Preschoolers With Allergic Diseases Have an Increased Risk of Irritable Bowel Syndrome When Reaching School Age

Postprandial symptoms in disorders of gut-brain interaction and their potential as a treatment target

Postprandial, or meal-related, symptoms, such as abdominal pain, early satiation, fullness or bloating, are often reported by patients with disorders of gut-brain interaction, including functional dyspepsia (FD) or irritable bowel syndrome (IBS). We propose that postprandial symptoms arise via a distinct pathophysiological process. A physiological or psychological insult, for example, acute enteric infection, leads to loss of tolerance to a previously tolerated oral food antigen. This enables interaction of both the microbiota and the food antigen itself with the immune system, causing a localised immunological response, with activation of eosinophils and mast cells, and release of inflammatory mediators, including histamine and cytokines. These have more widespread systemic effects, including triggering nociceptive nerves and altering mood. Dietary interventions, including a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols, elimination of potential food antigens or gluten, IgG food sensitivity diets or salicylate restriction may benefit some patients with IBS or FD. This could be because the restriction of these foods or dietary components modulates this pathophysiological process. Similarly, drugs including proton pump inhibitors, histamine-receptor antagonists, mast cell stabilisers or even tricyclic or tetracyclic antidepressants, which have anti-histaminergic actions, all of which are potential treatments for FD and IBS, act on one or more of these mechanisms. It seems unlikely that food antigens driving intestinal immune activation are the entire explanation for postprandial symptoms in FD and IBS. In others, fermentation of intestinal carbohydrates, with gas release altering reflex responses, adverse reactions to food chemicals, central mechanisms or nocebo effects may dominate. However, if the concept that postprandial symptoms arise from food antigens driving an immune response in the gastrointestinal tract in a subset of patients is correct, it is paradigm-shifting, because if the choice of treatment were based on one or more of these therapeutic targets, patient outcomes may be improved.

Multimorbidity of Allergic Diseases Is Associated With Functional Gastrointestinal Disorders in a Young Japanese Population

Background/Aims

Although certain allergic diseases have been reported to be associated with the prevalence of functional dyspepsia (FD) and irritable bowel syndrome (IBS), it is unclear whether the presence of multiple allergic diseases further increases the prevalence of FD and IBS. The aim of this study is to determine this issue in young people.

Methods

A cohort of 8923 Japanese university students was enrolled and diagnoses of FD and IBS were confirmed using Rome III criteria. Allergic disorders diagnosed at medical institutions were obtained by means of a self-administered questionnaire.

Results

The prevalence of FD, IBS, and their overlap was found to be 1.9%, 6.5%, and 1.1%, respectively. Pollen allergy was independently positively correlated with FD, IBS, and overlap of FD and IBS. Allergic rhinitis was positively linked to IBS. Drug allergy was positively associated with FD. The presence of multiple allergic diseases was positively correlated with FD and IBS (FD: adjusted OR for 2 allergic diseases: 1.95 [95% CI, 1.24-2.98], P for trend = 0.003; and IBS: adjusted OR for 1 allergic disease: 1.40 [95% CI, 1.15-1.69], 2 allergic diseases 1.47 [95% CI, 1.12-1.91], and 3 or more allergic diseases: 2.22 [95% CI, 1.45-3.28], P for trend = 0.001). Additionally, the concomitant existence of multiple allergic diseases was also demonstrated to have a trend that correlated with the overlap of FD and IBS (P for trend = 0.018).

Conclusion

Allergic disease multimorbidity is positively correlated with the prevalence of FD and IBS in a young population.

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.

An ESPGHAN Position Paper on the Diagnosis, Management, and Prevention of Cow's Milk Allergy

A previous guideline on cow's milk allergy (CMA) developed by the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) was published in 2012. This position paper provides an update on the diagnosis, treatment, and prevention of CMA with focus on gastrointestinal manifestations. All systematic reviews and meta-analyses regarding prevalence, pathophysiology, symptoms, and diagnosis of CMA published after the previous ESPGHAN document were considered. Medline was searched from inception until May 2022 for topics that were not covered in the previous document. After reaching consensus on the manuscript, statements were formulated and voted on each of them with a score between 0 and 9. A score of ≥6 was arbitrarily considered as agreement. Available evidence on the role of dietary practice in the prevention, diagnosis, and management of CMA was updated and recommendations formulated. CMA in exclusively breastfed infants exists, but is uncommon and suffers from over-diagnosis. CMA is also over-diagnosed in formula and mixed fed infants. Changes in stool characteristics, feeding aversion, or occasional spots of blood in stool are common and in general should not be considered as diagnostic of CMA, irrespective of preceding consumption of cow's milk. Over-diagnosis of CMA occurs much more frequently than under-diagnosis; both have potentially harmful consequences. Therefore, the necessity of a challenge test after a short diagnostic elimination diet of 2-4 weeks is recommended as the cornerstone of the diagnosis. This position paper contains sections on nutrition, growth, cost, and quality of life.

Role of inflammation in pediatric irritable bowel syndrome

BACKGROUND

IBS affects a large number of children throughout the world and is thought to be the result of disturbed neuroimmune function along with the brain-gut axis. Although the underlying pathophysiologic mechanisms are not clear, the role of low-grade inflammation and mucosal immune activation in IBS symptom generation has become evident also in subsets of pediatric patients. Animal models provided meaningful insight in the causal relationship between abnormal mucosal immune activation and changes in gastrointestinal (GI) sensory-motor function. Likewise, the development of long-standing GI symptoms fulfilling the current criteria for functional GI disorders after infection gastroenteritis and in patients with IBD or celiac disease in remission further supports this hypothesis. Immune activation, its impact on gut sensory-motor function, and potential implications for symptom generation emerged in both children and adults with IBS.

PURPOSE

The aim of this review is to summarize the main evidence on the presence of low-grade inflammation and immune activation in children with IBS, its possible role in symptom generation, and its potential implication for new therapeutic strategies.

Infantile Colic and the Subsequent Development of the Irritable Bowel Syndrome

Background/Aims

Little is known about the association between infantile colic and the later onset of irritable bowel syndrome (IBS).

Methods

This study examined all 917 707 children who were born in Korea between 2007 and 2008. Infantile colic was defined with 1 or more diagnoses of ICD-10 code R10.4 or R68.1 at the age of 5 weeks to 4 months, and infants with a diagnosis of infantile colic and without were allocated into the infantile colic group and the control group. IBS was defined as 2 or more diagnoses of ICD-10 code K58.X after 4 years of age. Each child was traced until 2017. The risk of IBS with infantile colic was evaluated using a Cox proportional hazards model with propensity score inverse probability of treatment weighting (IPTW).

Results

After IPTW, 363 528 and 359 842 children were allocated to the control group and the infantile colic group, respectively. The infantile colic group had a higher risk of developing IBS in childhood (hazard ratio [95% CI], 1.12 [1.10 to 1.13]) than the control group. Moreover, the subgroup analyses according to the feeding status, birth weight, sex, or economic status, showed that the risk of IBS with former infantile colic remained statistically significant.

Conclusions

Children with a diagnosis of infantile colic during the infant period had a significant risk of developing IBS after 4 years of age. Understanding the pathogenesis of infantile colic in the neonatal period may reduce the prevalence and severity of functional gastrointestinal disorders from childhood to adolescence to adulthood.

Cows' Milk Allergy-Associated Constipation: When to Look for It? A Narrative Review

Constipation is a very common disorder, mostly functional in nature, that may persist for years in up to 35-52% of children. Food allergy prevalence, severity and persistence are increasing over time, and cows' milk protein is the commonest food allergen recognised to affect gastrointestinal motility in children. There is mounting evidence of the role of cows' milk (CM) allergy (CMA) in children with constipation. With this narrative review, we aim to provide clinicians with an updated and critical overview of food allergy-associated constipation. We searched Embase, Medline and the Cochrane Library, using keywords related to the topic. Only reviews and studies including children aged 0-17 years that were published in English were considered. Constipation has been reported in 4.6% of infants with CMA; the prevalence of food allergy underlying chronic constipation in children resistant to conventional treatment and presenting to tertiary clinics ranges between 28% and 78%. The identification of predisposing risk factors and of a specific phenotype of food allergy-induced constipation remains elusive. No allergic tests, radiological or motility investigations achieve sufficient sensitivity and specificity to screen children for CMA-related constipation. A 4-week cows' milk protein (CMP) elimination diet may be considered for children with chronic constipation resistant to conventional treatment and who lack alarm sign/symptoms of organic diseases. In subjects with ameliorated symptoms on CMP elimination, the diagnosis of CMA should be confirmed by a food challenge to avoid an unnecessary protracted diet.

Association of Consuming Tap Water or Purified Water during Infancy with Irritable Bowel Syndrome in Children

Objective: The objective of this study was to analyze the effect of consuming formula powder prepared with tap water or purified water during the first 4 to 6 months of life on the subsequent development of irritable bowel syndrome (IBS). Study design and setting: A total of 917,707 children who were born in Korea between 2007 and 2008 were analyzed. All children were followed up until they lost eligibility for health care services or until 2017. Data on the water used to prepare formula powder were from questionnaires answered by the parents when the child was 4 to 6 months old. IBS was defined as two or more diagnoses of IBS after the age of 4 years. Inverse probability of treatment weighting (IPTW) using the propensity score was used to balance the two groups. The risk of IBS was evaluated using a Cox proportional hazards model. Results: After weighting, there were 73,355 children in the tap water group and 73,351 in the purified water group. The purified water group had a higher risk of IBS (HR: 1.05; 95% CI: 1.01, 1.09). This relationship was also present after the subgroup analyses of males and females and the sensitivity analysis that used different definitions of IBS. Conclusions: Drinking formula powder prepared with purified water rather than tap water during the first 4 to 6 months of age was found to be associated with IBS.

Colonic Mucosal Immune Activation in Mice with Ovalbumin-Induced Allergic Airway Disease: Association between Allergic Airway Disease and Irritable Bowel Syndrome

Recent studies on the pathophysiology of irritable bowel syndrome (IBS) have focused on the role of mast cells (MCs) in intestinal mucosal immunity. A link between allergic airway diseases (AADs) and IBS has been suggested because both diseases have similar pathophysiology. We aimed to investigate whether the induction of AAD in mice could lead to inflammation of the colonic mucosa, similar to IBS. We also evaluated whether this inflammatory response could be suppressed by administering a therapeutic agent. Mice were divided into three groups: control, AAD-induced, and salbutamol-treated. An AAD mouse model was established by intraperitoneal injection and nasal challenge with ovalbumin. Mice with AAD were intranasally administered salbutamol. Analyses of cytokine levels, MC count, and tryptase levels in the intestinal mucosa were performed to compare the changes in inflammatory responses among the three groups. Inflammation was observed in the intestinal mucosa of mice in the AAD group. This inflammation in AAD mice was suppressed after salbutamol treatment. Our study demonstrates that AAD induces an inflammatory response similar to that in IBS, suggesting a possible association between IBS and AADs. In patients with IBS with such allergic components, salbutamol may have the potential to alleviate the inflammatory response.

Allergy-related diseases in childhood and risk for abdominal pain-related functional gastrointestinal disorders at 16 years-a birth cohort study

BACKGROUND

Studies on allergy-related diseases in relation to abdominal pain-related functional gastrointestinal disorders (AP-FGIDs) in children are few and results are contradictory. We examined the associations between childhood allergy-related diseases and adolescent AP-FGIDs in general and irritable bowel syndrome (IBS) in particular.

METHOD

Prospective population-based birth cohort study of 4089 children born in Sweden 1994-1996. We analysed data from 2949 children with complete follow-up at 16 years (y) and no diagnosis of inflammatory bowel disease or coeliac disease at 12y or 16y. Asthma, rhinitis, eczema, and food hypersensitivity (FH) were assessed through questionnaires at 1-2y, 4y, 8y, 12y, and 16y. AP-FGIDs and IBS were assessed through questionnaires at 16y and defined according to the Rome III criteria. Associations between childhood allergy-related diseases and any AP-FGID and IBS and 16y respectively were examined using binomial generalized linear models with a log link function and described as relative risk with 95% confidence intervals.

RESULTS

The prevalence of any AP-FGID and IBS at 16y were 12.0% and 6.0% respectively. Eczema at 1-2y, 4y, and 8y, and FH at 12y and 16y were associated with an increased risk for any AP-FGID at 16y. Asthma and FH at 12y and 16y were associated with an increased risk for IBS at 16y. The relative risk for IBS at 16y increased with increasing number of concurrent allergy-related diseases at 16y, but linear trend for relative risk was only borderline statistically significant (P for trend = 0.05).

CONCLUSIONS

This prospective population-based study demonstrated positive associations between childhood allergy-related diseases and adolescent AP-FGIDs, including IBS, implicating shared pathophysiology among these disorders.

Update on the Role of Allergy in Pediatric Functional Abdominal Pain Disorders: A Clinical Perspective

Both functional abdominal pain disorders (FAPDs) and food allergies are relatively common in children and adolescents, and most studies report an association between FAPDs and allergic conditions. FAPDs share pathophysiologic processes with allergies, including both immune and psychological processes interacting with the microbiome. No conclusive data are implicating IgE-mediated reactions to foods in FAPDs; however, there may be patients who have IgE reactions localized to the gastrointestinal mucosa without systemic symptoms that are not identified by common tests. In FAPDs, the data appears stronger for aeroallergens than for foods. It also remains possible that food antigens initiate an IgG reaction that promotes mast cell activation. If a food allergen is identified, the management involves eliminating the specific food from the diet. In the absence of systemic allergic symptoms or oral allergy syndrome, it appears unlikely that allergic triggers for FAPDs can be reliably identified by standard testing. Medications used to blunt allergic reactions or symptomatically treat allergic reactions may be useful in FAPDs. The purpose of the current manuscript is to review the current literature regarding the role of allergy in FAPDs from a clinical perspective, including how allergy may fit in the current model of FAPDs.

Parental, Perinatal, and Childhood Risk Factors for Development of Irritable Bowel Syndrome: A Systematic Review

Background/Aims

Adverse early life experiences are associated with the development of stroke, cancer, diabetes, and chronic respiratory and ischemic heart diseases. These negative experiences may also play a role in the development of irritable bowel syndrome (IBS)--a functional gastrointestinal disease. This review discusses the research to date on the parental, perinatal, and childhood risk and protective factors associated with the development of IBS.

Methods

A literature search was completed for studies published between 1966 and 2018 that investigated premorbid factors occurring during the perinatal and childhood periods as well as parental factors that were associated with the development of IBS.

Results

Twenty-seven studies fulfilled the review criteria. Risk factors that appeared in more than one study included: (1) parental IBS, substance abuse, parental punishment, and rejection as parental risk factors; (2) low birth weight as a perinatal risk factor; and (3) crowded living conditions in low-income families, childhood anxiety, depression, or child abuse as childhood risk factors. Protective factors for IBS were emotional warmth from the parents and being born to an older mother.

Conclusions

More effort is needed to identify what fetal and maternal factors are associated with low birth weight and IBS. A well-executed prospective birth cohort with a collection of bio-samples and functional data will provide a better understanding of how adversity and the interplay between genetics, epigenetics, and numerous risk factors affect the development of IBS.

Association between Irritable Bowel Syndrome and Allergic Diseases: To Make a Case for Aeroallergen

Irritable bowel syndrome (IBS) is a functional gastrointestinal disease and the most common cause of prolonged abdominal pain and bowel disturbances in the developed world. While initially thought to be functional or psychosomatic in nature, IBS is now recognized as a heterogeneous group of conditions. A subset of IBS patients and patients with allergic diseases share some characteristic inflammatory features. In fact, atopic children show an increased likelihood of developing IBS as adults. Given these findings, a subset of IBS may be suffering from allergy-related gut diseases. In this review, we present the allergy-related comorbidities of IBS, including genetic, environmental, and immunologic factors. We discuss studies demonstrating an increased sensitization of IBS patients to aeroallergens compared to food allergens. We then postulate potential pathophysiological mechanisms underlying both IBS and aeroallergens in the gut, followed by potential implications in the screening and treatment of allergies in IBS patients.

Dietary Treatment with Extensively Hydrolyzed Casein Formula Containing the Probiotic Lactobacillus rhamnosus GG Prevents the Occurrence of Functional Gastrointestinal Disorders in Children with Cow's Milk Allergy

OBJECTIVE

To investigate whether the addition of the probiotic Lactobacillus rhamnosus GG (LGG) to the extensively hydrolyzed casein formula (EHCF) for cow's milk allergy (CMA) treatment could reduce the occurrence of functional gastrointestinal disorders (FGIDs).

STUDY DESIGN

This cohort study included children with a positive history for CMA in the first year of life who were treated with EHCF alone or in combination with LGG and had evidence of immune tolerance acquisition to cow's milk for at least 12 months. FGID was diagnosed according to the Rome III diagnostic criteria by investigators unaware of previous treatment. A cohort of consecutive healthy children was also evaluated as a control population.

RESULTS

A total of 330 subjects were included, 110 per cohort (EHCF, EHCF+LGG, and healthy controls). The rate of subjects with ≥1 FGID was significantly lower in the EHCF+LGG cohort compared with the EHCF cohort (40% vs 16.4%; P < .05). In the EHCF+LGG cohort, a lower incidence was observed for all components of the main study outcome. The prevalence of FGIDs in the healthy cohort was lower than that in the EHCF cohort and similar to that in the EHCF+LGG cohort. The incidence rate ratio of FGIDs for the EHCF+LGG cohort vs the EHCF cohort (0.40; 95% CI, 0.25-0.65; P < .001) was unmodified after correction for age at CMA diagnosis, breastfeeding, weaning time, and presence of a first-degree relative with an FGID.

CONCLUSIONS

These results confirm the increased risk for developing FGIDs in children with CMA and suggest that EHCF+LGG could reduce this risk.

Is Long-term Ambient Air Pollutant Exposure a Risk Factor for Irritable Bowel Syndrome in Children? A 12-year Longitudinal Cohort Study

Background/Aims

Recent studies suggest that air pollution may play a role in gastrointestinal disorders. However, the effect of long-term exposure to air pollution on childhood irritable bowel syndrome (IBS) is unclear. Hence, we conducted a nationwide cohort study to investigate the association between long-term air pollution exposure and the incidence and risk of IBS in Taiwanese children during 2000-2012.

Methods

We collected data from the Taiwan National Health Insurance Research Database, linked to the Taiwan Air Quality-Monitoring Database according to the insurant living area and the air quality-monitoring station locations. Children < 18 years old, identified from January 1st, 2000, were followed-up until IBS diagnosis or December 31st, 2012. The daily average air pollutant concentrations were categorized into 4 quartile-based groups (Q1-Q4). We measured the incidence rate, hazard ratios (HRs), and 95% confidence intervals for IBS stratified by the quartiles of air pollutant concentration.

Results

A total of 3537 children (1.39%) were diagnosed with IBS within the cohort during the follow-up period. The incidence rate for IBS increased from 0.84 to 1.76, from 0.73 to 1.68, from 0.85 to 1.98, and from 0.52 to 3.22 per 1000 person-years, with increase in the carbon monoxide, nitrogen dioxide, non-methane hydrocarbon, and methane quartile (from Q1 to Q4) exposure concentration, respectively. The adjusted HR for IBS increased with elevated carbon monoxide, nitrogen dioxide, non-methane hydrocarbon, and methane exposure in Q4 to 1.98, 2.14, 2.19, and 5.87, respectively, compared with Q1.

Conclusion

Long-term ambient air pollutant exposure is an environmental risk factor for childhood IBS.

Cow's Milk Protein Allergy in Infancy: A Risk Factor for Functional Gastrointestinal Disorders in Children?

The role and prevalence of cow's milk protein allergy (CMA) in functional gastrointestinal disorders remains unclear. The aim of this review is to update knowledge on the relationship between CMA and functional abdominal pain disorders (FAPDs) in children. Cochrane Database and Pubmed were searched from inception using general and specific terms for CMA and functional gastrointestinal disorders. CMA is reported as a predisposing or coexisting factor in a wide range of functional gastrointestinal disorders in infants and children. Pathogenesis of both conditions is complex and multiple mechanisms including dysmotility and hypersensitivity might contribute to the clinical manifestations. Data supporting the possible role of food allergies in the pathogenesis of FAPDs are limited. CMA may predispose to early life inflammation and visceral hypersensitivity, which in turn might manifest as FAPDs. The diagnosis of either CMA or FAPDs and distinction between them is challenging because of nonspecific and overlapping symptoms. Lack of accurate allergy tests in non-IgE (immunoglobulin E) mediated cases is also problematic. Oral food challenge, following an elimination diet, should be performed to diagnose a suspected non-IgE CMA allergy in children with FAPDs. In the management of FAPDs, an elimination diet should be considered for a limited period to verify if the symptoms improve or resolve.

The "Biology-First" Hypothesis: Functional disorders may begin and end with biology-A scoping review

While it is generally accepted that gastrointestinal infections can cause functional disturbances in the upper and lower gastrointestinal tract-known as postinfectious irritable bowel syndrome (PI-IBS) and functional dyspepsia (PI-FD)-it has still not been widely recognized that such an infection can also initiate functional non-intestinal diseases, and that non-intestinal infections can provoke both intestinal and non-intestinal functional disturbances. We conducted a scoping review of the respective literature and-on the basis of these data-hypothesize that medically unexplained functional symptoms and syndromes following an infection may have a biological (genetic, endocrine, microbiological) origin, and that psychological and social factors, which may contribute to the disease "phenotype," are secondary to this biological cause. If this holds true, then the search for psychological and social theories and factors to explain why one patient develops a chronic functional disorder while another does not is-at least for postinfectious states-misleading and detracts from exploring and identifying the true origins of these essentially biological disorders. The biopsychosocial model may, as the term implies, always begin with biology, also for functional (somatoform) disorders.

Irritable bowel syndrome in children: Current knowledge, challenges and opportunities

Irritable bowel syndrome (IBS) is a common and troublesome disorder in children with an increasing prevalence noted during the past two decades. It has a significant effect on the lives of affected children and their families and poses a significant burden on healthcare systems. Standard symptom-based criteria for diagnosis of pediatric IBS have changed several times during the past two decades and there are some differences in interpreting symptoms between different cultures. This has posed a problem when using them to diagnose IBS in clinical practice. A number of potential patho-physiological mechanisms have been described, but so far the exact underlying etiology of IBS is unclear. A few potential therapeutic modalities have been tested in children and only a small number of them have shown some benefit. In addition, most of the described patho-physiological mechanisms and treatment options are based on adult studies. These have surfaced as challenges when dealing with pediatric IBS and they need to be overcome for effective management of children with IBS. Recently suggested top-down and bottom-up models help integrating reported patho-physiological mechanisms and will provide an opportunity for better understanding of the diseases process. Treatment trials targeting single treatment modalities are unlikely to have clinically meaningful therapeutic effects on IBS with multiple integrating patho-physiologies. Trials focusing on multiple combined pharmacological and non-pharmacological therapies are likely to yield more benefit. In addition to treatment, in the future, attention should be paid for possible prevention strategies for IBS.

Allergic Proctocolitis Is a Risk Factor for Functional Gastrointestinal Disorders in Children

OBJECTIVE

To test the hypothesis that allergic proctocolitis, a cause of self-limiting rectal bleeding in infants, can predispose to the development of functional gastrointestinal disorders (FGIDs) later in childhood.

STUDY DESIGN

We studied a cohort of 80 consecutive patients diagnosed with allergic proctocolitis. Their sibling or matched children presenting to the same hospital for minor trauma served as controls. Parents of the patients with allergic proctocolitis and controls participated in a telephone interview every 12 months until the child was at least 4 years old. At that time, they were asked to complete the parental Questionnaire on Pediatric Gastrointestinal Symptoms, Rome III version.

RESULTS

Sixteen of the 160 subjects (10.0%) included in the study met the Rome III criteria for FGIDs. Among the 80 patients with allergic proctocolitis, 12 (15.0%) reported FGIDs, compared with 4 of 80 (5.0%) controls (P = .035). After adjustment for age and sex, the OR for FGIDs in allergic proctocolitis group was 4.39 (95% CI, 1.03-18.68). FGIDs were significantly associated with iron deficiency anemia, duration of hematochezia, and younger age at presentation. In a multivariate analysis, only the duration of hematochezia was significantly associated with the development of FGIDs (OR, 3.14; 95% CI,1.72-5.74).

CONCLUSIONS

We have identified allergic proctocolitis as a new risk factor for the development of FGIDs in children. Our data suggest that not only infection, but also a transient early-life allergic inflammatory trigger may induce persistent digestive symptoms, supporting the existence of "postinflammatory" FGIDs.

A 8-year population-based cohort study of irritable bowel syndrome in childhood with history of atopic dermatitis

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder affecting a large number of people worldwide. Based on the concept of central sensitization, we conducted a population-based cohort analysis to investigate the risk of IBS in children with atopic dermatitis (AD) as one of the first steps in the atopic march. From 2000 to 2007, 1 20 014 children with newly diagnosed AD and 1 20 014 randomly selected non-AD controls were included in the study. By the end of 2008, incidences of IBS in both cohorts and the AD cohort to non-AD cohort hazard ratios (HRs) and CIs were measured. The incidence of IBS during the study period was 1.45-fold greater (95% CI: 1.32 to 1.59) in the AD cohort than in the non-AD cohort (18.8 vs 12.9 per 10 000 person-years). The AD to non-AD HR of IBS was greater for girls (1.60, 95% CI: 1.39 to 1.85) and children≥12 years (1.59, 95% CI: 1.23 to 2.05). The HR of IBS in AD children increased from 0.84 (95% CI: 0.75 to 0.94) for those with ≤3 AD related visits to 16.7 (95% CI: 14.7 to 18.9) for those with >5 visits (P<0.0001, by the trend test). AD children had a greater risk of developing IBS. Further research is needed to clarify the role of allergy in the pathogenesis of IBS.