Saito, Yuri A.

SummaryBackgroundRumination syndrome is a functional gastroduodenal disorder characterised by effortless regurgitation of recently ingested food. Emerging evidence reports duodenal eosinophilic inflammation in a subset, suggesting a shared pathophysiology with functional dyspepsia (FD).AimTo assess the clinical features of rumination syndrome and FD in a community‐based study.MethodsWe mailed a survey assessing gastrointestinal symptoms, diet and psychological symptoms to 9835 residents of Olmsted County, MN, USA in 2017‐2018; diagnostic codes were obtained from linked clinical records. The two disorders were assessed as mutually exclusive in ‘pure’ forms with a separate overlap group, all compared to a control group not meeting criteria for either. Prevalence of associations, and univariate and independent associations with predictors were assessed by logistic regression.ResultsPrevalence of rumination syndrome and FD were 5.8% and 7.1%, respectively; the overlap was 3.83‐times more likely than expected by chance. Independent predictors for rumination (odds ratio (OR), 95% confidence interval (CI)) were female gender (1.79, 1.21‐2.63), smoking (1.89, 1.28‐2.78), gluten‐free diet (1.58, 1.14‐2.19), allergic rhinitis (1.45, 1.01‐2.08) and depression (1.10, 1.05‐1.16). FD was independently associated with female gender, depression, non‐coeliac wheat sensitivity, migraine, irritable bowel syndrome and somatic symptoms. A similar reported efficacy (≥54%) of low fat or dairy‐free diets was found with both disorders (P = 0.53 andP = 1.00, respectively). The strongest independent associations with overlapping FD and rumination syndrome were a history of rheumatoid arthritis (3.93, 1.28‐12.06) and asthma (3.02, 1.44‐6.34).ConclusionRumination syndrome overlaps with FD with a shared risk factor profile, suggesting a common pathophysiology.

Summary Background Pregabalin is a calcium channel α2δ ligand that modifies visceral hypersensitivity in IBS patients. Clinical data for pregabalin in IBS are lacking. Aim To test the efficacy of pregabalin on gastrointestinal symptoms in IBS patients. Methods A double‐blind, placebo‐controlled trial was performed. Adults meeting IBS Rome III criteria with ≥3 pain attacks per month were randomised to pregabalin 225 mg vs placebo twice daily for 12 weeks. Questionnaires were completed weekly. The primary endpoint was average pain Bowel Symptom Scale (BSS) scores weeks 9‐12. An intention‐to‐treat analysis of covariance evaluated treatment effects on quantitative endpoints, adjusting for age and gender. Adequate relief and change in pain score were assessed using a chi‐squared test. Results Eighty‐five patients were recruited and randomised. Sample characteristics include: mean age 39.4 (SD = 14.6); 73 (86%) female; 37 (44%) IBS‐D, 29 (35%) IBS‐M, 18 (21%) IBS‐C. The pregabalin arm had lower average pain‐BSS scores weeks 9‐12 (25 vs 42, P = 0.008). Compared with placebo, the overall IBS BSS severity score was lower in the pregabalin arm (26 vs 42, P = 0.009). Differences were observed for the diarrhoea‐BSS and bloating‐BSS scores ( P = 0.049 and 0.016, respectively). No differences between groups were seen for constipation‐BSS scores. Adequate relief was not different between the two arms (46% vs 36%, P = 0.35). 63% pregabalin vs 45% placebo had a change in pain score ≥30 at week 12 from baseline ( P = 0.10). Post‐treatment IBS‐QoL scores did not differ between groups. Conclusion This trial suggests that pregabalin may be beneficial for IBS abdominal pain, bloating and diarrhoea.

Goals: To evaluate agreement of MCM6-13910 with self-report of dairy sensitivity (DS) and lactose hydrogen methane breath test (LHMBT) results in subjects with irritable bowel syndrome (IBS). Background: IBS is a functional gastrointestinal disorder with symptoms including abdominal pain, variable bowel habits, and bloating. Adult patients with lactose malabsorption may present with similar symptoms. Patients with lactose malabsorption have a lactase nonpersistent (LNP) phenotype. Recent studies found 2 single nucleotide polymorphisms associated with LNP: G/A-22018 and C/T-13910. Study: Genotyping the MCM6-13910 variant of LNP in 538 IBS patients and 317 controls (without IBS). Subjects completed questionnaires pertaining to gastrointestinal problems and dietary consumption, with charts abstracted. Results: Self-reported DS was higher in IBS (45%) than controls (9.8%, odds ratio=6.46, P<0.001). The C/C-13910 genotype was similar in IBS cases and controls, 81 (15.1%) and 47 (14.8%). Among subjects reporting DS, 49 (18.0%) had the C/C genotype. Overall agreement between genotype and self-reported DS was 0.06 in IBS and 0.07 in controls. There were 20 subjects with LHMBT results; 3 had positive results, 17 were negative. LNP genotypes were found in all 3 of positive LHMBT results; 16 had negative LHMBT among the 17 who were lactase persistent. Agreement between C/C-13910 genotype and LHMBT was excellent with κ-statistic of 0.83 (0.50-1.00). Conclusions: In IBS patients, self-report of lactose intolerance are highly prevalent but are a poor indicator of underlying C/C-13910 genotype. LHMBT had excellent agreement with C/C-13910 genotype.

AbstractBackgroundIrritable bowel syndrome (IBS) is a common functional gastrointestinal disorder, diagnosed on symptom‐based criteria. Many have reported discrepancies between formal Rome criteria and diagnoses made in clinical practice. The aim of the study was to explore whether a quantitative version of the Rome criteria would better represent a clinical diagnosis of IBS than the current dichotomous criteria for symptom measure.MethodsAs part of a large, case‐control study, participants completed a validated bowel disease questionnaire. Rome criteria were analyzed based on 15 individual symptoms. Penalized logistic regression model with stepwise selection was used to identify significant symptoms of IBS which were independently associated with case‐control status.Key ResultsIn cases with a clinical diagnosis of IBS, 347 (70%) met Rome criteria for IBS. Increasing number of Rome symptoms were found related to the odds of being diagnosed with IBS. Nearly half of the Rome‐negative case group experienced infrequent symptoms suggesting milder disease. Five of 15 Rome symptoms were associated with predicting case‐control status in the final model, with 96% correctly classified among Rome‐positive cases, 76% for Rome‐negative cases, and 91% for controls.Conclusions and InferencesIrritable bowel syndrome appears to be a spectrum disorder. Quantifying individual symptoms of Rome criteria has greater utility than the current application in representing the degree of IBS affectedness and appears to better reflect a clinical diagnosis of IBS applied by physicians. The use of a quantitative diagnostic Rome “score” may be helpful in clinical practice and research studies to better reflect the degree an individual is affected with IBS.

Background and aimsRoutine serologic testing for celiac disease (CD) may be useful in irritable bowel syndrome (IBS) patients, but this is controversial. We aimed to compare the prevalence of unrecognized CD in a large cohort of patients with and without IBS.Participants and methodsThis is a family case–control IBS study conducted at a single US academic medical center. Stored serum and DNA were available. Tissue transglutaminase (TTg) immunoglobulin A was performed, followed by indirect immunofluorescence testing for endomysial antibodies with positive or weakly positive TTg results. Individuals were considered to have CD if both results were positive.χ2and Fisher’s exact tests were used to compare prevalence between the two groups.ResultsSerum samples were studied from 533 cases and 531 controls. In all, 80% of participants were female, with a median age of 50 years; 65% of cases and 0% controls met the Rome criteria for IBS. Previous serological testing for CD had occurred in 142 (27%) cases and 13 (2%) controls, but none had CD on subsequent testing. Six (1.1%) cases versus five (0.9%) controls had positive or weakly positive TTg test. Six cases (1.1%) versus three (0.6%) controls were confirmed to have CD by endomysial antibody (P=0.51).ConclusionNo difference in the prevalence of CD between patients with IBS and patients without IBS at a tertiary medical center was observed. Our findings do not support routine celiac serologic or genetic testing in patients with IBS in all US populations.

Linked ContentThis article is linked to Yiannakou et al paper. To view this article visit https://doi.org/10.1111/apt.14349.

The SCN5A-encoded voltage-gated mechanosensitive Na+channel NaV1.5 is expressed in human gastrointestinal smooth muscle cells and interstitial cells of Cajal. NaV1.5 contributes to smooth muscle electrical slow waves and mechanical sensitivity. In predominantly Caucasian irritable bowel syndrome (IBS) patient cohorts, 2–3% of patients have SCN5A missense mutations that alter NaV1.5 function and may contribute to IBS pathophysiology. In this study we examined a racially and ethnically diverse cohort of IBS patients for SCN5A missense mutations, compared them with IBS-negative controls, and determined the resulting NaV1.5 voltage-dependent and mechanosensitive properties. All SCN5A exons were sequenced from somatic DNA of 252 Rome III IBS patients with diverse ethnic and racial backgrounds. Missense mutations were introduced into wild-type SCN5A by site-directed mutagenesis and cotransfected with green fluorescent protein into HEK-293 cells. NaV1.5 voltage-dependent and mechanosensitive functions were studied by whole cell electrophysiology with and without shear force. Five of 252 (2.0%) IBS patients had six rare SCN5A mutations that were absent in 377 IBS-negative controls. Six of six (100%) IBS-associated NaV1.5 mutations had voltage-dependent gating abnormalities [current density reduction (R225W, R433C, R986Q, and F1293S) and altered voltage dependence (R225W, R433C, R986Q, G1037V, and F1293S)], and at least one kinetic parameter was altered in all mutations. Four of six (67%) IBS-associated SCN5A mutations (R225W, R433C, R986Q, and F1293S) resulted in altered NaV1.5 mechanosensitivity. In this racially and ethnically diverse cohort of IBS patients, we show that 2% of IBS patients harbor SCN5A mutations that are absent in IBS-negative controls and result in NaV1.5 channels with abnormal voltage-dependent and mechanosensitive function.NEW & NOTEWORTHY The voltage-gated Na+channel NaV1.5 contributes to smooth muscle physiology and electrical slow waves. In a racially and ethnically mixed irritable bowel syndrome cohort, 2% had mutations in the NaV1.5 gene SCN5A. These mutations were absent in irritable bowel syndrome-negative controls. Most mutant NaV1.5 channels were loss of function in voltage dependence or mechanosensitivity.

Goals: The goal of this study is to evaluate the association between early life infections and subsequent adult onset irritable bowel syndrome (IBS). Background: Infections during adulthood are a known risk factor for adult-onset IBS. This investigation examined the role of childhood infections and infection risk factors in the development of IBS symptoms. Study: In total, 1010 subjects (509 outpatients with IBS, 501 matched controls) were mailed questionnaires regarding early-life infections during infancy (0 to 12 mo), toddler years (1 to 3 y), and child years (4 to 18 y). Comparisons between cases and controls were performed using logistic regression adjusting for age, gender, and somatization score. Results: Around 648 (64.2%) subjects responded. The median age was 51.3 years (range, 18.0 to 70.7 y) and 535 (83%) were female. Childhood (below 18 y) infections were common in cases and controls (98% vs. 98%; P=0.465), with no differences between cases and controls during infant, toddler, and child-age periods. For gastrointestinal infections experienced below 18 years, no differences were observed by infection type (bacterial, viral, or parasitic) or age group. Cases were more likely to report bronchitis by age 18 [43% vs. 25%; P=0.003; odds ratio, 1.73 (1.20-2.51)], but not other common infections. Regular antibiotic exposure was greater amongst cases (43%) than controls (30%) [P=0.09; odds ratio, 1.37 (0.96-1.96)]. The association between bronchitis and IBS case status remained significant after adjusting for antibiotic use (P=0.01). Conclusions: Greater early childhood gastrointestinal infections rates were not observed in adult individuals with IBS compared with adult controls. The study does not support a statistically significant link between early life infections and IBS aside from bronchitis.