Asian motility studies in irritable bowel syndrome

Stimulus-Response Plots as a Novel Bowel-Sound-Based Method for Evaluating Motor Response to Drinking in Healthy People

Constipation is a common gastrointestinal disorder that impairs quality of life. Evaluating bowel motility via traditional methods, such as MRI and radiography, is expensive and inconvenient. Bowel sound (BS) analysis has been proposed as an alternative, with BS-time-domain acoustic features (BSTDAFs) being effective for evaluating bowel motility via several food and drink consumption tests. However, the effect of BSTDAFs before drink consumption on those after drink consumption is yet to be investigated. This study used BS-based stimulus-response plots (BSSRPs) to investigate this effect on 20 participants who underwent drinking tests. A strong negative correlation was observed between the number of BSs per minute before carbonated water consumption and the ratio of that before and after carbonated water consumption. However, a similar trend was not observed when the participants drank cold water. These findings suggest that when carbonated water is drunk, bowel motility before ingestion affects motor response to ingestion. This study provides a non-invasive BS-based approach for evaluating motor response to food and drink, offering a new research window for investigators in this field.

Evaluation of gallbladder contractility and Doppler findings in patients with irritable bowel syndrome; a case-control study

BACKGROUND

Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder causing abdominal pain, altered bowel habits and bloating without structural issues. Gallbladder dysfunction may be linked to IBS due to disrupted cholecystokinin release. This study aims to assess gallbladder function and related hemodynamic parameters using Doppler ultrasound in IBS before and after meals.

METHOD

In this case-control study, we investigated gallbladder function differences between constipation-predominant IBS (C-IBS) patients and healthy volunteers. Participants underwent ultrasonography to measure gallbladder parameters before and after consuming a predefined meal. Gallbladder volume, wall thickness and resistance index (RI) of cystic and superior mesenteric arteries (SMA) were assessed. Student t-test and paired t-test were used to compare case and control groups and pre- and post-meal data, respectively.

RESULTS

A total of 34 people (18 C-IBS and 16 healthy control) were included. The mean (Standard deviation) of gallbladder fasting volume was measured 24.74 (8.85) and 29.73 (9.65) cubic millimeter for case and controls, respectively. Postprandial volume was 11.34 (5.66) and 16.9 (6.16) cubic millimeter for case and controls respectively. We observed a statistically significant difference in emptying fractions (EF) between groups (p value = 0.009). IBS patients had a smaller fasting SMA RI (p value = 0.016) but the fraction of change after meal was not significant (p value = 0.10). The cystic artery RI did not reach statistical significance between the fasting and post-meal values (p value = 0.067).

CONCLUSION

IBS patients have a higher emptying fraction and lower change in SMA RI compared to healthy controls. Further studies with larger sample size, inclusion of patients with different coexisting conditions and subtypes of IBS and combining colon transit study with gallbladder ejection fraction evaluation can be used to further provide more meaning to this study.

Update in diagnosis and management of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by a lack of structural or biochemical abnormalities. The current diagnosis of IBS is based on the Rome IV criteria, and it is recommended to approach IBS patients using a multidimensional clinical profile (MDCP). The pathophysiology of IBS is multifactorial and involves motility disorders, genetic factors, immune responses, visceral hypersensitivity, brain-gut dysregulation, and altered intestinal microbiota. The management of IBS includes both nonpharmacologic and pharmacologic therapies. Nonpharmacologic therapy options include physical activity, low fermentable oligosaccharides, disaccharides, monosaccharides, and polyol diet, as well as cognitive behavioral therapy. Pharmacologic therapy options include probiotics, antidepressants, antispasmodics, and new agents. In clinical practice, a multidisciplinary strategy, including nonpharmacologic or/and pharmacologic treatment for IBS, is emphasized. Therefore, clinicians should carefully consider the underlying pathophysiology before selecting an appropriate therapeutic option for the treatment of IBS. In other words, individualized treatment plans are necessary for managing IBS.

Children And Adolescents With Irritable Bowel Syndrome: Treatment And Management

BACKGROUND

Irritable bowel syndrome (IBS) is a disorder that causes stomach pain in children and adolescents. It may also impact one's quality of life. IBS is linked to gastrointestinal issues such as diarrhoea and constipation. Despite the identification of several potential pathophysiological pathways, the aetiology of IBS remained unknown.

OBJECTIVE

The aim of this paper is to discuss the diagnosis, pathogenesis, case studies and treatment of Irritable bowel syndrome in children and adolescents.

METHOD

This systematic review covered relevant papers from the previous ten years that were accessible in Science Direct, Elsevier, NCBI, and Web of Science related to the pathophysiology and function of pharmacological drugs such as antidepressants, antispasmodics, prokinetics, and antibiotics in children with irritable bowel syndrome.

RESULT

Only a few prospective therapy techniques have been investigated in children, and even fewer of those have been demonstrated to be effective. This article presents case studies including 50-59 children, which demonstrate a favourable acceptable impact that is more effective than a placebo in terms of reducing symptoms and improving the overall quality of life in children who have irritable bowel syndrome. Furthermore, the majority of the pathophysiological explanations and treatment options discussed are based on adult studies. These major issues arose when treating paediatric IBS, and they must be addressed in order to properly treat children with IBS. Trials that focus on many combinations of pharmacological and non-pharmacological therapies seem to be more helpful.

DISCUSSION

In recent years, a number of systematic reviews have been conducted to evaluate the efficacy of medication treatments in children for IBS; however, the dependability of these systematic reviews needs to be further investigated owing to the various experimental designs and levels of evidence used. This article highlights paediatric therapy options, including pharmaceutical medications such as antidepressants, antispasmodics, prokinetics, and antibiotics. The goal is to alleviate IBS symptoms while also enhancing the quality of life for children with this illness.

Probiotic therapy in patients with irritable bowel syndrome: does it have a real role?

Background

Irritable bowel syndrome (IBS) is one of the most prevalent functional gastrointestinal disorders (FGIDs). There is good evidence that microbiota plays a predominant role in the IBS pathophysiology. The aim of the study is to evaluate the role of probiotics in improvement of IBS symptoms via IBS-symptom severity scale (IBS-SSS Arabic version) and improvement of quality of life via irritable bowel syndrome-quality of life survey (IBS-QOL).

Results

This double-armed comparative trial was conducted on IBS patients, who fulfill ROME IV criteria and the IBS diagnostic questionnaire between August and December 2019. Ninety patients were followed up for 4 weeks from the first visit. The first group was prescribed probiotics (10 billion colony of Lactobacillus delbruekii and Lactobacillus fermentum) and itopride hcl 50 mg three times daily, while the second group received only itopride hcl 50 mg by the same dose for 4 weeks. There was a highly significant improvement in the IBS-SSS score in group 1 after 4 weeks of treatment than in group 2 (137.56±67.53 vs 258.44±34.18) (p=0.001). Also, there was a highly significant improvement in the overall QOL terms in group 1 in comparison with baseline QOL score [with overall mean score (60.64±7.77) at baseline vs (81.54±7.87) at 4 weeks (p value <0.001)].

Conclusion

Probiotics are useful for the improvement of IBS symptoms and quality of life of the studied patients. Larger multicenter studies are needed in the future.

Clinical Characteristics of Esophageal Motility Disorders in Patients With Heartburn

Background/Aims

Esophageal motility disorders (EMDs) contribute to the pathophysiology of gastroesophageal reflux disease. However, the causes of EMDs and their impact on gastroesophageal reflux disease-associated symptoms remain unknown. This study aims to elucidate clinical features associated with various types of EMDs in patients with heartburn symptoms.

Methods

Of the 511 patients who underwent high-resolution manometry, 394 who were evaluated for heartburn symptoms were examined. Patients subjected to high-resolution manometry were classified into 4 groups outflow obstruction group, hypermotility group, hypomotility group, and normal motility group. Symptoms were evaluated using 3 questionnaires. Patient characteristics and symptoms for each EMD type were compared with those of the normal motility group.

Results

Of the 394 patients, 193 (48.9%) were diagnosed with EMDs, including 71 with outflow obstruction, 15 with hypermotility, and 107 with hypomotility. The mean dysphagia score was significantly higher in each of the 3 EMD groups compared with those with normal motility. The mean acid reflux and dyspepsia scores were significantly lower in the outflow obstruction group (P < 0.05). The mean body mass index and median Brinkman index were significantly higher in the hypermotility group (P = 0.001 and P = 0.018, respectively), whereas the mean diarrhea and constipation scores were significantly lower in the hypomotility group (P < 0.05).

Conclusions

The results of our study indicate that different EMDs have distinct characteristics. Cigarette smoking and high body mass index were associated with esophageal hypermotility. Assessment of the dysphagia symptom scores may help identify patients with EMDs.

Association of heart rate variability, blood pressure variability, and baroreflex sensitivity with gastric motility at rest and during cold pressor test

AIM

To understand the mutual interaction of gastric motility and autonomic functions, the present study evaluated the association of heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS) with gastric motility assessed by electrogastrography (EGG) at rest and during CPT and explored the effect of sympathetic activation by cold pressor test (CPT) on gastric motility.

BACKGROUND

The autonomic nervous system has a significant influence on gastrointestinal motility. HRV is commonly employed to assess the functions of the autonomic nervous system. BPV and BRS are relatively newer techniques and give a more holistic picture of autonomic functions along with the short-term regulation of blood pressure (BP).

METHODS

In fourteen young, healthy subjects, gastric motility was assessed by EGG. Beat-to-beat BP and lead II ECG were recorded to assess HRV, BPV, and BRS. BPV and BRS parameters were calculated for systolic, mean, and diastolic BP. Parameters of HRV and BPV were calculated for time and frequency domains. BRS was calculated by sequence and spectral methods.

RESULTS

Significant increases in diastolic BP (p = <0.0001) and EGG frequency (p = 0.0229) were observed during CPT. Significant correlations were observed between EGG frequencies and many of the HRV, BPV, and BRS parameters. The correlation coefficient was found to be highest between total power of HRV and EGG frequencies during baseline (p = 0.0107, r = -0.6571) and during CPT (p = 0.0059, r = -0.6935).

CONCLUSION

EGG frequency can be decreased by an acute increase in sympathetic activity induced by CPT. The novel findings are the significant correlations between many of the HRV, BPV, and BRS parameters and EGG frequency.

Daily Short Message Service Reminders Increase Treatment Compliance and Efficacy in Outpatients with Functional Dyspepsia: a Prospective Randomized Controlled Trial

BACKGROUND

Many outpatients with functional dyspepsia (FD) do not follow the medication schedule recommendations, which can lead to illness relapse.

OBJECTIVE

To investigate whether short message service (SMS) reminders improve medication regimen adherence and therapeutic efficacy in outpatients with FD.

DESIGN

Participants with FD were randomly allocated to the control group or intervention group. Patients in the control group received a 4-week medication treatment with no reminders, those in the intervention group received medication treatment plus a daily SMS reminder of dose and medication time.

PARTICIPANTS

Newly diagnosed FD patients from April 2019 to June 2019 were recruited from the GI outpatient clinics at Renji Hospital.

MEASUREMENTS

The scores for FD symptoms (LDQ) and psychological conditions (PHQ-9 for depression and GAD-7 for anxiety) were assessed before and after the treatment. The medication possession ratio (MPR) was calculated.

KEY RESULTS

A total of 352 eligible patients was enrolled in the study. The overall compliance rates of patients in the intervention and control groups were 87.5% and 80.7% in the intention-to-treat (ITT) analysis (P = 0.08) and 94.48% and 86.59% in per-protocol (PP) analysis (P = 0.015), respectively. In the intervention group, the compliance rate of younger patients (age ≤ 40 years) was significantly higher than that of age-matched patients in the control group (ITT: 86.1% vs. 70.5%, P = 0.018). Compared with the control group, the reduction in scores of LDQ (9.33 vs. 8.02, P = 0.017), PHQ-9 (6.97 vs. 5.69, P = 0.004), and GAD-7 (8.70 vs.7.53, P = 0.028) was significantly greater in patients receiving SMS reminders. The MPR of patients positively correlated with the reduction in scores of LDQ, PHQ-9, and GAD-7 in both groups.

CONCLUSIONS

SMS reminders can improve treatment compliance and efficacy in patients with FD.

TRIAL REGISTRATION

NCT04052750.

Expression and clinical significance of 5-HT and 5-HT3R in the intestinal mucosa of patient with diarrhea-type irritable bowel syndrome

Expression levels and clinical significance of 5-HT and 5-HT₃R in the intestinal mucosa tissue of patients with diarrhea-type irritable bowel syndrome (D-IBS) were investigated. A retrospective analysis was performed on 46 tissue specimens (observation group) of the intestinal mucosa of patients with D-IBS, who were diagnosed in the Tongde Hospital of Zhejiang Province and received colonoscopy from March 2016 to December 2017, and 18 tissue specimens (control group) of the intestinal mucosa of healthy subjects who received physical examinations. The expression levels of 5-HT and 5-HT₃R in the intestinal mucosa tissue of patients in the observation and control group were detected by ELISA, and the relationship between 5-HT, 5-HT₃R and the clinicopathological parameters of patients with D-IBS was analyzed. Pearson's correlation analysis was used to analyze the correlation of 5-HT and 5-HT₃R in the intestinal mucosa tissue of patients with D-IBS. The expression levels of 5-HT and 5-HT₃R in the intestinal mucosa tissue of patients in the observation group were significantly higher than those of the patients in the control group (344.86±67.52 ng/ml and 13.04±8.34 pg/ml) (P<0.001). There was a positive correlation between the expression level of 5-HT and the expression level of 5-HT₃R in the intestinal mucosa tissue of patients with D-IBS (r=0.725, P<0.001). The expression levels of 5-HT and 5-HT₃R in the intestinal mucosa tissue of patients with D-IBS were both significantly higher than those of the healthy subjects. The expression levels of 5-HT and 5-HT₃R in patients with D-IBS were correlated with age, sex and the history of gastrointestinal infection. 5-HT and 5-HT₃R may be involved in the pathogenesis of D-IBS, and potentially used for clinical treatment.

Gut microbiota was modulated by moxibustion stimulation in rats with irritable bowel syndrome

Background

The pathogenesis of irritable bowel syndrome (IBS) is closely related to intestinal dysbacteriosis and can be controlled by moxibustion treatment. However, the mechanism underlying the therapeutic value of moxibustion in IBS treatment remains unknown.

Methods

An IBS rat model was established by colorectal distention (CRD) stimulus and mustard oil clyster. Sixty-five male rats were randomly divided into six groups: normal, IBS model, moxibustion, electroacupuncture (EA), Bifid-triple Viable Capsule (BTVC) and Pinaverium Bromide (PB) groups. The moxibustion group was treated with mild moxibustion at the bilateral Tianshu (ST25) and Shangjuxu (ST37) for 10 min/day for 7 days, the EA group was given EA at ST25 and ST37 once daily for 7 days, while the BTVC group and PB groups received Bifid-triple Viable Capsule and Pinaverium Bromide solution (at the proportion of 1:0.018) respectively by gavage once daily for 7 days. After the treatment, abdominal withdrawal reflex (AWR) scores were determined based on CRD stimulus, gut microbiota profiling was conducted by 16S rRNA high-throughput sequencing.

Results

Irritable bowel syndrome model rats had significantly increased AWR scores at all intensities (20, 40, 60 and 80 mmHg) compared with the normal group. Moxibustion treatment significantly reduced AWR scores compared with the IBS model group at all intensities. Across all groups the most abundant phyla were Bacteroidetes and Firmicutes followed by Proteobacteria and Candidatus Saccharibacteria. At genus level IBS model rats had a higher abundance of Prevotella, Bacteroides and Clostridium XI and a lower abundance of Lactobacillus and Clostridium XIVa compared with normal rats. These changes in microbiota profiles could however be reversed by moxibustion treatment. Alpha diversity was decreased in IBS model rats compared with normal rats, yet significantly increased in moxibustion- and PB-treated rats compared with IBS rats.

Conclusion

Our findings suggest that moxibustion treats IBS by modulating the gut microbiota.

Sex-Gender Differences in Irritable Bowel Syndrome

Because of the sex-gender differences that are shown in a diversity of physiological and psychological factors, it can be speculated that the clinical presentation of symptoms as well as treatment strategies in women and men with irritable bowel syndrome (IBS) may differ. Studies have revealed that IBS is more common in women than men. As for the IBS subtype, IBS with constipation is significantly more prevalent among women than men. Sex hormones and gender differences may play important roles in the pathophysiology of IBS. However, its pathophysiologic mechanisms still remain largely unknown, and therapeutic implications are limited. Moreover, women IBS patients have been reported to feel more fatigue, depression, anxiety, and lower quality of life than men IBS patients. Furthermore, there has been evidence of differences in the appropriate treatment efficacy to IBS in men and women, although relatively few men are enrolled in most relevant clinical trials. A more sex-gender-oriented approach in the medical care setting could improve understanding of heterogeneous patients suffering from IBS. An individualized and multicomponent approach including sex and gender issues might help improve the treatment of IBS.

Effects of Fengliao-Changweikang in Diarrhea-predominant Irritable Bowel Syndrome Rats and Its Mechanism Involving Colonic Motility

Background/Aims

This study was designed to investigate the effect of Fengliao-Changweikang (FLCWK) in diarrhea-predominant irritable bowel syndrome (IBS-D) rats and explore its underlying mechanisms.

Methods

IBS-D model rats were induced by neonatal maternal separation (NMS) combined with restraint stress (RS). In in vivo experiments, the model rats were randomly divided into 5 groups: NMS + RS, FLCWK (low dose, middle dose, and high dose), and pinaverium bromide. The normal control (no handling) rats were classified as the NH group. The therapeutic effect of FLCWK was evaluated by fecal characteristics, electromyographic response and abdominal withdrawal reflex scores. In in vitro experiments, the model rats were randomly divided into 2 groups: NMS + RS, FLCWK (middle dose), and no handling rats were used as the NH group. The differences in basic tension and ACh-induced tension of isolated colonic longitudinal smooth muscle strips (CLSMs) among the 3 groups were observed. In addition, different inhibitors (nifedipine, TMB-8, L-NAME, methylene blue, and 4-AP) were pretreated to explore the underlying mechanisms.

Results

In in vivo experiments, fecal characteristics, electromyographic response, and abdominal withdrawal reflex scores significantly improved in the FLCWK group, compared with the NMS + RS group. In in vitro experiments, the basic tension and ACh-induced tension of CLSMs in IBS-D rats were significantly inhibited by FLCWK. After pre-treatment with different inhibitors, the ACh-induced tension of CLSMs in each group showed no significant difference.

Conclusions

FLCWK manifested curative effect in IBS-D rats by inhibiting colonic contraction. The underlying mechanisms may be related to regulatory pathway of nitric oxide/cGMP/Ca²⁺ and specific potassium channels.

Role of Gut Microbiota-Gut Hormone Axis in the Pathophysiology of Functional Gastrointestinal Disorders

Gut microbiota exert a pivotal influence on various functions including gastrointestinal (GI) motility, metabolism, nutrition, immunity, and the neuroendocrine system in the host. These effects are mediated by not only short-chain fatty acids produced by microbiota but also gut hormones and inflammatory signaling by enteroendocrine and immune cells under the influence of the microbiota. GI motility is orchestrated by the enteric nervous system and hormonal networks, and disturbance of GI motility plays an important role in the pathophysiology of functional gastrointestinal disorders (FGIDs). In this context, microbiota-associated mediators are considered to act on specific receptors, thus affecting the enteric nervous system and, subsequently, GI motility. Thus, the pathophysiology of FGIDs is based on alterations of the gut microbiota/gut hormone axis, which have crucial effects on GI motility.

A double blind, placebo-controlled, randomized clinical trial that breast milk derived-Lactobacillus gasseri BNR17 mitigated diarrhea-dominant irritable bowel syndrome

The exact pathogenesis of diarrhea-dominant irritable bowel syndrome (IBS) is not known, but the abnormal microbiota of the gastrointestinal tract is considered to be one of the important contributing factors as in other gastrointestinal diseases such as inflammatory bowel disease, antibiotic-associated diarrhea, and colorectal cancer as well as systemic diseases. Though diverse trials of probiotics had been continued in the treatment of diarrhea-IBS, only a few proved by randomized clinical trial. To prove the efficacy of Lactobacillus gasseri BNR17 isolated from breast milk in patients with diarrhea-IBS, prospective, randomized, placebo controlled clinical trial was done including health related-quality of life analysis, colon transit time, and the changes of fecal microbiota. BNR17 significantly improved the symptoms of diarrhea compared to control group. Health related-QOL analysis showed significant improvement of abdominal pain, distension, disturbed daily life, and mean defecation frequency with BNR17. On comparative CTT before and after BNR17, 6 out of 24 subjects showed significant correction of rapid colon transit pattern, while only 2 out of 24 in placebo (p<0.01). Upon fecal microbiota analysis, BNR17 significantly increased B. fecalis, E. rectale, C. aerofaciens, F. prausnitzil and B. steroris. Conclusively, Lactobacillus gasseri BNR17 can be a potential probiotics to ameliorate diarrhea-IBS.

DA-9701 improves colonic transit time and symptoms in patients with functional constipation: A prospective study

BACKGROUND AND AIM

DA-9701, a newly developed prokinetic agent formulated with Pharbitis Semen and Corydalis Tuber, has been shown to effectively treat functional dyspepsia. Recently, it has also been suspected to improve gastrointestinal motor function. The aims of this study were to assess the effect of DA-9701 on colonic transit time (CTT) and symptoms of functional constipation.

METHODS

Thirty-three patients with functional constipation based on the Rome III criteria were prospectively enrolled. The patients received 30-mg DA-9701 three times a day for 24 days. CTT was estimated initially and at the end of treatment. Symptoms such as spontaneous bowel movements, straining, stool form, feeling of incomplete emptying and anorectal blockage, abdominal discomfort and pain, overall defecation satisfaction, and incidence of adverse events were also analyzed.

RESULTS

Twenty-seven patients completed the study. DA-9701 was associated with a significantly reduced CTT from 34.9 ± 17.6 to 23.7 ± 19.1 h (P = 0.001). Segmental CTT also significantly decreased after treatment (right CTT: from 16.8 [0.0-28.8] to 6.0 [0.0-25.2] hours, P < 0.001; rectosigmoid transit time: from 13.2 [0.0-38.4] to 6.0 [0.0-33.6] hours, P = 0.021). In addition, all constipation-related subjective symptoms, including spontaneous bowel movement frequency, significantly improved compared with those before treatment. Serious adverse events did not occur.

CONCLUSIONS

DA-9701 accelerates colonic transit and safely improves symptoms in patients with functional constipation. Therefore, we suggest that this novel agent could help to treat patients with this condition.

Effect of nitrergic system on colonic motility in a rat model of irritable bowel syndrome

AIM

The aim of this study is to investigate whether nitric oxide (NO)-mediated colonic motility was altered in rat irritable bowel syndrome (IBS) model, using different isoforms of NO-synthase (NOS) inhibitors.

MATERIALS AND METHODS

The animal model of IBS-like visceral hypersensitivity was induced by intra-colonic infusion of 0.5% acetic acid (AA) in saline once daily from postnatal days 8 to 21. Control animals received saline instead of AA. Experiments were performed at the end of 8 weeks. Distal colon tissues were resected and direct effects of different NOS inhibitors; N-omega-nitro-L-arginine methyl ester hydrochloride, (L-NAME), ARL-17477 dihydrochloride hydrate (ARL 17477), N-[3-(Aminomethyl) phenyl] methyl]-ethanimidamidedihydrochloride (1400 W), and N5-(1-Iminoethyl)-L-ornithine dihydrochloride (L-NIO) were evaluated concentration-dependently in vitro tissue bath. Besides, morphology of both groups was assessed with hematoxylin and eosin (H and E) staining and the impact of NO antibodies was determined using the immunohistochemical method.

RESULTS

The mean pressure values of spontaneous contractions and KCL (80 mmol/L) responses of distal colonic segments were similar in normal and IBS rats. L-NAME and ARL-17477 significantly increased the mean pressure of spontaneous colonic contractions in normal rats versus own base values (P < 0.05), but this increase did not significantly different when compared to IBS rats. In H and E staining, there was no difference with regard to morphology between two groups. Neuronal NOS (nNOS) immunoreactivity was found to be significantly decreased in IBS when compared to control groups (P < 0.05).

CONCLUSION

L-NAME and ARL-17477 mediated mean pressure values were found to be slightly decreased in IBS rats. These findings may be related to a decrease in nNOS level in IBS.

Cyproheptadine: A Potentially Effective Treatment for Functional Gastrointestinal Disorders in Children

Functional gastrointestinal disorders (FGIDs) negatively affect children's quality of life and health care costs. It has been proposed that alteration of gut serotonin leads to gastrointestinal dysmotility, visceral hypersensitivity, altered gastrointestinal secretions, and brain-gut dysfunction. Cyproheptadine, a serotonin antagonist, has been shown to be a potentially effective and safe treatment option in children who meet the clinical criteria for FGIDs. Well-designed multicenter trials with long-term follow-up are needed to further investigate its efficacy. [Pediatr Ann. 2017;46(3):e120-e125.].

Recent advances in the diagnosis of irritable bowel syndrome

The symptom-based diagnosis of irritable bowel syndrome (IBS) has not been established in everyday clinical practice, and the diagnosis of this disorder remains one of exclusion. It has been demonstrated that the densities of duodenal chromogranin A, rectal peptide YY and somatostatin cells are good biomarkers for the diagnosis of sporadic IBS, and low-grade mucosal inflammation is a promising biomarker for the diagnosis of postinfectious IBS. Genetic markers are not useful as biomarkers for IBS since the potential risk genes have yet to be validated, and the intestinal microbiota cannot be used because of the lack of an association between a specific bacterial species and IBS. Furthermore, gastrointestinal dysmotility and visceral hypersensitivity tests produce results that are too nonconsistent and noncharacteristic to be used in the diagnosis of IBS. A combination of symptom-based assessment, exclusion of overlapping gastrointestinal diseases and positive biomarkers appears to be the best way to diagnose IBS.

Clozapine-treated Patients Have Marked Gastrointestinal Hypomotility, the Probable Basis of Life-threatening Gastrointestinal Complications: A Cross Sectional Study

BACKGROUND

Gastrointestinal side effects are particularly common with clozapine and occur with other antipsychotics, ranging from mild constipation to fatal bowel obstruction and/or ischemia. While this adverse-effect spectrum has been attributed to 'gastrointestinal hypomotility', gastrointestinal transit times in antipsychotic-treated patients have not previously been measured, making this mechanism speculative.

METHODS

Using standardized radiopaque marker ('Metcalf') methods we established colonic transit times of antipsychotic-treated psychiatric inpatients and compared them with population normative values. We analyzed results by antipsychotic type, antipsychotic dose equivalent, anticholinergic load, duration of treatment, gender, ethnicity, and age.

OUTCOMES

For patients not prescribed clozapine, median colonic transit time was 23 h. For patients prescribed clozapine, median transit time was 104.5 h, over four times longer than those on other antipsychotics or normative values (p < 0.0001). Eighty percent of clozapine-treated patients had colonic hypomotility, compared with none of those prescribed other antipsychotics (olanzapine, risperidone, paliperidone aripiprazole, zuclopenthixol or haloperidol). In the clozapine group, right colon, left colon and rectosigmoid transit times were all markedly abnormal suggesting pan-colonic pathology. Hypomotility occurred irrespective of gender, age, ethnicity, or length of clozapine treatment. Transit times were positively correlated with clozapine plasma level (rho = 0.451, p = 0.045), but not with duration of treatment, total antipsychotic load or demographic factors.

INTERPRETATION

Clozapine, unlike the other antipsychotics examined, causes marked gastrointestinal hypomotility, as previously hypothesized. Pre-emptive laxative treatment is recommended when starting clozapine.

Colon Transit Time Test in Korean Children with Chronic Functional Constipation

PURPOSE

Each ethnic group has a unique life style, including diets. Life style affects bowel movement. The aim of this study is to describe the results of colon transit time (CTT) tests in Korean children who had chronic functional constipation based on highly refined data.

METHODS

One hundred ninety (86 males) out of 415 children who performed a CTT test under the diagnosis of chronic constipation according to Rome III criteria at Konkuk University Medical Center from January 2006 through March 2015 were enrolled in this study. Two hundreds twenty-five children were excluded on the basis of CTT test result, defecation diary, and clinical setting. Shapiro-Wilk and Mann-Whitney U, and chi-square tests were used for statistical analysis.

RESULTS

The median value and interquartile range (IQR) of CTT was 54 (37.5) hours in Encopresis group, and those in non-encopresis group was 40.2 (27.9) hours (p<0.001). The frequency of subtype between non-encopresis group and encopresis was statistically significant (p=0.002). The non-encopresis group (n=154, 81.1%) was divided into normal transit subgroup (n=84, 54.5%; median value and IQR of CTT=26.4 [9.6] hours), outlet obstruction subgroup (n=18, 11.7%; 62.4 [15.6] hours), and slow transit subgroup (n=52, 33.8%; 54.6 [21.0] hours]. The encopresis group (n=36, 18.9%) was divided into normal transit subgroup (n=8, 22.2%; median value and IQR of CTT=32.4 [9.9] hours), outlet obstruction subgroup (n=8, 22.2%; 67.8 [34.8] hours), and slow transit subgroup (n=20, 55.6%; 59.4 [62.7]hours).

CONCLUSION

This study provided the basic pattern and value of the CTT test in Korean children with chronic constipation.

Inflammation in irritable bowel syndrome: Myth or new treatment target?

Low-grade intestinal inflammation plays a key role in the pathophysiology of irritable bowel syndrome (IBS), and this role is likely to be multifactorial. The aim of this review was to summarize the evidence on the spectrum of mucosal inflammation in IBS, highlighting the relationship of this inflammation to the pathophysiology of IBS and its connection to clinical practice. We carried out a bibliographic search in Medline and the Cochrane Library for the period of January 1966 to December 2014, focusing on publications describing an interaction between inflammation and IBS. Several evidences demonstrate microscopic and molecular abnormalities in IBS patients. Understanding the mechanisms underlying low-grade inflammation in IBS may help to design clinical trials to test the efficacy and safety of drugs that target this pathophysiologic mechanism.

Corticotropin-releasing factor receptor type 1 and type 2 interaction in irritable bowel syndrome

Irritable bowel syndrome (IBS) displays chronic abdominal pain or discomfort with altered defecation, and stress-induced altered gut motility and visceral sensation play an important role in the pathophysiology. Corticotropin-releasing factor (CRF) is a main mediator of stress responses and mediates these gastrointestinal functional changes. CRF in brain and periphery acts through two subtype receptors such as CRF receptor type 1 (CRF1) and type 2 (CRF2), and activating CRF1 exclusively stimulates colonic motor function and induces visceral hypersensitivity. Meanwhile, several recent studies have demonstrated that CRF2 has a counter regulatory action against CRF1, which may imply that CRF2 inhibits stress response induced by CRF1 in order to prevent it from going into an overdrive state. Colonic contractility and sensation may be explained by the state of the intensity of CRF1 signaling. CRF2 signaling may play a role in CRF1-triggered enhanced colonic functions through modulation of CRF1 activity. Blocking CRF2 further enhances CRF-induced stimulation of colonic contractility and activating CRF2 inhibits stress-induced visceral sensitization. Therefore, we proposed the hypothesis, i.e., balance theory of CRF1 and CRF2 signaling as follows. Both CRF receptors may be activated simultaneously and the signaling balance of CRF1 and CRF2 may determine the functional changes of gastrointestinal tract induced by stress. CRF signaling balance might be abnormally shifted toward CRF1, leading to enhanced colonic motility and visceral sensitization in IBS. This theory may lead to understanding the pathophysiology and provide the novel therapeutic options targeting altered signaling balance of CRF1 and CRF2 in IBS.

Recent developments in the pathophysiology of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder, the pathophysiology of which is not completely known, although it has been shown that genetic/social learning factors, diet, intestinal microbiota, intestinal low-grade inflammation, and abnormal gastrointestinal endocrine cells play a major role. Studies of familial aggregation and on twins have confirmed the heritability of IBS. However, the proposed IBS risk genes are thus far nonvalidated hits rather than true predisposing factors. There is no convincing evidence that IBS patients suffer from food allergy/intolerance, with the effect exerted by diet seemingly caused by intake of poorly absorbed carbohydrates and fiber. Obesity is a possible comorbidity of IBS. Differences in the microbiota between IBS patients and healthy controls have been reported, but the association between IBS symptoms and specific bacterial species is uncertain. Low-grade inflammation appears to play a role in the pathophysiology of a major subset of IBS, namely postinfectious IBS. The density of intestinal endocrine cells is reduced in patients with IBS, possibly as a result of genetic factors, diet, intestinal microbiota, and low-grade inflammation interfering with the regulatory signals controlling the intestinal stem-cell clonogenic and differentiation activities. Furthermore, there is speculation that this decreased number of endocrine cells is responsible for the visceral hypersensitivity, disturbed gastrointestinal motility, and abnormal gut secretion seen in IBS patients.

Association between the location of diverticular disease and the irritable bowel syndrome: a multicenter study in Japan

OBJECTIVES

No previous reports have shown an association between location of diverticular disease (DD) and the irritable bowel syndrome (IBS).

METHODS

We included 1,009 consecutive patients undergoing total colonoscopy in seven centers in Japan from June 2013 to September 2013. IBS was diagnosed using Rome III criteria, and diverticulosis was diagnosed by colonoscopy with transparent soft-short-hood. Left-sided colon was defined as sigmoid colon, descending colon, and rectum. Right-sided colon was defined as cecum, ascending colon, and transverse colon. We divided the patients into IBS and non-IBS groups and compared characteristics.

RESULTS

Patient characteristics included mean age, 64.2±12.9 years and male:female ratio, 1.62:1. Right-sided DD was identified in 21.6% of subjects. Left-sided and bilateral DD was identified in 6.6 and 12.0% of subjects, respectively. IBS was observed in 7.5% of subjects. Multiple logistic regression analysis showed left-sided DD (odds ratio, 3.1; 95% confidence interval (CI): 1.4-7.1; P=0.0060) and bilateral DD (odds ratio, 2.6; 95% CI, 1.3-5.2; P=0.0070) were independent risk factors for IBS. Right-sided DD was not a risk factor for IBS.

CONCLUSIONS

Our data showed that the presence of left-sided and bilateral DD, but not right-sided disease, was associated with a higher risk of IBS, indicating that differences in pathological factors caused by the location of the DD are important in the development of IBS. Clarifying the specific changes associated with left-sided DD could provide a better understanding of the pathogenic mechanisms of IBS (Trial registration # R000012739).

Interaction between ingested nutrients and gut endocrine cells in patients with irritable bowel syndrome (review)

Several endocrine cell abnormalities have been reported in different segments of the gastrointestinal tract of patients with irritable bowel syndrome (IBS). These cells have specialized microvilli that project into the lumen; they function as sensors for the gut contents and respond to luminal stimuli (mostly ingested nutrients) by releasing hormones into the lamina propria, where they exert their effects via a paracrine/endocrine mode of action. Certain food items trigger the symptoms experienced by IBS patients, including those rich in fermentable oligo-, di- and monosaccharides, and polyols (FODMAPs). In this review, we present the argument that the effects of both FODMAPs and the proportional intake of proteins, fats and carbohydrates on IBS symptoms may be caused by an interaction with the gut endocrine cells. Since the gut hormones control and regulate gastrointestinal motility and sensation, this interaction may be responsible for abnormal gastrointestinal motility and the visceral hypersensitivity observed in these patients. There is no consistent evidence that IBS patients suffer from food allergy. The role of gluten intolerance in the development of IBS symptoms in these patients remains a matter of controversy. Individual guidance on food management, which includes restrictions in the intake of FODMAP-rich foods and testing diets with different proportions of proteins, fats and carbohydrates has been found to reduce the symptoms, improve the quality of life, and make the habitual diet of IBS patients more healthy.

Irritable bowel syndrome: The evolution of multi-dimensional looking and multidisciplinary treatments

Irritable bowel syndrome (IBS) is common in the society. Among the putative pathogeneses, gut dysmotility results in pain and disturbed defecation. The latter is probably caused by the effect of abnormal gut water secretion. The interaction between abnormal gas accumulation, abdominal pain and bloating remains controversial. Visceral hypersensitivity and its modification along with the central transmission are the characteristics of IBS patients. The identification of biologic markers based on genetic polymorphisms is undetermined. Imbalanced gut microbiota may alter epithelial permeability to activate nociceptive sensory pathways which in turn lead to IBS. Certain food constituents may exacerbate bowel symptoms. The impact of adult and childhood abuses on IBS is underestimated. Using the concept of biopsychosocial dysfunction can integrate multidimensional pathogeneses. Antispasmodics plus stool consistency modifiers to treat the major symptoms and defecation are the first-line drug treatment. New drugs targeting receptors governing bowel motility, sensation and secretion can be considered, but clinicians must be aware of their potential serious side effects. Psychiatric drugs and modalities may be the final options for treating intractable subjects. Probiotics of multi-species preparations are safe and worth to be considered for the treatment. Antibiotics are promising but their long-term safety and effectiveness are unknown. Diet therapy including exclusion of certain food constituents is an economic measure. Using relatively safe complementary and alternative medicines (CAMs) may be optional to those patients who failed classical treatment. In conclusion, IBS is a heterogeneous disorder with multidimensional pathogeneses. Personalized medicines with multidisciplinary approaches using different classes of drugs, psychiatric measures, probiotics and antibiotics, dietary therapy, and finally CAMs, can be considered.

Is irritable bowel syndrome an organic disorder?

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that is generally considered to be functional because there appears to be no associated anatomical defect. Stress and psychological factors are thought to play an important role in IBS. The gut neuroendocrine system (NES), which regulates all functions of the gastrointestinal tract, consists of endocrine cells that are scattered among the epithelial cells of the mucosa, and the enteric nervous system. Although it is capable of operating independently from the central nervous system (CNS), the gut NES is connected to and modulated by the CNS. This review presents evidence for the presence of an anatomical defect in IBS patients, namely in the gastrointestinal endocrine cells. These cells have specialized microvilli that project into the lumen and function as sensors for the luminal content and respond to luminal stimuli by releasing hormones into the lamina propria, which starts a chain reaction that progresses throughout the entire NES. The changes in the gastrointestinal endocrine cells observed in IBS patients are highly consistent with the other abnormalities reported in IBS patients, such as visceral hypersensitivity, dysmotility, and abnormal secretion.

Abdominal bloating: pathophysiology and treatment

Abdominal bloating is a very common and troublesome symptom of all ages, but it has not been fully understood to date. Bloating is usually associated with functional gastrointestinal disorders or organic diseases, but it may also appear alone. The pathophysiology of bloating remains ambiguous, although some evidences support the potential mechanisms, including gut hypersensitivity, impaired gas handling, altered gut microbiota, and abnormal abdominal-phrenic reflexes. Owing to the insufficient understanding of these mechanisms, the available therapeutic options are limited. However, medical treatment with some prokinetics, rifaximin, lubiprostone and linaclotide could be considered in the treatment of bloating. In addition, dietary intervention is important in relieving symptom in patients with bloating.

Characteristics of gastrointestinal symptoms and function following endoscopic submucosal dissection and treatment of the gastrointestinal symptoms using rikkunshito

The aim of the present study was to investigate the gastrointestinal (GI) symptoms and gastric emptying following endoscopic submucosal dissection (ESD), as well as to evaluate a novel treatment strategy using rikkunshito, a traditional Japanese herbal medicine. GI symptoms and gastric emptying were evaluated 6–8 days after ESD as part of the Step I study. In the Step 1 study, the Gastrointestinal Symptom Rating Scale (GSRS) scores of the two groups after 4 and 8 weeks of treatment with either a proton pump inhibitor (PPI; PPI monotreatment group, n=5) or a PPI plus rikkunshito (PPI + rikkunshito group, n=8) were compared against baseline values. Abdominal pain and constipation occurred in the majority of patients after ESD. The mean T-max 6–8 days after gastric emptying was 75.4±13.6 min, which was significantly longer compared with that reported in healthy subjects (43.9±10.3 min). In the Step 2 study, the total GSRS score was significantly improved only in the PPI + rikkunshito group after 8 weeks of treatment. In conclusion, ESD affects gastric emptying and is associated with an increased incidence of upper GI symptoms such as abdominal pain and indigestion. Rikkunshito may be useful as a novel supporting therapeutic drug for the treatment of GI symptoms in patients who have undergone ESD.

Irritable bowel syndrome and the elusive mast cells

Irritable bowel syndrome (IBS) is the most common condition seen by gastroenterologists. It presents with alternating symptoms of bowel dysfunction that often worsens with stress. The cause of these symptoms eludes investigators and many attempts have been made to discover an underlying pathology. This is a daunting task since symptoms come and go, and change characteristics. Furthermore, the pathology of IBS is unlikely to be identical in all patients. In addition, all symptoms and all features studied thus far have a strong overlap with healthy volunteers. Elsewhere in this issue, Braak et al. report a well-designed clinical investigation in patients with IBS and come to the conclusion that IBS is not characterized by mast cell or other immune cell proliferation, but by immune dysregulation in the colon. Is this the final answer?

Plasma hormones facilitated the hypermotility of the colon in a chronic stress rat model

Objective

To study the relationship between brain-gut peptides, gastrointestinal hormones and altered motility in a rat model of repetitive water avoidance stress (WAS), which mimics the irritable bowel syndrome (IBS).

Methods

Male Wistar rats were submitted daily to 1-h of water avoidance stress (WAS) or sham WAS (SWAS) for 10 consecutive days. Plasma hormones were determined using Enzyme Immunoassay Kits. Proximal colonic smooth muscle (PCSM) contractions were studied in an organ bath system. PCSM cells were isolated by enzymatic digestion and IKv and IBKca were recorded by the patch-clamp technique.

Results

The number of fecal pellets during 1 h of acute restraint stress and the plasma hormones levels of substance P (SP), thyrotropin-releasing hormone (TRH), motilin (MTL), and cholecystokinin (CCK) in WAS rats were significantly increased compared with SWAS rats, whereas vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP) and corticotropin releasing hormone (CRH) in WAS rats were not significantly changed and peptide YY (PYY) in WAS rats was significantly decreased. Likewise, the amplitudes of spontaneous contractions of PCSM in WAS rats were significantly increased comparing with SWAS rats. The plasma of WAS rats (100 µl) decreased the amplitude of spontaneous contractions of controls. The IKv and IBKCa of PCSMs were significantly decreased in WAS rats compared with SWAS rats and the plasma of WAS rats (100 µl) increased the amplitude of IKv and IBKCa in normal rats.

Conclusion

These results suggest that WAS leads to changes of plasma hormones levels and to disordered myogenic colonic motility in the short term, but that the colon rapidly establishes a new equilibrium to maintain the normal baseline functioning.

How to interpret a functional or motility test - colon transit study

Measurement of colon transit time is the most basic and primary tool in evaluating disorders of colonic motility. In particular, it is helpful in pathologic diagnosis and for planning management in patients with constipation. Several techniques for measuring colon transit time currently exist. The standard measurement of colon transit time has been performed using radioopaque marker test. The radioopaque marker test is the most widely used method; it is simple to perform as well as being cost effective. But, this technique produces radiation exposure. Radionuclide scintigraphy and wireless motility capsules are other techniques used to measure colon transit time. In radionuclide scintigraphy, the transit of radioisotope is viewed by gamma camera; this approach has an advantage in that it uses minimal radiation and it allows a physiological assessment of gastrointestinal transit. Wireless motility capsules have been validated most recently, but this technique is not useful in Korea. This review presents the techniques used to measure colon transit time and the interpretations provided in different colon transit studies.

The evaluation of otilonium bromide treatment in asian patients with irritable bowel syndrome

Background/Aims

Antispasmodics including otilonium bromide (OB) are recommended to treat irritable bowel syndrome (IBS). However, reports about OB experience in Asia is sparse. The purpose of present study was to provide the efficacy of OB in treating Asian IBS patients.

Methods

Overall, 117 IBS patients meeting Rome II criteria were enrolled in an 8-week, double-blind, active-controlled and single center trial. Randomized participants received either OB 40 mg or mebeverine 100 mg 3 doses daily. The primary endpoints were to evaluate the net changes of abdominal pain/discomfort frequency score (APDFS) and safety profile, while the secondary endpoints were to assess the changes in abdominal pain/discomfort intensity, flatulence, abdominal bloating, satisfied stool frequency etc.

Results

Finally, 49 OB and 52 mebeverine subjects were eligible for efficacy analysis. Compared to baselines in per protocol populations, the reduced APDFSs in OB and mebeverine were 0.55 ± 1.20 (P = 0.011) and 0.37 ± 1.11 (P = 0.042), respectively, to show similarly reduced scores. The most reported side effects included dry mouth, nausea and dizziness. Besides, the improved APDFSs at 4th week visit, final alleviations in abdominal pain intensity, flatulence, abdominal bloating and satisfied stool frequency with global assessments filled by both patients and investigators were significantly achieved by both treatments, and OB was not inferior to mebeverine in treating these parameters.

Conclusions

In Orientals, OB is as effective as mebeverine for alleviating IBS symptoms in terms of abdominal pain, flatulence, abdominal bloating etc. However, obvious side effects are also observed. A large-scaled trial and post-marketing surveillance are recommended to confirm its efficacy and safety.

Pharmacologic and complementary and alternative medicine therapies for irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by episodic abdominal pain or discomfort in association with altered bowel habits (diarrhea and/or constipation). Other gastrointestinal symptoms, such as bloating and flatulence, are also common. A variety of factors are believed to play a role in the development of IBS symptoms, including altered bowel motility, visceral hypersensitivity, psychosocial stressors, altered brain-gut interactions, immune activation/low grade inflammation, alterations in the gut microbiome, and genetic factors. In the absence of biomarkers that can distinguish between IBS subgroups on the basis of pathophysiology, treatment of this condition is predicated upon a patient's most bothersome symptoms. In clinical trials, effective therapies have only offered a therapeutic gain over placebos of 7-15%. Evidence based therapies for the global symptoms of constipation predominant IBS (IBS-C) include lubiprostone and tegaserod; evidence based therapies for the global symptoms of diarrhea predominant IBS (IBS-D) include the probiotic Bifidobacter infantis, the nonabsorbable antibiotic rifaximin, and alosetron. Additionally, there is persuasive evidence to suggest that selected antispasmodics and antidepressants are of benefit for the treatment of abdominal pain in IBS patients. Finally, several emerging therapies with novel mechanisms of action are in development. Complementary and alternative medicine therapies including probiotics, herbal therapies and acupuncture are gaining popularity among IBS sufferers, although concerns regarding manufacturing standards and the paucity of high quality efficacy and safety data remain.

Peripherally acting therapies for the treatment of irritable bowel syndrome

Gut-acting therapies are common therapies for irritable bowel syndrome (IBS). Most of these peripheral acting agents are primarily targeted at individual symptoms. The evidence supporting the use of these agents in IBS is largely anecdotal. Serotonergic agents and the chloride channel activator lubiprostone have shown efficacy in treating symptoms of IBS. The clinical evidence supporting the use of these agents is based on data from high-quality clinical trials. The use of serotonergic agents for IBS in the United States is limited to the 5-hydroxytryptamine-3 antagonist alosetron in the treatment of women with severe IBS with diarrhea refractory to traditional therapy.