS

PTCL occurred more frequently in the stomach and duodenum and NK/TL more frequently in the small and large intestines (P = 0.009). The endoscopic features of the four subtypes were similar (P = 0.124). Fifteen of 41 lesions (36.6%) were Epstein-Barr virus (EBV) positive, with NK/TL more likely to be EBV positive than the other types (P < 0.001). First endoscopy and first computed tomography (CT) scan indicated that 65.4% and 51.4% of the lesions, respectively, were malignant, and that 43.2% and 42.3%, respectively, were GI lymphomas. The two modalities together correctly diagnosed about half of the lesions before biopsy. Intestinal perforation was associated with small bowel location (P < 0.001) and infiltrative type (P = 0.009), and was more common in NK/TL than in the other subtypes (P = 0.015). Multivariate analysis showed that higher international prognosis index (P = 0.008) and the presence of complications (P = 0.006) were associated with poor prognosis. Survival was poorer in patients with small bowel lesions than with lesions at other locations (P = 0.048).

CONCLUSIONS

The four main pathological types of PGITL differed in clinical characteristics. As PGITL was often not diagnosed by initial endoscopic or radiological examination, a high index of suspicion is necessary to ensure its early diagnosis.

Chronic non-bloody diarrhoea: a prospective study in Malmö, Sweden, with focus on microscopic colitis

BACKGROUND

Chronic non-bloody diarrhoea affects up to 5% of the population. Microscopic colitis is one of the most common causes, encompassing the subtypes collagenous colitis and lymphocytic colitis. The diagnosis of microscopic colitis is made by histological examination of colonic mucosal biopsy specimens. The aim of this investigation was to determine whether laboratory parameters or questions about disease history or concomitant disease could be helpful in discriminating patients with MC from those with a histologically normal colonic mucosa.

FINDINGS

Patients admitted for colonoscopy because of chronic non-bloody diarrhoea (>2 loose stools for >3 weeks) at endoscopy units in Malmö during 2007 and 2009, were enrolled. A total number of 78 patients were included (60 women, 18 men, median age 59, IQR 45-69 years). Out of these 78, 15 patients (19%) had microscopic colitis (CC; n = 10, LC; n = 5). MC was especially prevalent in patients above the age of 50 (25%). No differences were found between those with normal histology and MC in laboratory analyses (inflammatory and liver parameters). Neither were differences shown in questions regarding symptoms, environmental factors or concomitant diseases except for an association with celiac disease (p = 0.019) and a trend maybe indicating an inverse association with appendectomy (p = 0.057).

CONCLUSIONS

Microscopic colitis is associated with female gender, celiac disease and consumption of NSAIDs. Trends were observed indicating that age above 50 years, acute onset and absence of appendectomy may be associated with MC. No associations were observed with other symptoms, calprotectin levels or liver parameters.

Diagnosing small bowel malabsorption: a review

Malabsorption encompasses dysfunctions occurring during the digestion and absorption of nutrients. A small proportion of patients presents with chronic diarrhoea. A clinical history supportive of malabsorption may guide investigations toward either the small bowel or pancreas. Serological testing for coeliac disease will determine most cases without invasive investigations. In the clinical context of persisting weight loss and malnutrition, small bowel enteropathy may be investigated with small intestinal biopsies. Small bowel absorptive capacity and permeability might be measured by oral sugar-mix ingestion. Further, approaches to the investigation of malabsorption might also involve the detection in faeces of a substance that has not been absorbed. A variation of the latter is the use of breath testing which relies on the breakdown of the malabsorbed test substance by colonic flora. Measurement of protein absorption is difficult and unreliable; it is, therefore, rarely advocated in clinical settings. No single biological marker confirming a diagnosis of small bowel malabsorption or small bowel integrity is presently available in clinical practice. Plasma citrulline concentration, an amino acid not incorporated into endogenous or exogenous proteins, has been extensively used in research studies and supportive results are establishing its concentration as a reliable quantitative biomarker of enterocyte absorptive capacity.

Gastro 2013 APDW/WCOG Shanghai working party report: chronic diarrhea: definition, classification, diagnosis

Diarrhea is best defined as passage of loose stools often with more frequent bowel movements. For clinical purposes, the Bristol Stool Form Scale works well to distinguish stool form and to identify loose stools. Laboratory testing of stool consistency has lagged behind. Acute diarrhea is likely to be due to infection and to be self-limited. As diarrhea becomes chronic, it is less likely to be due to infection; duration of 1 month seems to work well as a cut-off for chronic diarrhea, but detailed scientific knowledge is missing about the utility of this definition. In addition to duration of diarrhea, classifications by presenting scenario, by pathophysiology, and by stool characteristics (e.g. watery, fatty, or inflammatory) may help the canny clinician refine the differential diagnosis of chronic diarrhea. In this regard, a careful history remains the essential part of the evaluation of a patient with diarrhea. Imaging the intestine with endoscopy and radiographic techniques is useful, and biopsy of the small intestine and colon for histological assessment provides key diagnostic information. Endomicroscopy and molecular pathology are only now being explored for the diagnosis of chronic diarrhea. Interest in the microbiome of the gut is increasing; aside from a handful of well-described infections because of pathogens, little is known about alterations in the microbiome in chronic diarrhea. Serological tests have well-defined roles in the diagnosis of celiac disease but have less clearly defined application in autoimmune enteropathies and inflammatory bowel disease. Measurement of peptide hormones is of value in the diagnosis and management of endocrine tumors causing diarrhea, but these are so rare that these tests are of little value in screening because there will be many more false-positives than true-positive results. Chemical analysis of stools is of use in classifying chronic diarrhea and may limit the differential diagnosis that must be considered, but interpretation of the results is still evolving. Breath tests for assessment of carbohydrate malabsorption, small bowel bacterial overgrowth, and intestinal transit are fraught with technical limitations that decrease sensitivity and specificity. Likewise, tests of bile acid malabsorption have had limited utility beyond empirical trials of bile acid sequestrants.