Subtypes of irritable bowel syndrome in children and adolescents

Italian guidelines for the management of irritable bowel syndrome in children and adolescents : Joint Consensus from the Italian Societies of: Gastroenterology, Hepatology and Pediatric Nutrition (SIGENP), Pediatrics (SIP), Gastroenterology and Endoscopy (SIGE) and Neurogastroenterology and Motility (SINGEM)

The irritable bowel syndrome (IBS) is a functional gastrointestinal disorder (FGID), whose prevalence has widely increased in pediatric population during the past two decades. The exact pathophysiological mechanism underlying IBS is still uncertain, thus resulting in challenging diagnosis and management. Experts from 4 Italian Societies participated in a Delphi consensus, searching medical literature and voting process on 22 statements on both diagnosis and management of IBS in children. Recommendations and levels of evidence were evaluated according to the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus was reached for all statements. These guidelines suggest a positive diagnostic strategy within a symptom-based approach, comprehensive of psychological comorbidities assessment, alarm signs and symptoms' exclusion, testing for celiac disease and, under specific circumstances, fecal calprotectin and C-reactive protein. Consensus also suggests to rule out constipation in case of therapeutic failure. Conversely, routine stool testing for enteric pathogens, testing for food allergy/intolerance or small intestinal bacterial overgrowth are not recommended. Colonoscopy is recommended only in patients with alarm features. Regarding treatment, the consensus strongly suggests a dietary approach, psychologically directed therapies and, in specific conditions, gut-brain neuromodulators, under specialist supervision. Conditional recommendation was provided for both probiotics and specific fibers supplementation. Polyethylene glycol achieved consensus recommendation for specific subtypes of IBS. Secretagogues and 5-HT4 agonists are not recommended in children with IBS-C. Certain complementary alternative therapies, antispasmodics and, in specific IBS subtypes, loperamide and rifaximin could be considered.

Medical Insights from Posts About Irritable Bowel Syndrome by Adolescent Patients and Their Parents: Topic Modeling and Social Network Analysis

Background

Adolescents with irritable bowel syndrome (IBS) are increasingly seeking and sharing information about their symptoms in web-based health care forums. Their posts and those from their parents contain critical insights that can be used by patients, physicians, and caregivers to manage IBS symptoms.

Objective

The aim of this study is to examine the posts from adolescent patients and their parents in a health forum, IBS Group, to better understand the key challenges, concerns, and issues of interest to young patients with IBS and their caregivers.

Methods

Using topic modeling and social network analysis, in this study, we analyzed all the messages (over 750 topics and 3400 replies) posted on the IBS Group forum from 2010-2019 by adolescents with IBS aged 13-17 years and parents having children with IBS. We first detected 6 major topics in the posts by adolescent patients and parents on teenagers’ IBS symptoms and the interaction between the topics. Social network analysis was then performed to gain insights into the nature of web-based interaction patterns among patients and caregivers.

Results

Using the Latent Dirichlet Allocation algorithm and a latent Dirichlet allocation visualization tool, this study revealed 6 leading topics of concern in adolescents with IBS: school life, treatment or diet, symptoms, boys’ ties to doctors, social or friend issues, and girls’ ties to doctors. The top 6 topics in the parents’ discussions were school life, girls’ issues, boys’ issues, diet choice, symptoms, and stress. The analyses show that the adolescent patients themselves are most concerned about the effect of IBS on their everyday activities and social lives. For parents having daughters with IBS, their top concerns were related to the girls’ school performance and how much help they received at school. For their sons, the parents were more concerned about the pain and suffering that their sons had to endure. Both parents and adolescents gained social support from the web-based platform. Topic modeling shows that IBS affects teenagers the most in the areas of pain and school life. Furthermore, the issues raised by parents suggest that girls are bothered more by school performance over pain, whereas boys show exactly the opposite: pain is of greater concern than school performance.

Conclusions

This study represents the first attempt to leverage both machine learning approaches and social network analysis to identify top IBS concerns from the perspectives of adolescent patients and caregivers in the same health forum. Young patients with IBS must face the challenges of social influences and anxiety associated with this health disorder in addition to physical pain and other symptoms. Boys and girls are affected differently by pain and school performance and view the IBS impacts differently from the parents.

Markers of Bile Acid Metabolism in Pediatric Diarrhea Predominant Irritable Bowel Syndrome and Healthy Controls

OBJECTIVES

Excessive fecal bile acids in adults have been associated with diarrhea-predominant irritable bowel syndrome (IBS-D), but their role in pediatric IBS-D is unknown. Serum markers including 7α-hydroxy-4-cholesten-3-one (C4) and fibroblast growth factor-19 (FGF-19) were validated in adults to detect bile acid diarrhea (BAD) compared to 48-hour fecal bile acid collection (48FBA). Our aims were to assess fasting serum C4 and FGF-19 and 48FBA in a pediatric population, to compare measurements in IBS-D patients and healthy controls (HC), and to determine the prevalence of BAD among children with IBS-D.

METHODS

Using a cross-sectional design, 26 patients with IBS-D and 56 HC were recruited in two pediatric tertiary care centers. Fasting serum C4 and FGF-19 and 48FBA were obtained. Participants completed a 7-day bowel diary coinciding with stool collection. Associations were analyzed using Spearman correlations.

RESULTS

Mean age was 14.7 ± 2.5 years (42.3% female) in IBS-D and 12.6 ± 2.4 years (39.3% female) in HC. There was a significant correlation of C4 with 48FBA (r = 0.48, P < 0.05) and an inverse association with FGF-19 (r = -0.43, P < 0.05). No significant differences were noted in C4 (P = 0.32), FGF-19 (P = 0.1), or 48FBA (P = 0.5) between IBS-D and HC groups; however, 20% of IBS-D patients had elevated C4 and 28% had low FGF-19 values.Fecal primary BA was significantly correlated with stool frequency (r = 0.45, P < 0.002).

CONCLUSIONS

Correlations of C4 with 48FBA and FGF-19 are confirmed in a pediatric population. Twenty percent of pediatric patients with IBS-D had abnormal fasting serum C4. This serum test could be applied to identify BAD in pediatric IBS-D.

Irritable bowel syndrome in Indonesian adolescents

OBJECTIVE

Irritable bowel syndrome is a frequent functional gastrointestinal disorder. The aims of this study were to investigate its epidemiology, focusing on the role of intestinal mucosal integrity and to evaluate the impact on the quality of life.

METHODS

A community-based survey applying a comparative cross sectional approach was conducted in six high schools in Palembang. Subjects were recruited using multistage random sampling divided in two groups. Rome III criteria were used to establish a diagnosis of IBS in combination with a questionnaire to determine risk factors. Determination of fecal alpha-1-antitrypsin and calprotectin levels was performed to determine impaired intestinal mucosal integrity. A questionnaire was used to evaluate how quality of life was affected by irritable bowel syndrome.

RESULTS

The survey was performed in 454 14-18years old adolescents, of whom 30.2% fulfilled the Rome III criteria for IBS, with the following subtypes: 36.5% diarrhea, 18.9% constipation, 21.9% mixed, and 22.6% unclassified. Major risk factors were female gender, bullying, age 14-16 years, history of constipation and diarrhea, eating nuts, and drinking coffee, tea, and soft drinks. There was a significant association with intestinal inflammation (p=0.013). A significantly impaired quality of life was found (p=0.001).

CONCLUSIONS

The prevalence of irritable bowel syndrome in adolescents was high, with bullying, female gender, age 14-16 years, constipation and diarrhea, and dietary consumption of soft drinks, coffee, and tea as risk factors. A significant association with intestinal inflammation was found.

Differential Effects of Sucrase-Isomaltase Mutants on Its Trafficking and Function in Irritable Bowel Syndrome: Similarities to Congenital Sucrase-Isomaltase Deficiency

Congenital sucrase-isomaltase deficiency (CSID) is a rare metabolic intestinal disorder with reduced or absent activity levels of sucrase-isomaltase (SI). Interestingly, the main symptoms of CSID overlap with those in irritable bowel syndrome (IBS), a common functional gastrointestinal disorder with unknown etiology. Recent advances in genetic screening of IBS patients have revealed rare SI gene variants that are associated with IBS. Here, we investigated the biochemical, cellular and functional phenotypes of several of these variants. The data demonstrate that the SI mutants can be categorized into three groups including immature, mature but slowly transported, and finally mature and properly transported but with reduced enzymatic activity. We also identified SI mutant phenotypes that are deficient but generally not as severe as those characterized in CSID patients. The variable effects on the trafficking and function of the mutations analyzed in this study support the view that both CSID and IBS are heterogeneous disorders, the severity of which is likely related to the biochemical phenotypes of the SI mutants as well as the environment and diet of patients. Our study underlines the necessity to screen for SI mutations in IBS patients and to consider enzyme replacement therapy as an appropriate therapy as in CSID.

The Prevalence of Hypermobility in Children with Irritable Bowel Syndrome and Functional Abdominal Pain Is Similar to that in Healthy Children

OBJECTIVES

To test the hypothesis that the prevalence of joint hypermobility is greater in children with irritable bowel syndrome and functional abdominal pain than in healthy control children and is related to gastrointestinal symptoms and psychosocial distress (anxiety, depression, and somatization).

STUDY DESIGN

Children (irritable bowel syndrome, n = 109; functional abdominal pain, n = 31; healthy control, n = 69), 7-12 years of age completed prospective 2-week pain and stooling diaries and child- and parent-reported measures of anxiety, depression, and somatization. Joint hypermobility was determined using Beighton criteria (score of ≥4 or 6). We also examined possible relationships between Beighton score, race, body mass index, gastrointestinal symptoms, and psychosocial distress.

RESULTS

Beighton scores were similar between groups, as was the proportion with joint hypermobility. Scores were higher in girls (3.1 ± 2.4) than boys (2.3 ± 1.8; P = .004) and decreased with age (P < .001; r = -0.25). Race and body mass index did not impact joint hypermobility prevalence. Beighton scores were not related to abdominal pain or stooling characteristics. Participants with a score of ≥4 and ≥6 had greater somatization and depression by child report (P = .017 and P = .048, respectively). No association was seen for anxiety. There was no significant association between joint hypermobility and psychosocial distress measures per parent report.

CONCLUSIONS

Contrary to the adult literature, the prevalence of joint hypermobility does not differ among children with irritable bowel syndrome, functional abdominal pain, or healthy control children. The presence or severity of joint hypermobility does not correlate with abdominal pain or stooling characteristics. Somatization and depression by child report appear to have a relationship with joint hypermobility.

The Effects of the Rome IV Criteria on Pediatric Gastrointestinal Practice

PURPOSE OF REVIEW

To evaluate the impact of the implementation of the Rome IV criteria on pediatric gastrointestinal practice.

RECENT FINDINGS

In 2016, the Rome IV criteria were published, providing an update of symptom-based criteria to diagnose children with functional gastrointestinal disorders (FGIDs). For neonates and toddlers, Wessel's criteria for diagnosing infant colic were abandoned, and a differentiation was made between toilet-trained and non-toilet-trained children in the diagnosis of functional constipation. For children and adolescents, two new disorders (functional nausea and functional vomiting) are described, and in the diagnosis of functional dyspepsia, pain does not have to be the chief complaint anymore. This change has made functional dyspepsia the most common functional abdominal pain disorder, exceeding the prevalence of irritable bowel syndrome (IBS). Lastly, the diagnosis of abdominal migraine was narrowed, causing an appropriate drop in its prevalence.

'Rapid transit' constipation in children: a possible genesis for irritable bowel syndrome

Children with chronic idiopathic constipation (CIC) often end up at the surgeon when medical treatments have failed. This opinion piece discusses a recently described pattern of CIC called 'Rapid transit constipation (RTC)' first identified in 2011 as part of surgical workup. RTC was identified using a nuclear medicine gastrointestinal transit study (NMGIT or nuclear transit study) to determine the site of slowing within the bowel and to inform surgical treatment. Unexpectedly, we found that RTC occured in 29% of 1000 transit studies in a retrospective audit. Irritable bowel syndrome (IBS) occurs in 7-21% of the population, with a higher prevalence in young children and with constipation type dominating in the young. While 60% improve with time, 40% continue with symptoms. First-line therapy for IBS in adults is a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols which reduces symptoms in > 70% of patients. In children with functional gastrointestinal disorders, fructose intolerance occurs in 35-55%. Reducing fructose produced significant improvement in 77-82% of intolerant patients. In children with RTC and a positive breath test upon fructose challenge, we found that exclusion of fructose significantly improved constipation, abdominal pain, stool consistency and decreased laxative use. We hypothesise that positive breath tests and improvement of pain and bowel frequency with sugar exclusion diets in RTC suggest these children have IBS-C. These observations raise the possibility that many children with CIC could be treated by reducing fructose early in their diet and this might prevent the development of IBS in later life.

Subtipos del síndrome de intestino irritable en niños

La prevalencia del síndrome de intestino irritable (SII) pediátrico es 1,2%-5,4%, y los subtipos en niños latinoamericanos, no está especificada. El objetivo de este estudio es caracterizar los subtipos del SII y sus posibles asociaciones. Estudio de prevalencia en niños entre los ocho y 18 años de edad con SII según los Criterios de Roma III. Se tomaron variables sociodemográficas, familiares y clínicas. Los subtipos de SII se consideraron por la consistencia de las heces en SII con estreñimiento (SII-e); diarrea (SII-d); mixto (SII-m) y sin subtipo (SII-ss). La estadística incluyó análisis uni y bivariados. Los datos fueron analizados usando t-student a dos colas, chi2, prueba exacta de Fisher y razón de prevalencia (RP) con IC95%, siendo p<0,05 significativa. Fueron incluidos 196 niños (53,6% femeninos; mediana de 11 años); presentándose SII-ss en 64,8%, SII-e en 19,9%, SII-m en 8,7% y SII-d en 6,6%. Hubo diferencias significativas en las características de las heces (p=0,01), en la incontinencia fecal (p=0,02), en los fecalomas (p=0,00); y posibles asociaciones entre el SII-d, ciudad (p=0,00) y malnutrición (p=0,02). En conclusión, luego del SII-ss, ¼ de los niños estudiados presentó SII-e, seguido del SII-m y SII-d; presentándose el SII-d con mayor oportunidad en malnutridos.

Is fecal calprotectin always normal in children with irritable bowel syndrome?

Background/Aims

Fecal calprotectin (FC) is a marker of intraluminal intestinal inflammation. Intestinal inflammation may contribute to the pathophysiology of irritable bowel syndrome (IBS). This study evaluated FC levels in children with IBS and differences in FC levels in children stratified by IBS subtype and healthy controls (HCs).

Methods

A total of 157 children with IBS and 56 HCs aged 4–16 years (119 boys, 94 girls, mean age of 9.48 years) were included in this prospective study. Children with IBS were diagnosed using the Rome III criteria and classified into 4 subtypes: IBS with constipation (IBS-C, n=37), IBS with diarrhea (IBS-D, n=54), IBS with alternating constipation and diarrhea (IBS-M, n=49), and IBS unsubtyped (IBS-U, n=17); postinfectious IBS (PI-IBS) was also considered. The FC concentration in stool samples was analyzed using an enzyme-linked immunosorbent assay. All participants answered a questionnaire regarding several demographic and clinical characteristics.

Results

Children with IBS had significantly higher levels of FC than the HCs (88.71 μg/g vs. 17.77 μg/g). Among the 4 IBS subtypes, the FC concentration was highest in children with IBS-D, followed by those with IBS-M, IBS-C, and IBS-U (169.94 μg/g vs. 45.04, 31.22, and 33.52 μg/g, respectively), and these differences were statistically significant. For PI-IBS, 90% of cases were in the IBS-D group.

Conclusions

The FC level was significantly higher in children with IBS than in HCs and differed depending on the IBS subtype, supporting the notion that IBS is a type of low-grade bowel inflammation.

Blastocystis ST-1 is associated with Irritable Bowel Syndrome-diarrhoea (IBS-D) in Indonesian adolescences

Objective

IBS is a functional gastrointestinal disorder and commonly presents in children and adolescences, presented as diarrhoea, constipation or mixed type. Blastocystis is a common intestinal protozoa found worldwide, which pathogenicity is still controversial. This study aimed to identify the risk factors of IBS, the association between IBS types with Blastocystis subtypes and analyse Blastocystis pathogenicity.

Design

A comparative cross-sectional study was conducted among senior high school students. Rome III Criteria for IBS diagnosis, questionnaires on the risk factors of IBS and types of IBS were recorded. Students were further selected and classified into IBS and non-IBS groups to analyse the association between IBS, IBS types with Blastocystis infection and its subtypes. Direct microscopic stool examination to identify single Blastocystis infection was performed, followed by culture in Jones' medium, PCR, sequencing of 18S rRNA and phylogenetic analysis to determine Blastocystis subtype. Data was analysed using SPSS v22.0 and P value <0.05 was considered statistically significant (95% confidence intervals).

Results

IBS was found in 30.2% of 454 students, consisted of 33.3% IBS Diarrhoea, 27.7% IBS Mixed, 27.7% IBS Unclassified and 11.1% IBS Constipation. Major risk factors to IBS consisted of family history of recurrent abdominal pain, abuse, bullying and female gender in respective order (OR 3.6–2.1). Blastocystis ST-1 was significantly associated to IBS-D with 2.9 times risk factor.

Conclusions

Blastocystis infection is a risk factor to develop IBS-D type in adolescence; Blastocystis ST-1 can be regarded as a pathogenic subtype.

Leveraging Human Microbiome Features to Diagnose and Stratify Children with Irritable Bowel Syndrome

Accurate diagnosis and stratification of children with irritable bowel syndrome (IBS) remain challenging. Given the central role of recurrent abdominal pain in IBS, we evaluated the relationships of pediatric IBS and abdominal pain with intestinal microbes and fecal metabolites using a comprehensive clinical characterization and multiomics strategy. Using rigorous clinical phenotyping, we identified preadolescent children (aged 7 to 12 years) with Rome III IBS (n = 23) and healthy controls (n = 22) and characterized their fecal microbial communities using whole-genome shotgun metagenomics and global unbiased fecal metabolomic profiling. Correlation-based approaches and machine learning algorithms identified associations between microbes, metabolites, and abdominal pain. IBS cases differed from controls with respect to key bacterial taxa (eg, Flavonifractor plautii and Lachnospiraceae bacterium 7_1_58FAA), metagenomic functions (eg, carbohydrate metabolism and amino acid metabolism), and higher-order metabolites (eg, secondary bile acids, sterols, and steroid-like compounds). Significant associations between abdominal pain frequency and severity and intestinal microbial features were identified. A random forest classifier built on metagenomic and metabolic markers successfully distinguished IBS cases from controls (area under the curve, 0.93). Leveraging multiple lines of evidence, intestinal microbes, genes/pathways, and metabolites were associated with IBS, and these features were capable of distinguishing children with IBS from healthy children. These multi-omics features, and their links to childhood IBS coupled with nutritional interventions, may lead to new microbiome-guided diagnostic and therapeutic strategies.

Elimination of Fermentable Carbohydrates to Reduce Gastrointestinal Symptoms in Pediatric Patients With Irritable Bowel Syndrome: A Narrative Review

Irritable bowel syndrome (IBS) is classified as a functional gastrointestinal (GI) disorder characterized by abdominal pain, bloating, and changes in bowel function. Although the pathophysiology of IBS is incompletely understood, fermentable carbohydrates are implicated as a potential cause of symptoms. An elimination diet, such as a low-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet, represents a potential intervention for reducing GI symptoms in patients with IBS. The role of fermentable carbohydrates in symptom onset is well studied in adult patients with IBS; however, less research exists in the pediatric population. This review sought to explore evidence for the role of dietary fermentable carbohydrate elimination to reduce GI symptoms (abdominal pain, stool changes, abdominal bloating) in children and adolescents (4-19 years of age) diagnosed with IBS based on Rome III or IV criteria. Five studies of neutral to positive quality rating were identified and analyzed using the Academy of Nutrition and Dietetics Evidence Analysis Process. These studies demonstrate that dietary elimination of fermentable carbohydrates, such as through a low-FODMAP diet, reduces the severity of 1 or more GI symptoms in about one-quarter to one-half of pediatric patients with IBS. Patients without improvement are considered "nonresponders" and may require an alternative intervention. More research is needed to establish the best way to identify patients who would respond to elimination diets vs other IBS treatment strategies.

Evidence of increased fecal granins in children with irritable bowel syndrome and correlates with symptoms

BACKGROUND

Granins have been implicated in the pathophysiology of irritable bowel syndrome (IBS) in adults. We sought to determine whether fecal granins are altered in children with IBS and associated with symptoms.

METHODS

Children (7-12 years of age) with IBS and healthy controls (HC) kept daily pain and stool diaries for 2 weeks. Stool samples were analyzed for chromogranins A and B (CgA, CgB) and secretogranins II and III (SgII, SgIII). Children also completed psychological measures to assess anxiety, depression, somatization, and internalizing symptoms.

KEY RESULTS

Fecal CgB and SgIII concentrations were higher in all the boys (IBS plus HC, n = 48) than in all the girls (IBS plus HC, n = 75) (P = 0.02 and P = 0.046, respectively). CgA and SgIII were greater in children with IBS (n = 52) vs HC (n = 69) (P = 0.01, P = 0.017, respectively). CgB and SgII did not differ between groups. In children with IBS, the number of pain episodes per week and mean daily pain rating correlated positively with all four granins. The number of stools per day correlated positively with CgB and SgII, and the percent of diarrheal stools (6 or 7 on the Bristol Scale) correlated inversely with all four granins in boys but not in girls. Fecal granins did not correlate with psychological measures.

CONCLUSIONS AND INFERENCES

As measured by fecal granins, there is evidence of neuroimmune activation in children with IBS. Granins are related to abdominal pain symptoms, stooling frequency, and stool form in children with IBS. Sex influences the fecal concentration of CgB and SgIII.

AAPT Diagnostic Criteria for Chronic Abdominal, Pelvic, and Urogenital Pain: Irritable Bowel Syndrome

In conjunction with the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks public-private partnership with the U.S. Food and Drug Administration and the American Pain Society, the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks-American Pain Society Pain Taxonomy (AAPT) initiative strove to develop the characteristics of a diagnostic system useful for clinical and research purposes across disciplines and types of chronic pain conditions. After the establishment of these characteristics, a working group of clinicians and clinical and basic scientists with expertise in abdominal, pelvic, and urogenital pain began generating core diagnostic criteria and defining the related extraintestinal somatic pain and other symptoms experienced by patients. Systematic diagnostic criteria for several common abdominal, pelvic, and urogenital pain conditions are in development. In this report, we present the proposed AAPT criteria for irritable bowel syndrome (IBS), the most common chronic, noncancer abdominal pain condition. A systematic review and synthesis was conducted to complement the Rome IV Diagnostic Criteria for IBS. Future efforts will subject these proposed AAPT criteria to systematic empirical evaluation of their feasibility, reliability, and validity. The AAPT IBS criteria are part of an evidence-based classification system that provides a consistent vocabulary regarding diagnostic criteria, common features, comorbidities, consequences, and putative mechanisms of the disorder. A similar approach is being applied to other chronic and often debilitating abdominal, pelvic, and urogenital pain conditions.

PERSPECTIVE

The AAPT's goal is to develop an evidence-based taxonomy for chronic pain on the basis of a consistently applied multidimensional framework, and encourage experts to apply this taxonomy to specific chronic pain conditions. In this report, the taxonomy is applied to IBS, a chronic abdominal pain condition.

Lactulose Breath Test Gas Production in Childhood IBS Is Associated With Intestinal Transit and Bowel Movement Frequency

OBJECTIVES

In adults with irritable bowel syndrome (IBS), bacterial gas production (colonic fermentation) is related to both symptom generation and intestinal transit. Whether gas production affects symptom generation, psychosocial distress, or intestinal transit in childhood IBS is unknown.

METHODS

Children (ages 7-17 years) with pediatric Rome III IBS completed validated psychosocial questionnaires and a 2-week daily diary capturing pain and stooling characteristics. Stool form determined IBS subtype. Subjects then completed a 3-hour lactulose breath test for measurement of total breath hydrogen and methane production. Carmine red was used to determine whole intestinal transit time.

RESULTS

A total of 87 children (mean age 13 ± 2.6 [standard deviation] years) were enrolled, of whom 50 (57.5%) were girls. All children produced hydrogen and 51 (58.6%) produced methane. Hydrogen and methane production did not correlate with either abdominal pain frequency/severity or psychosocial distress. Hydrogen and methane production did not differ significantly by IBS subtype. Methane production correlated positively with whole intestinal transit time (r = 0.31, P < 0.005) and inversely with bowel movement frequency (r = -0.245, P < 0.05). Methane production (threshold 3 ppm) as a marker for identifying IBS-C had a sensitivity of 60% and specificity of 42.9%.

CONCLUSIONS

Lactulose breath test total methane production may serve as a biomarker of whole intestinal transit time and bowel movement frequency in children with IBS. In children with IBS, lactulose breath test hydrogen and methane production did not, however, correlate with abdominal pain, IBS subtype, or psychosocial distress.

Childhood Irritable Bowel Syndrome Characteristics Are Related to Both Sex and Pubertal Development

OBJECTIVE

To determine the relationship of both pubertal development and sex to childhood irritable bowel syndrome (IBS) clinical characteristics including gastrointestinal symptoms (eg, abdominal pain) and psychological factors.

STUDY DESIGN

Cross-sectional study with children ages 7-17 years (n = 143) with a pediatric Rome III IBS diagnosis recruited from both primary and tertiary clinics between January 2009 and January 2014. Subjects completed 14-day prospective pain and stool diaries, as well as validated questionnaires assessing several psychological factors (somatization, depression, anxiety) and Tanner stage. Stool form ratings were completed using the Bristol Stool Form Scale.

RESULTS

Girls with higher Tanner scores (more mature pubertal development) had both decreased pain severity and pain interference; in contrast, boys with higher Tanner scores had both increasing pain severity (β = 0.40, P = .02) and pain interference (β = 0.16, P = .02). Girls (vs boys), irrespective of pubertal status, had both increased somatic complaints (P = .005) and a higher percentage (P = .01) of hard (Bristol Stool Form Scale type 1 or 2) stools. Pubertal status and sex did not significantly relate to IBS subtype, pain frequency, stooling frequency, anxiety, or depression.

CONCLUSIONS

In children with IBS, both pubertal development and/or sex are associated with abdominal pain severity, stool form, and somatization. These differences provide insight into the role of pubertal maturation during the transition from childhood to adult IBS.

Underlying molecular and cellular mechanisms in childhood irritable bowel syndrome

Irritable bowel syndrome (IBS) affects a large number of children throughout the world. The symptom expression of IBS is heterogeneous, and several factors which may be interrelated within the IBS biopsychosocial model play a role. These factors include visceral hyperalgesia, intestinal permeability, gut microbiota, psychosocial distress, gut inflammation, bile acids, food intolerance, colonic bacterial fermentation, and genetics. The molecular and cellular mechanisms of these factors are being actively investigated. In this mini-review, we present updates of these mechanisms and, where possible, relate the findings to childhood IBS. Mechanistic elucidation may lead to the identification of biomarkers as well as personalized childhood IBS therapies.

Recommendations for pharmacological clinical trials in children with irritable bowel syndrome: the Rome foundation pediatric subcommittee on clinical trials

BACKGROUND

There is little published evidence of efficacy for the most commonly used treatments. Thus, there is an urgent need to conduct clinical trials on existing and novel therapies.

PURPOSE

In order to address these issues the Rome Foundation and members of the Pediatric Committee of the European Medicines Agency formed a subcommittee on clinical trials to develop guidelines for the design of clinical trials in children with irritable bowel syndrome (IBS). The following recommendations are based on evidence from published data when available and expert opinion.

KEY RECOMMENDATIONS

The subcommittee recommends randomized, double-blind, placebo-controlled, parallel-group, clinical trials to assess the efficacy of new drugs. The combined endpoints for abdominal pain are a decrease in intensity of at least 30% compared with baseline and to meet or exceed the Reliable Change Index (RCI) for the sample. Stool consistency is measured with the Bristol Stool Scale Form (BSFS). The subcommittee recommends as entry criteria for abdominal pain a weekly average of worst abdominal pain in past 24 h of at least 3.0 on a 0-10 point scale or at least 30 mm in 100 mm Visual Analog Scale. For stool endpoints the committee recommends an average stool consistency lower than 3 in the BSFS during the run-in period for clinical trials on IBS-C and an average stool consistency greater than 5 in the BSFS during the run-in period for clinical trials on IBS-D. Changes in stool consistency are the primary endpoints for both IBS with diarrhea (IBS-D) and IBS with constipation (IBS-C).

Gastrointestinal symptoms predictors of health-related quality of life in pediatric patients with functional gastrointestinal disorders

OBJECTIVES

To investigate the patient-reported multidimensional gastrointestinal symptoms predictors of generic health-related quality of life (HRQOL) in pediatric patients with functional gastrointestinal disorders (FGIDs).

METHODS

The Pediatric Quality of Life Inventory™ (PedsQL™) Gastrointestinal Symptoms Scales and PedsQL™ 4.0 Generic Core Scales were completed in a 9-site study by 259 pediatric patients with functional constipation, functional abdominal pain (FAP), or irritable bowel syndrome (IBS). Gastrointestinal Symptoms Scales measuring stomach pain, stomach discomfort when eating, food and drink limits, trouble swallowing, heartburn and reflux, nausea and vomiting, gas and bloating, constipation, blood in poop, and diarrhea were identified as clinically important symptom differentiators from healthy controls based on prior findings, and subsequently tested for bivariate and multivariate linear associations with overall HRQOL.

RESULTS

Gastrointestinal symptoms were differentially associated with decreased HRQOL in bivariate analyses for the three FGIDs. In predictive models utilizing hierarchical multiple regression analyses controlling for age, gender, and race/ethnicity, gastrointestinal symptoms differentially accounted for an additional 47, 40, and 60 % of the variance in patient-reported HRQOL for functional constipation, FAP, and IBS, respectively, reflecting large effect sizes. Significant individual gastrointestinal symptoms predictors were identified after controlling for the other gastrointestinal symptoms in the FGID-specific predictive models.

CONCLUSIONS

Gastrointestinal symptoms represent potentially modifiable predictors of generic HRQOL in pediatric patients with FGIDs. Identifying the condition-specific gastrointestinal symptoms that are the most important predictors from the patient perspective facilitates a patient-centered approach to targeted interventions designed to ameliorate impaired overall HRQOL.

Self-Perceived Food Intolerances Are Common and Associated with Clinical Severity in Childhood Irritable Bowel Syndrome

BACKGROUND

Adults with irritable bowel syndrome (IBS) frequently identify foods as exacerbating their gastrointestinal symptoms. In children with IBS, the prevalence of perceived food intolerances and their impact are unknown.

OBJECTIVE

Our aim was to determine the prevalence of self-perceived food intolerances and the relationship of these intolerances to abdominal pain, psychosocial distress, and quality of life in children with IBS.

DESIGN

We conducted a cross-sectional study. Questionnaire and prospective diary data were collected from 2008 to 2014 by trained research coordinators.

PARTICIPANTS/SETTING

Participants were children 7 to 18 years old (pediatric Rome III IBS, n=154; age-sex matched healthy children, n=32) in Houston, TX.

MEASURES

Perceived food intolerances and avoided foods were captured using the Childhood Food and Symptom Association Questionnaire. IBS severity was assessed by a ≥7-day pain diary and validated psychosocial questionnaires assessing quality of life, somatization, functional disability, depression, and anxiety.

STATISTICAL ANALYSES PERFORMED

We used descriptive Spearman bivariate correlation, χ(2), and Poisson log-linear generalized model with Wald χ(2) statistics.

RESULTS

A greater proportion of children with IBS (143 of 154 [92.9%]) vs healthy children (20 of 32 [62.5%]) identified at least one self-perceived food intolerance (χ(2)=22.5; P<0.001). Children with IBS identified a greater number (median=4 [25% to 75% quartile=2 to 6]) of perceived symptom-inducing foods than healthy children (median=2 [25% to 75% quartile=0 to 4]; χ(2)=28.6; P<0.001). Children with IBS avoided more foods (median=2 [25% to 75% quartile=1 to 4]) than healthy children (median=0 [25% to 75% quartile=0 to 2.75]; χ(2)=20.8; P<0.001). The number of self-perceived food intolerances was weakly associated (r value range= -0.17 to 0.21) with pain frequency, pain severity, somatization, anxiety, functional disability, and decreased quality of life.

CONCLUSIONS

Children with IBS have a high prevalence of self-perceived food intolerances. The number of these intolerances is weakly associated with measures of IBS severity.

Bristol Stool Form Scale reliability and agreement decreases when determining Rome III stool form designations

BACKGROUND

Rater reproducibility of the Bristol Stool Form Scale (BSFS), which categorizes stools into one of seven types, is unknown. We sought to determine reliability and agreement by individual stool type and when responses are categorized by Rome III clinical designation as normal or abnormal (constipation or diarrhea).

METHODS

Thirty-four gastroenterology providers from three institutions rated 35 stool photographs using the BSFS. Twenty rerated the photographs.

KEY RESULTS

1190 individual stool type ratings were completed. Though only four photographs had absolute agreement (all Type 1 or Type 7), general agreement was high with 1132 (95.1%) of ratings being within one category type of the modal rating. Inter-rater and intra-rater reliability of the BSFS by individual stool type was excellent with intraclass correlations of 0.88 (95% CI: 0.86-0.90, p < 0.001) and 0.89 (95% CI: 0.86-0.91, p < 0.001), respectively. However, agreement decreased when using Rome III designations with 13 (37%) photographs having significantly diverging classifications (semi-interquartile range = 0.5). These 13 photographs were rated by the majority of raters as either type 2 vs type 3 or type 5 vs type 6 stools, representing the boundaries of normal vs abnormal stools. Inter-rater and intra-rater reliability of the BSFS by Rome III clinical categorization decreased with intraclass correlations of 0.75 (95% CI: 0.69-0.81, p < 0.001) and 0.65 (95% CI: 0.49-0.81, p < 0.001), respectively.

CONCLUSIONS & INFERENCES

The Bristol Stool Form Scale has excellent reliability and agreement when used to rate individual stool type by raters. However, BSFS reliability and agreement decreases when determining Rome III stool form categories.

High Prevalence of Nausea among School Children in Latin America

OBJECTIVES

To evaluate the prevalence of nausea and its association with functional gastrointestinal disorders (FGIDs) in a large-scale, population-based study of Latin American school children.

STUDY DESIGN

This cross-sectional study collected data from children in 3 Latin American countries. A Spanish version of the Questionnaire on Pediatric Gastrointestinal Symptoms-Rome III Version (QPGS-III) was administered to school children in Central and South America. Subjects were classified into FGIDs based on Rome criteria (QPGS-III). Students from 4 public and 4 private schools in the countries of El Salvador, Panama, and Ecuador participated in this epidemiologic study.

RESULTS

A total of 1137 school children with mean age 11.5 (SD 1.9, range 8-15) years completed the QPGS-III (El Salvador n = 399; Panama n = 321; Ecuador n = 417). Nausea was present in 15.9% of all school children. Two hundred sixty-eight (24%) children met criteria for at least 1 FGID. Nausea was significantly more common in children with FGIDs compared with those without: El Salvador 38% vs 15% (P < .001); Panama 22% vs 7% (P < .001); Ecuador 25% vs 13% (P = .004). Among children with FGIDs, those with functional constipation had a high prevalence of nausea. Nausea was significantly more common in girls and children attending private schools.

CONCLUSIONS

Nausea is commonly present in Latin American school children. FGIDs are frequently associated with nausea.

Present state and future challenges in pediatric abdominal pain therapeutics research: Looking beyond the forest

At the present time, it is nearly impossible to treat pediatric functional gastrointestinal disorders associated with pain in an evidence based fashion. This is due to the overall lack of controlled studies and, even more importantly, the complexity of the contributors to disease phenotype which are not controlled or accounted for in most therapeutic trials. In this manuscript, we review the challenges of defining entry criteria, controlling for the large number of biopsychosocial factors which may effect outcomes, and understanding pharmacokinetic and pharmacodynamic factors when designing therapeutic trials for abdominal pain in children. We also review the current state of pediatric abdominal pain therapeutics and discuss trial design considerations as we move forward.

Pediatric Functional Constipation Gastrointestinal Symptom Profile Compared With Healthy Controls

OBJECTIVES

Patient-reported outcomes are necessary to evaluate the gastrointestinal symptom profile of patients with functional constipation. Study objectives were to compare the gastrointestinal symptom profile of pediatric patients with functional constipation with matched healthy controls with the Pediatric Quality of Life Inventory Gastrointestinal Symptoms and Gastrointestinal Worry Scales and to establish clinical interpretability in functional constipation through identification of minimal important difference (MID) scores. The secondary objective compared the symptom profile of patients with functional constipation with patients with irritable bowel syndrome (IBS).

METHODS

Gastrointestinal Symptoms and Worry Scales were completed in a 9-site study by 116 pediatric patients with functional constipation and 188 parents. Gastrointestinal Symptoms Scales measuring stomach pain, stomach discomfort when eating, food and drink limits, trouble swallowing, heartburn and reflux, nausea and vomiting, gas and bloating, constipation, blood in poop, and diarrhea were administered along with Gastrointestinal Worry Scales. A total of 341 families with healthy children and 43 families with patients with IBS completed the scales.

RESULTS

A broad profile of gastrointestinal symptoms and worry were reported by patients with functional constipation in comparison with healthy controls (P < 0.001) with large effect sizes (>0.80) across the majority of symptom domains. Patients with IBS manifested a broader symptom profile than functional constipation, with differences for stomach pain, stomach discomfort when eating, and worry about stomachaches, with similar constipation scores.

CONCLUSIONS

Pediatric patients with functional constipation report a broad gastrointestinal symptom profile in comparison with healthy controls and only somewhat fewer symptoms than patients with IBS, highlighting the critical need for more efficacious interventions to achieve healthy functioning.

Symptom Profiles in Patients With Irritable Bowel Syndrome or Functional Abdominal Pain Compared With Healthy Controls

OBJECTIVES

Patient-reported outcome (PRO) measures of gastrointestinal symptoms are recommended to determine treatment effects for irritable bowel syndrome (IBS) and functional abdominal pain (FAP). Study objectives were to compare the symptom profiles of pediatric patients with IBS or FAP with healthy controls and with each other using the PedsQL Gastrointestinal Symptoms and Gastrointestinal Worry Scales, and to establish clinical interpretability of PRO scale scores through identification of minimal important difference (MID) scores.

METHODS

Gastrointestinal Symptoms and Worry Scales were completed in a 9-site study by 154 pediatric patients and 161 parents (162 families; IBS n = 46, FAP n = 119). Gastrointestinal Symptoms Scales measuring stomach pain, stomach discomfort when eating, food and drink limits, trouble swallowing, heartburn and reflux, nausea and vomiting, gas and bloating, constipation, blood in poop, and diarrhea were administered along with Gastrointestinal Worry Scales. A matched sample of 447 families with healthy children completed the scales.

RESULTS

Gastrointestinal Symptoms and Worry Scales distinguished between patients with IBS or FAP compared with healthy controls (P < 0.001), with larger effect sizes (>1.50) for symptoms indicative of IBS or FAP, demonstrating a broad multidimensional gastrointestinal symptom profile and clinical interpretability with MID scores for individual PRO scales. Patients with IBS manifested more symptoms of constipation, gas and bloating, and diarrhea than patients with FAP.

CONCLUSIONS

Patients with IBS or FAP manifested a broad gastrointestinal symptom profile compared with healthy controls with large differences, indicating the critical need for more effective interventions to bring patient functioning within the range of healthy functioning.

Randomised clinical trial: gut microbiome biomarkers are associated with clinical response to a low FODMAP diet in children with the irritable bowel syndrome

BACKGROUND

A low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet can ameliorate symptoms in adult irritable bowel syndrome (IBS) within 48 h.

AIM

To determine the efficacy of a low FODMAP diet in childhood IBS and whether gut microbial composition and/or metabolic capacity are associated with its efficacy.

METHODS

In a double-blind, crossover trial, children with Rome III IBS completed a 1-week baseline period. They then were randomised to a low FODMAP diet or typical American childhood diet (TACD), followed by a 5-day washout period before crossing over to the other diet. GI symptoms were assessed with abdominal pain frequency being the primary outcome. Baseline gut microbial composition (16S rRNA sequencing) and metabolic capacity (PICRUSt) were determined. Metagenomic biomarker discovery (LEfSe) compared Responders (≥50% decrease in abdominal pain frequency on low FODMAP diet only) vs. Nonresponders (no improvement during either intervention).

RESULTS

Thirty-three children completed the study. Less abdominal pain occurred during the low FODMAP diet vs. TACD [1.1 ± 0.2 (SEM) episodes/day vs. 1.7 ± 0.4, P < 0.05]. Compared to baseline (1.4 ± 0.2), children had fewer daily abdominal pain episodes during the low FODMAP diet (P < 0.01) but more episodes during the TACD (P < 0.01). Responders were enriched at baseline in taxa with known greater saccharolytic metabolic capacity (e.g. Bacteroides, Ruminococcaceae, Faecalibacterium prausnitzii) and three Kyoto Encyclopedia of Genes and Genomes orthologues, of which two relate to carbohydrate metabolism.

CONCLUSIONS

In childhood IBS, a low FODMAP diet decreases abdominal pain frequency. Gut microbiome biomarkers may be associated with low FODMAP diet efficacy. ClinicalTrials.gov identifier: NCT01339117.

IBS and FAPS in children: a comparison of psychological and clinical characteristics

OBJECTIVES

It has been suggested that different subcategories of childhood abdominal pain-related functional gastrointestinal disorders (AP-FGIDs) are not separate clinical entities, but represent variable expressions of the same FGID. The aim of the present study was to compare clinical and psychological characteristics of children with irritable bowel syndrome (IBS), functional abdominal pain (FAP), and functional abdominal pain syndrome (FAPS).

METHODS

A total of 259 children, ages 8 to 18 years, fulfilling Rome III criteria for IBS or FAPS were included in a randomized controlled trial evaluating the effect of hypnotherapy. At inclusion, questionnaires assessed demographics, clinical features, abdominal pain frequency and intensity, depression and anxiety, somatization, health-related quality of life, pain beliefs, and coping strategies.

RESULTS

No differences were found between children with IBS and those with FAPS with respect to the main outcomes: frequency and intensity of abdominal pain, symptoms of depression and anxiety, somatization, health-related quality of life, pain beliefs, and coping strategies. A significantly higher percentage of patients with IBS had a positive family history for AP-FGIDs (56.8% vs 37.8%; P = 0.00). Characteristics of patients with IBS subtypes did not differ. Patients with FAP or FAPS differed only with respect to problem-focused coping strategy (2.21 ± 0.61 vs 2.52 ± 0.49; P = 0.00).

CONCLUSIONS

Pediatric patients with IBS and those with FAPS have similar psychosocial profiles. These results may explain why treatment response of psychological therapies in these AP-FGIDs is similar. These results may indicate that pediatric IBS and FAPS are different expressions of 1 underlying functional disorder, but similarities in psychosocial characteristics do not exclude the possibility that these disorders are different entities, because these similarities can exist between disorders of various causes. Therefore, future research is required on the role of other (physiological) factors in pediatric IBS and FAPS.