High-resolution colonic manometry accurately predicts colonic neuromuscular pathological phenotype in pediatric slow transit constipation

Diagnostic and therapeutic approach to children with chronic refractory constipation: Consensus report by the SIGENP motility working group

Constipation is a common problem in children, accounting for about 3% of all primary care visits and up to 25% of referrals to paediatric gastroenterologists. Although polyethylene glycol often proves effective, most children require prolonged treatment and about 50% of them have at least one relapse within the first 5 years after initial recovery. When conventional treatment fails, children are considered to have refractory constipation. Children with refractory constipation deserve specialist management and guidance. Over the last decades, there has been a remarkable increase in our knowledge of normal and abnormal colonic and anorectal motility in children, and a number of different techniques to measure transit and motility have been developed. The present review analyses the possible diagnostic investigations for children with refractory constipation, focusing on their actual indications and their utility in clinical practice. Moreover, we have also analytically reviewed medical and surgical therapeutic options, which should be considered in selected patients in order to achieve the best clinical outcome.

Abnormal gastrointestinal motility is a major factor in explaining symptoms and a potential therapeutic target in patients with disorders of gut-brain interaction

The objective of this article is to review the evidence of abnormal gastrointestinal (GI) tract motor functions in the context of disorders of gut-brain interaction (DGBI). These include abnormalities of oesophageal motility, gastric emptying, gastric accommodation, colonic transit, colonic motility, colonic volume and rectal evacuation. For each section regarding GI motor dysfunction, the article describes the preferred methods and the documented motor dysfunctions in DGBI based on those methods. The predominantly non-invasive measurements of gut motility as well as therapeutic interventions directed to abnormalities of motility suggest that such measurements are to be considered in patients with DGBI not responding to first-line approaches to behavioural or empirical dietary or pharmacological treatment.

Diagnostic Utility of Mucosal Biopsies Taken During Colonoscopy-Guided Colonic Manometry Catheter Placement

OBJECTIVES

The diagnostic utility of mucosal biopsies taken during colonoscopy-guided colonic manometry catheter placement is unknown. The aims of our study were to determine the frequency and histopathology results of mucosal biopsies during these procedures and to assess whether there were any associations between the histology or gross findings with manometry results.

METHODS

We performed a retrospective chart review of children who had a colonic manometry study completed between 2008 and 2020 at a quaternary children's hospital. We captured patient demographics, biopsy locations, histopathology results, gross endoscopy findings, and manometry results. The chi-squared test and when appropriate Fisher exact test was used to evaluate categorical associations.

RESULTS

One hundred forty-eight patients were included. One hundred eighteen (80%) had colonic biopsy and 63 (43%) had ileal biopsy. Colonic histology findings, which patients could have multiple, included lymphonodular hyperplasia (34%), normal (27%), chronic inflammation (24%), melanosis coli (21%), colonic eosinophilia (10%), and acute inflammation (8%). Ileal histology findings included increased Peyer patches (44%), normal (44%), acute inflammation (11%), chronic inflammation (3%), eosinophilia (5%), and eosinophilic ileitis (3%). The majority of acute and chronic inflammation was graded as mild. There were no statistically significant associations of histology to gross endoscopy or manometry findings.

CONCLUSIONS

Colonic biopsies are obtained in the majority of patients presenting for colonic manometry evaluation with ileal biopsies obtained less frequently. Histopathology findings are noted frequently, but the majority are the result of or did not impact clinical care. There were no associations between abnormal histopathology or abnormal gross endoscopy findings with colonic manometry results.

Characteristics of the Cajal interstitial cells and intestinal microbiota in children with refractory constipation

BACKGROUND

Children with refractory constipation experience intense and persistent symptoms that greatly diminish their quality of life. However, the underlying pathophysiological mechanism responsible for this condition remains uncertain. Our objective was to evaluate characteristics of colonic motor patterns and interstitial cells of Cajal (ICCs) to refractory constipation children, as well as intestinal microbiota compositions.

METHODS

Colonic manometry (CM) was conducted on a cohort of 30 patients with refractory constipation to assess colonic motility, and 7 of them underwent full-thickness colon biopsy specimens. Another 5 colonic specimens from nonconstipation patients were collected to identify the ICCs by immunohistochemistry. Fecal samples from 14 children diagnosed with refractory constipation and subjecting 28 age-matched healthy children to analysis using high-throughput sequencing of 16S rRNA.

RESULTS

According to CM results, dividing 30 children with refractory constipation into 2 groups: normal group (n = 10) and dysmotility group (n = 20). Dysmotility subjects showed lower colonic motility. Antegrade propagating pressure waves, retrograde propagating pressure waves, and periodic colonic motor activity were common in normal subjects and rare in dysmotility subjects (32.7 ± 8.9 vs 20.7 ± 13.0/17 h, P < 0.05, 11.5 ± 2.3 vs 9.6 ± 2.3/17 h, P < 0.05, and 5.2 ± 8.9 vs 3.5 ± 6.8 cpm, P < 0.005, respectively), whereas periodic rectal motor activity was more common in dysmotility subjects (3.4 ± 4.8 vs 3.0 ± 3.1 cpm, P < 0.05). Dysmotility subjects exhibited a significantly greater number of preprandial simultaneous pressure waves compared to the normal subjects (32.3 ± 25.0 vs 23.6 ± 13.2/1 h, P < 0.005). Dysmotility subjects displayed a notable decrease in postprandial count of antegrade propagating pressure waves and high amplitude propagating pressure waves when compared to normal subjects (3.9 ± 2.9 vs 6.9 ± 3.5/1 h and 2.3 ± 1.5 vs 5.4 ± 2.9/1 h, respectively, P < 0.05). The number, distribution, and morphology of ICCs were markedly altered in refractory constipation compared children to the controls (P < 0.05). Children diagnosed with refractory constipation displayed a distinct dissimilarity in composition of their intestinal microbiota comparing with control group (P < 0.005). In genus level, Bacteroidetes represented 34.34% and 43.78% in the refractory constipation and control groups, respectively. Faecalibacterium accounted for 3.35% and 12.56%, respectively (P < 0.005). Furthermore, the relative abundances of Faecalibacterium (P < 0.005), Lachnospira (P < 0.05), and Haemophilus (P < 0.05) significantly decreased, whereas those of Parabacteroides (P < 0.05), Alistipes (P < 0.005), Prevotella_2 (P < 0.005), [Ruminococcus]_torques_group (P < 0.005), Barnesiella (P < 0.05), Ruminococcaceae_UCG-002 (P < 0.005), and Christensensenellaceae_R-7_group (P < 0.05) were markedly increased in children with refractory constipation.

CONCLUSIONS

Dysmotility subjects showed lower colonic motility and an impaired postprandial colonic response. The decreased number and abnormal morphology of colonic ICCs may contribute to the pathogenesis of refractory constipation. Children with refractory constipation exhibited significant variations in microbiota composition across various taxonomic levels compared to the healthy control group. Our findings contribute valuable insights into pathophysiological mechanism underlying refractory constipation and provide evidence to support the exploration of novel therapeutic strategies for affected children.

Clinical utility of colonic low-amplitude propagating contractions in children with functional constipation

BACKGROUND

Colonic high-amplitude propagating contractions (HAPC) are generally accepted as a marker of neuromuscular integrity. Little is known about low-amplitude propagating contractions (LAPCs); we evaluated their clinical utility in children.

METHODS

Retrospective review of children with functional constipation undergoing low-resolution colon manometry (CM) recording HAPCs and LAPCs (physiologic or bisacodyl-induced) in three groups: constipation, antegrade colonic enemas (ACE), and ileostomy. Outcome (therapy response) was compared to LAPCs in all patients and within groups. We evaluated LAPCs as potentially representing failed HAPCs.

KEY RESULTS

A total of 445 patients were included (median age 9.0 years, 54% female), 73 had LAPCs. We found no association between LAPCs and outcome (all patients, p = 0.121), corroborated by logistic regression and excluding HAPCs. We found an association between physiologic LAPCs and outcome that disappears when excluding HAPCs or controlling with logistic regression. We found no association between outcome and bisacodyl-induced LAPCs or LAPC propagation. We found an association between LAPCs and outcome only in the constipation group that cancels with logistic regression and excluding HAPCs (p = 0.026, 0.062, and 0.243, respectively). We found a higher proportion of patients with LAPCs amongst those with absent or abnormally propagated (absent or partially propagated) HAPCs compared to those with fully propagated HAPCs (p = 0.001 and 0.004, respectively) suggesting LAPCs may represent failed HAPCs.

CONCLUSIONS/INFERENCES

LAPCs do not seem to have added clinical significance in pediatric functional constipation; CM interpretation could rely primarily on the presence of HAPCs. LAPCs may represent failed HAPCs. Larger studies are needed to further validate these findings.

The colonic motility and classification of patients with slow transit constipation by high-resolution colonic manometry

BACKGROUND

This study aimed to evaluate the colonic motility of slow transit constipation (STC) patients using high-resolution colonic manometry (HRCM) and classify the patients' subtypes to instruct treatment based on HRCM characteristics.

METHODS

This study enrolled one hundred and twenty-six STC patients and 35 volunteers (healthy controls, HCs). Ambulatory HRCM was performed in all participants by placing a 36-sensor water-perfused probe up to the cecum. Quantitative and qualitative manometric analysis was conducted in the state of rest, postprandial, during sleep, and wakefulness.

RESULTS

The occurrence rate and times of high amplitude propagated contraction (HAPC) in STC patients were lower than HCs. As for the HAPC contraction characteristics, the mean velocity was similar, contraction length, amplitude, area under the curve (AUC) of pressure wave, and duration were reduced in STC patients compared with HCs. In addition, the occurrence rate and times of low amplitude propagated contraction (LAPC) in STC patients were similar compared to HCs. There was no difference in HAPC occurrence, LAPC occurrence, and most detailed HAPC characteristics between STC patients ≤60 years and STC patients >60 years or between male STC patients and female STC patients. Based on the HRCM characteristics (including HAPC, neostigmine induced HAPC, LAPC, and waking/gastrocolic response), STC patients were classified into four types, respectively, with recommended treatment by clinical experience.

CONCLUSION

HRCM serves as a valuable tool in characterizing, classifying the pathophysiology, and guiding clinical management for STC.

Childhood constipation: Current status, challenges, and future perspectives

Constipation in children is a major health issue around the world, with a global prevalence of 9.5%. They present to clinicians with a myriad of clinical signs. The Rome IV symptom-based criteria are used to diagnose functional constipation. Functional constipation is also a huge financial burden for healthcare system and has a detrimental impact on health-related quality of life of children. There are various risk factors identified globally, including centrally connected factors such as child abuse, emotional and behavioral issues, and psychological stress. Constipation is also precipitated by a low-fiber diet, physical inactivity, and an altered intestinal microbiome. The main pathophysiological mechanism is stool withholding, while altered rectal function, anal sphincter, pelvic floor, and colonic dysfunction also play important roles. Clinical evaluation is critical in making a diagnosis, and most investigations are only required in refractory patients. In the treatment of childhood constipation, both nonpharmacological (education and de-mystification, dietary changes, toilet training, behavioral interventions, biofeedback, and pelvic floor physiotherapy), and pharmacological (osmotic and stimulant laxatives and novel drugs like prucalopride and lubiprostone) interventions are used. For children with refractory constipation, transanal irrigation, botulinum toxin, neuromodulation, and surgical treatments are reserved. While frequent use of probiotics is still in the experimental stage, healthy dietary habits, living a healthy lifestyle and limiting exposure to stressful events, are all beneficial preventive measures.

Enhancing the utility of antroduodenal manometry in pediatric intestinal pseudo-obstruction

BACKGROUND

Antroduodenal manometry (ADM) and histopathology are currently employed to aid the diagnosis of pediatric intestinal pseudo-obstruction (PIPO). Limited data are available on the reliability of ADM analysis and its correlation with histopathology. We aimed to develop a protocol for enhanced analysis of ADM contractile patterns, including a scoring system, and explore whether this provided better correlation with histopathology.

METHODS

Children referred with suspected PIPO between April 2012-December 2019 who underwent both ADM and full-thickness biopsies were included. ADM tracings were analyzed using both standard (conventional ADM) and novel (enhanced ADM) motility parameters. A novel ADM score (GLASS score) was generated based on the enhanced ADM analysis. Conventional and enhanced ADM analyses were then correlated with histopathology.

RESULTS

Forty patients were included. Using conventional clinical criteria, 29 of these were diagnosed with PIPO and the other 11 with non-PIPO diagnoses. Twenty-three of the PIPO patients had abnormal histopathology: 6 myopathy, 4 neuropathy, 3 neuro-myopathy, and 10 non-specific changes. No agreement in diagnosis was found between conventional ADM analysis and histopathology (ϰ = 0.068; p = 0.197), whereas the latter significantly correlated with enhanced ADM analysis (ϰ = 0.191; p = 0.003). The enhanced ADM score was significantly higher in PIPO versus non-PIPO (16.0 vs. 8.0; p < 0.001).

CONCLUSIONS

As opposed to conventional analysis protocols, the newly developed enhanced ADM analysis and associated score is not only able to discriminate between PIPO and non-PIPO patients, but also between distinct histopathological pathologies. Further studies are required to assess the utility of enhanced ADM analysis in larger populations.

Colonic Function Investigations in Children: Review by the ESPGHAN Motility Working Group

Disorders of colonic motility, most often presenting as constipation, comprise one of the commonest causes of outpatient visits in pediatric gastroenterology. This review, discussed and created by the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Motility Working Group, is a practical guide, which highlights the recent advances in pediatric colonic motility testing including indications, technical principles of the tests, patient preparation, performance and basis of the results' analysis of the tests. classical methods, such as colonic transit time (cTT) with radiopaque markers and colonic scintigraphy, as well as manometry and novel techniques, such as wireless motility capsule and electromagnetic capsule tracking systems are discussed.

Interstitial cells of Cajal and human colon motility in health and disease

Our understanding of human colonic motility, and autonomic reflexes that generate motor patterns, has increased markedly through high-resolution manometry. Details of the motor patterns are emerging related to frequency and propagation characteristics that allow linkage to interstitial cells of Cajal (ICC) networks. In studies on colonic motor dysfunction requiring surgery, ICC are almost always abnormal or significantly reduced. However, there are still gaps in our knowledge about the role of ICC in the control of colonic motility and there is little understanding of a mechanistic link between ICC abnormalities and colonic motor dysfunction. This review will outline the various ICC networks in the human colon and their proven and likely associations with the enteric and extrinsic autonomic nervous systems. Based on our extensive knowledge of the role of ICC in the control of gastrointestinal motility of animal models and the human stomach and small intestine, we propose how ICC networks are underlying the motor patterns of the human colon. The role of ICC will be reviewed in the autonomic neural reflexes that evoke essential motor patterns for transit and defecation. Mechanisms underlying ICC injury, maintenance, and repair will be discussed. Hypotheses are formulated as to how ICC dysfunction can lead to motor abnormalities in slow transit constipation, chronic idiopathic pseudo-obstruction, Hirschsprung's disease, fecal incontinence, diverticular disease, and inflammatory conditions. Recent studies on ICC repair after injury hold promise for future therapies.

Bisacodyl: A review of pharmacology and clinical evidence to guide use in clinical practice in patients with constipation

BACKGROUND

Bisacodyl is a member of the diphenylmethane family and is considered to be a stimulant laxative. It has a dual prokinetic and secretory action and needs to be converted into the active metabolite bis-(p-hydroxyphenyl)-pyridyl-2-methane (BHPM) in the gut to achieve the desired laxative effect. Bisacodyl acts locally in the large bowel by directly enhancing the motility, reducing transit time, and increasing the water content of the stool. A recent network meta-analysis concluded that bisacodyl showed similar efficacy to prucalopride, lubiprostone, linaclotide, tegaserod, velusetrag, elobixibat, and sodium picosulfate for the primary endpoint of ≥3 complete spontaneous bowel movements (CSBM)/week and an increase of ≥1 CSBM/week over baseline. The meta-analysis also found that bisacodyl may be superior to the other laxatives for the secondary endpoint of change from baseline in the number of spontaneous bowel movements per week in patients with chronic constipation. This observation stimulated the authors to review the available literature on bisacodyl, which has been available on the market since the 1950 s.

PURPOSE

The aim of the current review was to provide an overview of the historic background, structure, function, and mechanism of action of bisacodyl. Additionally, we discuss the important features and studies for bisacodyl to understand its peculiar characteristics and guide its use in clinical practice, but also stimulate research on open questions.

Duodenal and proximal jejunal motility inhibition associated with bisacodyl-induced colonic high-amplitude propagating contractions

Bisacodyl is a stimulant laxative often used in manometric studies of pediatric constipation to determine if it can initiate propulsive high-amplitude propagating contractions (HAPCs). Whereas the effects of bisacodyl infusion on colonic motility are well described, the effects of the drug on other regions of the gut after colonic infusion are not known. The aim of the present study was to characterize the effects of bisacodyl on both colonic and small bowel motility. Twenty-seven children (9.3 ± 1.2 yr) undergoing simultaneous high-resolution antroduodenal and colonic manometry were included. Small bowel and colonic motor patterns were assessed before and after colonic infusion of bisacodyl. Patients were divided into two groups: responders and nonresponders based on the presence of high-amplitude propagating contractions (HAPCs) after bisacodyl infusion. Nineteen patients were responders. A total of 188 postbisacodyl HAPCs was identified with a mean count of 10.4 ± 5.5 (range, 3-22), at a frequency of 0.6 ± 0.2/min and mean amplitude of 119.8 ± 23.6 mmHg. No motor patterns were induced in the small bowel. However, in the 19 responders the onset of HAPCs was associated with a significant decrease in small bowel contractile activity. In the nonresponders, there was no detectable change in small bowel motility after bisacodyl infusion. Bisacodyl-induced HAPCs are associated with a significant reduction in small bowel motility probably mediated by extrinsic sympathetic reflex pathways. This inhibition is potentially related to rectal distension, caused by the HAPC anal propulsion of colonic content.NEW & NOTEWORTHY The present study has shown, for the first time, that the presence of high-amplitude propagating contractions induced by bisacodyl is associated with a significant reduction in small bowel motility. These findings support of possible existence of a reflex pathway that causes inhibition of small bowel motility in response to rectal distension.

Dynamic integration of enteric neural stem cells in ex vivo organotypic colon cultures

Enteric neural stem cells (ENSC) have been identified as a possible treatment for enteric neuropathies. After in vivo transplantation, ENSC and their derivatives have been shown to engraft within colonic tissue, migrate and populate endogenous ganglia, and functionally integrate with the enteric nervous system. However, the mechanisms underlying the integration of donor ENSC, in recipient tissues, remain unclear. Therefore, we aimed to examine ENSC integration using an adapted ex vivo organotypic culture system. Donor ENSC were obtained from Wnt1^cre/+;R26R^YFP/YFP mice allowing specific labelling, selection and fate-mapping of cells. YFP⁺ neurospheres were transplanted to C57BL6/J (6–8-week-old) colonic tissue and maintained in organotypic culture for up to 21 days. We analysed and quantified donor cell integration within recipient tissues at 7, 14 and 21 days, along with assessing the structural and molecular consequences of ENSC integration. We found that organotypically cultured tissues were well preserved up to 21-days in ex vivo culture, which allowed for assessment of donor cell integration after transplantation. Donor ENSC-derived cells integrated across the colonic wall in a dynamic fashion, across a three-week period. Following transplantation, donor cells displayed two integrative patterns; longitudinal migration and medial invasion which allowed donor cells to populate colonic tissue. Moreover, significant remodelling of the intestinal ECM and musculature occurred upon transplantation, to facilitate donor cell integration within endogenous enteric ganglia. These results provide critical evidence on the timescale and mechanisms, which regulate donor ENSC integration, within recipient gut tissue, which are important considerations in the future clinical translation of stem cell therapies for enteric disease.

Evaluation of Fecal Incontinence in Pediatric Functional Constipation: Clinical Utility of Anorectal and Colon Manometry

OBJECTIVES

The aim of the study is to evaluate the utility of motility studies in pediatric functional constipation with/without fecal incontinence.

PATIENTS AND METHODS

Patients with functional constipation and failure to conventional therapy undergoing colonic manometry (CM) and/or anorectal manometry (ARM) manometry were classified as functional constipation without fecal incontinence (FC) or with fecal incontinence (FCI). Clinical data, motility parameters, and treatment outcomes were compared.

RESULTS

A total of 280 were included, and all patients underwent CM (229 FC and 51 FCI) and 219 ARM. We found no difference in CM interpretation and presence of normal high amplitude propagating contractions (HAPCs) between groups; however, patients with FCI had higher frequency and presence of HAPCs and normal gastrocolonic meal response (GC). No CM parameter predicted outcomes. In FC, more patients with an abnormal CM responded to therapy compared to those with a normal study (79% vs 65% respectively, P = 0.04). FCI patients had lower median anal resting pressure compared to FC (49 vs 66 mmHg, respectively, P = 0.03); no other ARM parameter differentiated FC from FCI. We found no association between therapy response and ARM interpretation (P = 0.847) or any ARM parameter. A multivariate analysis found only male gender was associated with FCI (P < 0.001).

CONCLUSIONS

FCI patients have higher frequency of normal CM parameters compared to FC, but overall interpretation was no different. CM helped predict response to therapy in FC but not in FCI. ARM demonstrated no added benefit in the evaluation of functional constipation with/without soiling. Patients with both normal ARM and CM had a lower response to therapy than those with abnormal studies.

Simultaneous assessment of colon motility in children with functional constipation by cine-MRI and colonic manometry: a feasibility study

BACKGROUND

Colonic manometry is the current reference standard for assessing colonic neuromuscular function in children with intractable functional constipation (FC). Recently, cine magnetic resonance imaging (cine-MRI) has been proposed as a non-invasive alternative. We compared colonic motility patterns on cine-MRI with those obtained by manometry in children, by stimulating high-amplitude propagating contractions (HAPCs) with bisacodyl under manometric control while simultaneously acquiring cine-MRI.

METHODS

After Institutional Review Board approval, adolescents with FC scheduled to undergo colonic manometry were included. A water-perfused 8-lumen catheter was used for colonic manometry recordings. After an intraluminal bisacodyl infusion, cine-MRI sequences of the descending colon were acquired for about 30 min simultaneously with colonic manometry. Manometry recordings were analysed for HAPCs. MRI images were processed with spatiotemporal motility MRI techniques. The anonymised motility results of both techniques were visually compared for the identification of HAPCs in the descending colon.

RESULTS

Data regarding six patients (three males) were analysed (median age 14 years, range 12-17). After bisacodyl infusion, three patients showed a total of eleven HAPCs with colonic manometry. Corresponding cine-MRI recorded high colonic activity during two of these HAPCs, minimal activity during seven HAPCs, while two HAPCs were not recorded. In two of three patients with absent HAPCs on manometry, colonic activity was recorded with cine-MRI.

CONCLUSIONS

Simultaneous acquisition of colonic cine-MRI and manometry in children with FC is feasible. Their motility results did not completely overlap in the identification of HAPCs. Research is needed to unravel the role of cine-MRI in this setting.

ManoMap: an automated system for characterization of colonic propagating contractions recorded by high-resolution manometry

RATIONALE

Colonic high-resolution manometry (cHRM) is an emerging clinical tool for defining colonic function in health and disease. Current analysis methods are conducted manually, thus being inefficient and open to interpretation bias.

OBJECTIVE

The main objective of the study was to build an automated system to identify propagating contractions and compare the performance to manual marking analysis.

METHODS

cHRM recordings were performed on 5 healthy subjects, 3 subjects with diarrhea-predominant irritable bowel syndrome, and 3 subjects with slow transit constipation. Two experts manually identified propagating contractions, from five randomly selected 10-min segments from each of the 11 subjects (72 channels per dataset, total duration 550 min). An automated signal processing and detection platform was developed to compare its effectiveness to manually identified propagating contractions. In the algorithm, individual pressure events over a threshold were identified and were then grouped into a propagating contraction. The detection platform allowed user-selectable thresholds, and a range of pressure thresholds was evaluated (2 to 20 mmHg).

KEY RESULTS

The automated system was found to be reliable and accurate for analyzing cHRM with a threshold of 15 mmHg, resulting in a positive predictive value of 75%. For 5-h cHRM recordings, the automated method takes 22 ± 2 s for analysis, while manual identification would take many hours.

CONCLUSIONS

An automated framework was developed to filter, detect, quantify, and visualize propagating contractions in cHRM recordings in an efficient manner that is reliable and consistent.

Paediatric constipation for general paediatricians: Review using a case-based and evidence-based approach

Constipation is a common problem in childhood. The most common type of constipation is functional, accounting for 90-95% of all cases. The aim of this review is to provide clinical scenarios with treatment using evidence-based information, and management strategies and a clinical algorithm to guide the management of constipation in children. Recent guidelines and online information sites are detailed. Clinical red flags and organic causes of constipation are included. Four clinical scenarios are presented: case (1) 4-month-old child with constipation since birth and likely Hirschsprung disease; case (2) 6-month-old infant with infant dyschezia; case (3) 4-year old with functional constipation; and; case (4) 9-year old with treatment resistant constipation. Children with functional constipation need a thorough history and physical exam to rule out the presence of any 'red flags' but do not require laboratory investigations. Management includes education and demystification, disimpaction followed by maintenance therapy with oral laxatives, dietary counselling and toilet training. Treatment options differ between infants and children. Disimpaction and maintenance regimens for common laxatives are presented. On treatment failure or on suspicion of organic disease the patient should be referred for further evaluation. The radionuclide intestinal transit study (scintigraphy) is a useful modality for evaluation and planning of management in treatment-resistant children. Treatment options for treatment-resistant patients are presented. High-level evidence (meta-analyses) for pharmalogical and non-pharmalogical treatment modalities are reviewed and an algorithm for assessment and treatment are presented.

Distinct patterns of myogenic motor activity identified in isolated human distal colon with high-resolution manometry

BACKGROUND

Colonic high-resolution manometry (HRM) has been used to reveal discrete, propagating colonic motor patterns. To help determine mechanisms underlying these patterns, we used HRM to record contractile activity in human distal colon ex vivo.

METHODS

Surgically excised segments of descending (n = 30) or sigmoid colon (n = 4) were immersed in oxygenated Krebs solution at 36°C (n = 34; 16 female; 67.6 ± 12.4 years; length: 24.7 ± 3.5 cm). Contractility was recorded by HRM catheters. After 30 minutes of baseline recording, 0.3 mM lidocaine and/or 1 mM hexamethonium were applied. Ascending neural pathways were activated by electrical field stimulation (EFS; 10 Hz, 0.5 ms, 50 V, 5-s duration) applied to the anal end before and after drug application.

RESULTS

Spontaneous propagating contractions were recorded in all specimens (0.1-1.5 cycles/minute). Most contractions occurred synchronously across all recording sites. In five specimens, rhythmic antegrade contractions propagated across the full length of the preparation. EFS evoked local contractions at the site of stimulation (latency: 5.5 ± 2.4 seconds) with greater amplitude than spontaneous contractions (EFS; 29.3 ± 26.9 vs 12.1 ± 14.8 mm Hg; P = .02). Synchronous or retrograde propagating motor patterns followed EFS; 71% spanned the entire preparation length. Hexamethonium and lidocaine modestly and only temporarily inhibited spontaneous contractions, whereas TTX increased the frequency of contractile activity while inhibiting EFS-evoked contractions.

CONCLUSIONS AND INFERENCES

Our study suggests that the propagated contractions recorded in the organ bath have a myogenic origin which can be regulated by neural input. Once activated at a local site, the contractions do not require the propulsion of fecal content to sustain long-distance propagation.

Characterization of the colonic response to bisacodyl in children with treatment-refractory constipation

BACKGROUND

Colonic manometry with intraluminal bisacodyl infusion can be used to assess colonic neuromuscular function in children with treatment-refractory constipation. If bisacodyl does not induce high-amplitude propagating contractions (HAPCs), this can be an indication for surgical intervention. A detailed characterization of the colonic response to intraluminal bisacodyl in children with constipation may help to inform clinical interpretation of colonic manometry studies.

METHODS

Studies were performed in five pediatric hospitals. Analysis included identification of HAPCs, reporting HAPCs characteristics, and an area under the curve (AUC) analysis. Comparisons were performed between hospitals, catheter type, placement techniques, and site of bisacodyl infusion.

RESULTS

One hundred and sixty-five children were included (median age 10, range 1-17 years; n = 96 girls). One thousand eight hundred and ninety-three HAPCs were identified in 154 children (12.3 ± 8.8 HAPCs per child, 0.32 ± 0.21 HAPCs per min; amplitude 113.6 ± 31.5 mm Hg; velocity 8.6 ± 3.8 mm/s, propagation length 368 ± 175 mm). The mean time to first HAPC following bisacodyl was 553 ± 669 s. Prior to the first HAPC, there was no change in AUC when comparing pre- vs post-bisacodyl (Z = -0.53, P = .60). The majority of HAPCs terminated in a synchronous pressurization in the rectosigmoid. Defecation was associated with HAPCs (χ² (1)=7.04, P < .01). Site of bisacodyl administration, catheter type, and hospital location did not alter the response.

CONCLUSIONS AND INFERENCES

Intraluminal bisacodyl induced HAPCs in 93% of children with treatment-refractory constipation. The bisacodyl response is characterized by ≥1 HAPC within 12 minutes of infusion. The majority of HAPCs terminate in a synchronous pressurization in the rectosigmoid. Optimal clinical management based upon colonic manometry findings is yet to be determined.

The cyclic motor patterns in the human colon

BACKGROUND

High-resolution colonic manometry gives an unprecedented window into motor patterns of the human colon. Our objective was to characterize motor activities throughout the entire colon that possessed persistent rhythmicity and spanning at least 5 cm.

METHODS

High-resolution colonic manometry using an 84-channel water-perfused catheter was performed in 19 healthy volunteers. Rhythmic activity was assessed during baseline, proximal balloon distention, meal, and bisacodyl administration.

KEY RESULTS

Throughout the entire colon, a cyclic motor pattern occurred either in isolation or following a high-amplitude propagating pressure wave (HAPW), consisting of clusters of pressure waves at a frequency centered on 11-13 cycles/min, unrelated to breathing. The cluster duration was 1-6 minutes; the pressure waves traveled for 8-27 cm, lasting 5-8 seconds. The clusters itself could be rhythmic at 0.5-2 cpm. The propagation direction of the individual pressure waves was mixed with >50% occurring simultaneous. This high-frequency cyclic motor pattern co-existed with the well-known low-frequency cyclic motor pattern centered on 3-4 cpm. In the rectum, the low-frequency cyclic motor pattern dominated, propagating predominantly in retrograde direction. Proximal balloon distention, a meal and bisacodyl administration induced HAPWs followed by cyclic motor patterns.

CONCLUSIONS AND INFERENCES

Within cyclic motor patterns, retrograde propagating, low-frequency pressure waves dominate in the rectum, likely keeping the rectum empty; and mixed propagation, high-frequency pressure waves dominate in the colon, likely promoting absorption and storage, hence contributing to continence. Propagation and frequency characteristics are likely determined by network properties of the interstitial cells of Cajal.

Does the Oral-Anal Transit Test Correlate with Colonic Manometry Findings in Children with Refractory Constipation?

PURPOSE

The Oral-anal Transit Test (OTT) is a simple method of obtaining information about colonic transit. We aim to assess the correlation of OTT with the neuromuscular integrity of the colon determined by colonic manometry (CM).

METHODS

All patients who had OTT followed by CM were evaluated. Less than 6 of 24 markers remaining on OTT was considered normal. CM was performed per previously published guidelines. A normal CM was defined as at least one High Amplitude Propagating Contraction progressing from the most proximal sensor through the sigmoid colon.

RESULTS

A total of 34 patients underwent both OTT and CM (44% male, age 4-18 years, mean 11.5 years, 97% functional constipation +/- soiling, Hirschsprung's Disease). Of normal and abnormal OTT patients, 85.7% (6/7) and 18.5% (5/27) respectively had normal CM. When all markers progressed to at least the sigmoid colon, this was 100% predictive against colonic inertia. Greater than 50% of patients with manometric isolated sigmoid dysfunction had markers proximal to the recto-sigmoid.

CONCLUSION

OTT and CM are both valuable studies that assess different aspects of colonic function. OTT can be used as a screening test to rule out colonic inertia. However, the most proximal extent of remaining markers does not predict the anatomical extent of the manometric abnormality, particularly in isolated sigmoid dysfunction.

High-resolution colonic manometry and its clinical application in patients with colonic dysmotility: A review

The detailed process and mechanism of colonic motility are still unclear, and colonic motility disorders are associated with numerous clinical diseases. Colonic manometry is considered to the most direct means of evaluating colonic peristalsis. Colonic manometry has been studied for more than 30 years; however, the long duration of the examination, high risk of catheterization, huge amount of real-time data, strict catheter sterilization, and high cost of disposable equipment restrict its wide application in clinical practice. Recently, high-resolution colonic manometry (HRCM) has rapidly developed into a major technique for obtaining more effective information involved in the physiology and/or pathophysiology of colonic contractile activity in colonic dysmotility patients. This review focuses on colonic motility, manometry, operation, and motor patterns, and the clinical application of HRCM. Furthermore, the limitations, future directions, and potential usefulness of HRCM in the evaluation of clinical treatment effects are also discussed.

First translational consensus on terminology and definitions of colonic motility in animals and humans studied by manometric and other techniques

Alterations in colonic motility are implicated in the pathophysiology of bowel disorders, but high-resolution manometry of human colonic motor function has revealed that our knowledge of normal motor patterns is limited. Furthermore, various terminologies and definitions have been used to describe colonic motor patterns in children, adults and animals. An example is the distinction between the high-amplitude propagating contractions in humans and giant contractions in animals. Harmonized terminology and definitions are required that are applicable to the study of colonic motility performed by basic scientists and clinicians, as well as adult and paediatric gastroenterologists. As clinical studies increasingly require adequate animal models to develop and test new therapies, there is a need for rational use of terminology to describe those motor patterns that are equivalent between animals and humans. This Consensus Statement provides the first harmonized interpretation of commonly used terminology to describe colonic motor function and delineates possible similarities between motor patterns observed in animal models and humans in vitro (ex vivo) and in vivo. The consolidated terminology can be an impetus for new research that will considerably improve our understanding of colonic motor function and will facilitate the development and testing of new therapies for colonic motility disorders.

Long-term outcome after segmental colonic resection for slow transit constipation

PURPOSE

Colectomy with ileorectal anastomosis (IRA) is the most common surgical procedure for slow transit constipation (STC). A hemicolectomy has been suggested as an alternative to IRA with good short-term results. However, long-term results are unknown. The aim of this study was to evaluate the long-term results after hemicolectomy as a treatment for STC.

METHODS

Fifty patients with STC were selected for right- or left-sided hemicolectomy after evaluation with colonic scintigraphy from 1993 to 2008. Living patients (n = 43) received a bowel function questionnaire and a questionnaire about patient-reported outcome.

RESULTS

After a median follow-up of 19.8 years, 13 patients had undergone rescue surgery (n = 12) or used irrigation (n = 1) and were classified as failures. In all, 30 were evaluable for functional outcome and questionnaire data for 19 patients (due to 11 non-responding) could be analysed. Two reported deterioration after several years and were also classified as failures. Median stool frequency remained increased from 1 per week at baseline to 5 per week at long-term follow-up (p = 0.001). Preoperatively, all patients used laxatives, whereas 12 managed without laxatives at long-term follow-up (p = 0.002). There was some reduction in other constipation symptoms but not statically significant. In the patients' global assessment, 10 stated a very good result, seven a good result and two a poor result.

CONCLUSIONS

Hemicolectomy for STC increases stool frequency and reduces laxative use. Long-term success rate could range between 17/50 (34%) and 35/50 (70%) depending on outcome among non-responders.

Recent advances in intestinal smooth muscle research: from muscle strips and single cells, via ICC networks to whole organ physiology and assessment of human gut motor dysfunction

Gastrointestinal smooth muscle research has evolved from studies on muscle strips to spatiotemporal mapping of whole organ motor and electrical activities. Decades of research on single muscle cells and small sections of isolated musculature from animal models has given us the groundwork for interpretation of human in vivo studies. Human gut motility studies have dramatically improved by high-resolution manometry and high-resolution electrophysiology. The details that emerge from spatiotemporal mapping of high-resolution data are now of such quality that hypotheses can be generated as to the physiology (in healthy subjects) and pathophysiology (in patients) of gastrointestinal (dys) motility. Such interpretation demands understanding of the musculature as a super-network of excitable cells (neurons, smooth muscle cells, other accessory cells) and oscillatory cells (the pacemaker interstitial cells of Cajal), for which mathematical modeling becomes essential. The developing deeper understanding of gastrointestinal motility will bring us soon to a level of precision in diagnosis of dysfunction that is far beyond what is currently available.

Gastrointestinal Neuropathies: New Insights and Emerging Therapies

The bewildering complexity of the enteric nervous system makes it susceptible to develop a wide array of motility disorders, collectively called enteric neuropathies. These gastrointestinal conditions are among the most challenging to manage, mainly given poor characterization of their etiopathophysiology and outcomes. Not surprisingly, therefore, targeted or curative therapies for enteric neuropathies are lacking and management is largely symptomatic. Nonetheless, recent advances in neurogastroenterology have witnessed improvements in established strategies, such as intestinal transplantation and the emergence of new treatments including novel drugs, electrical pacing, and manipulation of fecal microbiota, as well as stem cell and gene therapy.

A new understanding of the physiology and pathophysiology of colonic motility?

BACKGROUND

In recent years, high-resolution manometry has been used in an attempt to gain a greater insight into the physiology/pathophysiology of colonic contractile activity in healthy adults and patients with colonic motility disorders. New colonic motor patterns have been identified and characterized, however, the clinical significance of these findings remains undetermined.

PURPOSE

This review will assess the current literature on colonic high-resolution manometry and determine if this procedure has advanced our understanding of colonic motility. The limitations, future directions, and the potential of this technique to assess the effects of treatment upon colonic motor patterns will also be discussed.

Usefulness of Bisacodyl Testing on Therapeutic Outcomes in Refractory Constipation

BACKGROUND

Although chronically constipated patients usually respond to medical treatment, there is a subgroup with scarce/no response, generally labeled as refractory or intractable. However, whether this lack of response is real or due to ancillary causes (suboptimal dosage, lack of compliance etc.) is unknown.

AIMS

To see whether a pharmacologic test (bisacodyl colonic intraluminal infusion during manometric assessment) may predict the therapeutic outcome.

METHODS

Data of patients undergoing 24/h colonic manometry for severe intractable constipation in whom the bisacodyl test (10 ml of drug dissolved into saline and injected through the more proximal recording port) had been carried out were retrieved and analysed, and correlations with the therapeutic outcome made.

RESULTS

Overall, charts from 38 patients (5 men) were available; of these, only 21% displayed naive high-amplitude propagated contractions (average, less than 2/24 h), mostly meal-induced, during the recordings. A bisacodyl response was present in 31.6% patients, with a mean number of events of 1.8 per patient. After bisacodyl testing, 47.3% patients underwent intensive medical treatment, 44.7% surgery (medical failures), and 8% transanal irrigation, a procedure employed to treat refractory patients. The presence of naive propulsive contractions significantly correlated with the response to bisacodyl infusion (p < 0.0001), and with a favourable outcome to intensive medical treatment (p < 0.0001).

CONCLUSIONS

The bisacodyl test may be clinically useful to better categorize constipated patients erroneously labelled as intractable and to exclude true colonic inertia, thus avoiding surgery in more than 30% of these subjects.

Use of high-resolution colonic manometry to establish etiology and direct treatment in patients with constipation: Case series with correlation to histology

BACKGROUND AND AIM

Different clinical treatments are available to treat patients with constipation. We aimed to study the etiology and direct treatment in a case series of patients with constipation by the use of high-resolution colonic manometry (HRCM).

METHODS

High-resolution colonic manometry was used to record the colorectal peristaltic contractions of the entire colon in patients. Based on the results of HRCM, 151 patients with constipation were classified into groups and received different clinical treatment such as a total or subtotal colectomy, local excision, or conservative treatment. Paraffin-embedded samples obtained after resection were studied using hematoxylin and eosin, as well as immunohistochemical staining.

RESULTS

All patients underwent HRCM over 24 h. Based on the amplitude, intensity, and trends in peristaltic contractions recorded by HRCM, we observed 117 patients with slow-transit constipation and 34 with functional outlet obstruction constipation. After an overall evaluation of the results of HRCM and anorectal function, 26, 23, 27, and 75 patients were treated with total colectomy, subtotal colectomy, local excision, and conservative treatment, respectively. Furthermore, histological examination of surgical samples showed vacuolar degeneration of nerve plexuses as well as of the muscularis propria, which also showed fibrosis in its outer layers in patients with constipation.

CONCLUSION

Different types of constipation showed different colonic motility patterns and morphological changes in the colonic wall. HRCM plays an important role in the diagnosis and classification of patients with constipation. Furthermore, HRCM can accurately identify the diseased colonic segments and help to choose the appropriate treatment.

Recent advances in understanding and managing chronic constipation

Constipation, a condition characterized by heterogeneous symptoms, is common in Western society. It is associated with reduced physical health, mental health, and social functioning. Because constipation is rarely due to a life-threatening disease (for example, colon cancer), current guidelines recommend empiric therapy. Limited surveys suggest that fewer than half of treated individuals are satisfied with treatment, perhaps because the efficacy of drugs is limited, they are associated with undesirable side effects, or they may not target the underlying pathophysiology. For example, although a substantial proportion of constipated patients have a defecatory disorder that is more appropriately treated with pelvic floor biofeedback therapy than with laxatives, virtually no pharmacological trials formally assessed for anorectal dysfunction. Recent advances in investigational tools have improved our understanding of the physiology and pathophysiology of colonic and defecatory functions. In particular, colonic and anorectal high-resolution manometry are now available. High-resolution anorectal manometry, which is increasingly used in clinical practice, at least in the United States, provides a refined assessment of anorectal pressures and may uncover structural abnormalities. Advances in our understanding of colonic molecular physiology have led to the development of new therapeutic agents (such as secretagogues, pro-kinetics, inhibitors of bile acid transporters and ion exchangers). However, because clinical trials compare these newer agents with placebo, their efficacy relative to traditional laxatives is unknown. This article reviews these physiologic, diagnostic, and therapeutic advances and focuses particularly on newer therapeutic agents.

Enteric neural stem cell therapies for enteric neuropathies

BACKGROUND

Enteric neuropathies exist as a wide range of human disorders which impact on gastrointestinal motility. Current standard therapies for enteric neuropathies are limited to surgical resection or manipulation (eg, myotomy) of affected gut segments or medical management including both therapy (eg, prokinetic pharmacotherapy) and support such as parenteral nutrition. However, such treatments often result in poor prognosis and significant morbidity. The current limitations in treatment options for enteric neuropathies underline the need for alternative approaches to treat these devastating diseases. Recent advances have highlighted the potential of enteric neural stem cells as a possible treatment option for regenerative medicine, in such cases.

PURPOSE

The purpose of this review is to provide an up-to-date synopsis of the enteric neural stem cell research field. Here, we review in detail the initial characterization of enteric neural stem cells, early preclinical studies validating their use in murine models through to the most recent findings of therapeutic rescue of diseased gut tissue. We additionally pose a number of questions regarding these recent findings which will need to be addressed prior to clinical translation of this exciting cellular therapeutic.

Characterization of Simultaneous Pressure Waves as Biomarkers for Colonic Motility Assessed by High-Resolution Colonic Manometry

Simultaneous pressure waves (SPWs) in manometry recordings of the human colon have been associated with gas expulsion. Our hypothesis was that the SPW might be a critical component of most colonic motor functions, and hence might act as a biomarker for healthy colon motility. To that end, we performed high-resolution colonic manometry (HRCM), for the first time using an 84-sensor (1 cm spaced) water-perfused catheter, in 17 healthy volunteers. Intraluminal pressure patterns were recorded during baseline, proximal and rectal balloon distention, after a meal and following proximal and rectal luminal bisacodyl administration. Quantification was performed using software, based on Image J, developed during this study. Gas expulsion was always associated with SPWs, furthermore, SPWs were associated with water or balloon expulsion. SPWs were prominently emerging at the termination of proximal high amplitude propagating pressure waves (HAPWs); we termed this motor pattern HAPW-SPWs; hence, SPWs were often not a pan-colonic event. SPWs and HAPW-SPWs were observed at baseline with SPW amplitudes of 12.0 ± 8.5 mmHg and 20.2 ± 7.2 mmHg respectively. The SPW occurrence and amplitude significantly increased in response to meal, balloon distention and luminal bisacodyl, associated with 50.3% anal sphincter relaxation at baseline, which significantly increased to 59.0% after a meal, and 69.1% after bisacodyl. Often, full relaxation was achieved. The SPWs associated with gas expulsion had a significantly higher amplitude compared to SPWs without gas expulsion. SPWs could be seen to consist of clusters of high frequency pressure waves, likely associated with a cluster of fast propagating, circular muscle contractions. SPWs were occasionally observed in a highly rhythmic pattern at 1.8 ± 1.2 cycles/min. Unlike HAPWs, the SPWs did not obliterate haustral boundaries thereby explaining how gas can be expelled while solid content can remain restrained by the haustral boundaries. In conclusion, the SPW may become a biomarker for normal gas transit, the gastrocolonic reflex and extrinsic neural reflexes. The SPW assessment reveals coordination of activities in the colon, rectum and anal sphincters. SPWs may become of diagnostic value in patients with colonic dysmotility.

Motility of the left colon in children and adolescents with functional constpation; a retrospective comparison between solid-state and water-perfused colonic manometry

BACKGROUND

Using water-perfused (WP) high-resolution manometry, we recently demonstrated that children with functional constipation (FC) lacked the postprandial increase in distal colonic cyclic motor patterns that was observed in healthy adults. Our aim was to determine if similar results could be detected using a solid-state (SS) manometry catheter.

METHODS

We performed a retrospective analysis of 19 children with FC (median age 11.1 years, 58% male) who underwent colonic manometry with a SS catheter (36 sensors, 3 cm apart). Data were compared with previously published data using a WP catheter (36 sensors, 1.5 cm apart) recorded from 18 children with FC (median age 15 years; 28% male).

KEY RESULTS

The cyclic motor patterns recorded by the SS catheter did not differ from those previously recorded by the WP catheter. There was no detected increase in this activity in response to the meal in either group. Long-single motor patterns were recorded in most patients (n = 16, 84%) with the SS catheter. The number of these events did not differ from the WP recordings. In the SS data, HAPCs were observed in 4 children prior to the meal, in 5 after the meal. This did not differ significantly from the WP data.

CONCLUSIONS & INFERENCES

These data recorded by SS manometry did not differ from WP manometry data. Regardless of the catheter used, both studies revealed an abnormal colonic response to a meal, indicating a pathology which is not related to the catheter used to record these data.

Expert consensus document: Advances in the diagnosis and classification of gastric and intestinal motility disorders

Disturbances of gastric, intestinal and colonic motor and sensory functions affect a large proportion of the population worldwide, impair quality of life and cause considerable health-care costs. Assessment of gastrointestinal motility in these patients can serve to establish diagnosis and to guide therapy. Major advances in diagnostic techniques during the past 5-10 years have led to this update about indications for and selection and performance of currently available tests. As symptoms have poor concordance with gastrointestinal motor dysfunction, clinical motility testing is indicated in patients in whom there is no evidence of causative mucosal or structural diseases such as inflammatory or malignant disease. Transit tests using radiopaque markers, scintigraphy, breath tests and wireless motility capsules are noninvasive. Other tests of gastrointestinal contractility or sensation usually require intubation, typically represent second-line investigations limited to patients with severe symptoms and are performed at only specialized centres. This Consensus Statement details recommended tests as well as useful clinical alternatives for investigation of gastric, small bowel and colonic motility. The article provides recommendations on how to classify gastrointestinal motor disorders on the basis of test results and describes how test results guide treatment decisions.

Diagnostic Tests in Pediatric Constipation

Constipation is one of the most common gastrointestinal symptoms in children. With a median reported prevalence of 12%, it accounts for about 25% of all pediatric gastroenterology consultations. The majority of children experiences functional constipation and do not usually require any diagnostic testing. For those children not responding to conventional medical treatment or in the presence of a more significant clinical picture, however, an accurate instrumental assessment is usually recommended to evaluate either the underlying pathophysiologic mechanisms or a possible organic etiology. The present review analyzes the possible diagnostic investigations for severely constipated children, focusing on their actual indications and their utility in clinical practice. During the last decade, there has been a remarkable increase in our knowledge of normal and abnormal colonic and anorectal motility in children, and a number of different techniques to measure transit and motility have been developed and are discussed in this narrative review.

Duhamel operation for children with distal colonic dysmotility

PURPOSE

To report outcomes of children with constipation refractory to medical management and manometrically proven distal colonic dysmotility, managed with rectosigmoidectomy followed by Duhamel operation (Duhamel).

METHODS

Children who underwent a Duhamel from 2009 onwards for intractable constipation and left colonic dysmotility were retrospectively reviewed. The primary end point was resolution of constipation, and secondary end point was postoperative complications. Continuous data were median (range).

RESULTS

11 patients (4 males) had Duhamel at 11 years (5-16) with constipation started from 2 years (1-8). Hirschsprung's disease was excluded. All Duhamels were performed with a covering ileostomy: 9 following a Hartmann procedure, one following a previously failed reversal of Hartmann, and one Duhamel performed with a pre-existing ileostomy. All ileostomies were subsequently closed. Median resection length was 22 cm (11-31). Length of stay was 8 days (5-23). Follow-up was 5 years (0.5-7). Age at final review was 15 years (10-18). Resolution of constipation occurred in nine patients (4 required antegrade continence enemas (ACE), 5 with laxative); two had persistent constipation and faecal incontinence despite ACE, ultimately requiring an ileostomy. Two postoperative small bowel obstructions required laparotomy.

CONCLUSION

Duhamel performed in children with manometrically proven distal colonic dysmotility yielded 82% resolution of refractory constipation; half of them subsequently needed ACE.

Transplantation of enteric nervous system stem cells rescues nitric oxide synthase deficient mouse colon

Enteric nervous system neuropathy causes a wide range of severe gut motility disorders. Cell replacement of lost neurons using enteric neural stem cells (ENSC) is a possible therapy for these life-limiting disorders. Here we show rescue of gut motility after ENSC transplantation in a mouse model of human enteric neuropathy, the neuronal nitric oxide synthase (nNOS^−/−) deficient mouse model, which displays slow transit in the colon. We further show that transplantation of ENSC into the colon rescues impaired colonic motility with formation of extensive networks of transplanted cells, including the development of nNOS⁺ neurons and subsequent restoration of nitrergic responses. Moreover, post-transplantation non-cell-autonomous mechanisms restore the numbers of interstitial cells of Cajal that are reduced in the nNOS^−/− colon. These results provide the first direct evidence that ENSC transplantation can modulate the enteric neuromuscular syncytium to restore function, at the organ level, in a dysmotile gastrointestinal disease model.

Isolated human and mouse enteric nervous system stem cells (ENSCs) are capable of integrating and promoting innervation of the mouse colon. Here the authors show that transplantation of mouse ENSCs into a mouse model of human enteric neuropathy restores colon motility.

Established and emerging methods for assessment of small and large intestinal motility

BACKGROUND

Gastrointestinal symptoms are common in the general population and may originate from disturbances in gut motility. However, fundamental mechanistic understanding of motility remains inadequate, especially of the less accessible regions of the small bowel and colon. Hence, refinement and validation of objective methods to evaluate motility of the whole gut is important. Such techniques may be applied in clinical settings as diagnostic tools, in research to elucidate underlying mechanisms of diseases, and to evaluate how the gut responds to various drugs. A wide array of such methods exists; however, a limited number are used universally due to drawbacks like radiation exposure, lack of standardization, and difficulties interpreting data. In recent years, several new methods such as the 3D-Transit system and magnetic resonance imaging assessments on small bowel and colonic motility have emerged, with the advantages that they are less invasive, use no radiation, and provide much more detailed information.

PURPOSE

This review outlines well-established and emerging methods to evaluate small bowel and colonic motility in clinical settings and in research. The latter include the 3D-Transit system, magnetic resonance imaging assessments, and high-resolution manometry. Procedures, indications, and the relative strengths and weaknesses of each method are summarized.

Prospective evaluation of same day versus next day colon manometry results in children with medical refractory constipation

BACKGROUND

We evaluated the change in colon manometry (CM) parameters and interpretation comparing results when the study is performed the same day after the motility catheter is placed under anesthesia or the following day.

METHODS

CM catheter was placed with colonoscopy under anesthesia and recorded on day 1 and repeated on day 2. Study parameters including motility index during fasting, post-prandial and post-Bisacodyl challenge phase; gastrocolonic response; number, presence and propagation of high amplitude propagating contractions (HAPCs); and, study interpretation were compared between both the days.

KEY RESULTS

Motility index (fasting, post-Bisacodyl phase, P<.05), HAPC number (10.1 vs 6.6, P=.01) and the proportion of patients having HAPCs (92% vs 70%, P=.002) was significantly higher on day 2 vs day 1. HAPC propagation improved on day 2 vs day 1 (fully propagated, 49% vs 37%; partially propagated, 43% vs 33%; absent 8% vs 30%). Study interpretation changed from day 1 to day 2. On day 1, 37% had a normal study and 63% had an abnormal study. On day 2, all patients with a normal study on day 1 remained normal, and patients with an abnormal study on day 1, 53% remained abnormal and 47% had a normal study.

CONCLUSIONS & INFERENCES

CM parameters are affected the day the catheter is placed with colonoscopy under anesthesia. The number, presence, and propagation of HAPCs were significantly higher/improved on day 2 compared to day 1. Overall, CM interpretation changed from abnormal to normal from day 1 to day 2 in 47% of the patients.

Recording In Vivo Human Colonic Motility: What Have We Learnt Over the Past 100 Years?

To understand the abnormalities that underpin functional gut disorders we must first gain insight into the normal patterns of gut motility. While detailed information continually builds on the motor patterns (and mechanisms that control them) of the human esophagus and anorectum, our knowledge of normal and abnormal motility in the more inaccessible regions of the gut remains poor. This particularly true of the human colon. Investigation of in vivo colonic motor patterns is achieved through measures of transit (radiology, scintigraphy and, more recently, "smart pills") or by direct real-time recording of colonic contractility (intraluminal manometry). This short review will provide an overview of findings from the past and present and attempt to piece together the complex nature of colonic motor patterns. In doing so it will build a profile of human colonic motility and determine the likely mechanisms that control this motility.

Motility Disorders in Children

Gastrointestinal motility disorders in the pediatric population are common and can range from benign processes to more serious disorders. Performing and interpreting motility evaluations in children present unique challenges. There are primary motility disorders but abnormal motility may be secondary due to other disease processes. Diagnostic studies include radiographic scintigraphic and manometry studies. Although recent advances in the genetics, biology, and technical aspects are having an important impact and have allowed for a better understanding of the pathophysiology and therapy for gastrointestinal motility disorders in children, further research is needed to be done to have better understanding of the pathophysiology and for better therapies.

Pediatric enteric neuropathies: diagnosis and current management

PURPOSE OF REVIEW

Neurointestinal diseases are increasingly recognized as causes of significant gastrointestinal morbidity in children. This review highlights the most common pediatric enteric neuropathies and their diagnosis and management, emphasizing insights and discoveries from the most recent literature available.

RECENT FINDINGS

The embryologic and histopathologic causes of enteric neuropathies are varied. They range from congenital aganglionosis in Hirschsprung disease, to autoimmune-mediated loss of neuronal subtypes in esophageal achalasia and Chagas disease, to degenerative neuropathies in some cases of chronic intestinal pseudo-obstruction and gastroparesis. Increased awareness of the clinical presentation and diagnostic evaluation of these conditions is essential as it allows for earlier initiation of treatment and improved outcomes. Most current therapies, which include medical management, neurostimulation, and operative intervention, aim to minimize the symptoms caused by these conditions. The evidence base for many of these treatments in children is poor, and multiinstitutional prospective studies are needed. An innovative therapy on the horizon involves using neuronal stem cell transplantation to treat the underlying disorder by replacing the missing or damaged neurons in these diseases.

SUMMARY

Although recent advances in basic and clinical neurogastroenterology have significantly improved our awareness and understanding of enteric neuropathies, the efficacy of current treatment approaches is limited. The development of novel therapies, including pharmacologic modulators of neurointestinal function, neurostimulation to enhance gut motility, and neuronal cell-based therapies, is essential to improve the long-term outcomes in children with these disorders.

High-resolution anatomic correlation of cyclic motor patterns in the human colon: Evidence of a rectosigmoid brake

Colonic cyclic motor patterns (CMPs) have been hypothesized to act as a brake to limit rectal filling. However, the spatiotemporal profile of CMPs, including anatomic origins and distributions, remains unclear. This study characterized colonic CMPs using high-resolution (HR) manometry (72 sensors, 1-cm resolution) and their relationship with proximal antegrade propagating events. Nine healthy volunteers were recruited. Recordings were performed over 4 h, with a 700-kcal meal given after 2 h. Propagating events were visually identified and analyzed by pattern, origin, amplitude, extent of propagation, velocity, and duration. Manometric data were normalized using anatomic landmarks identified on abdominal radiographs. These were mapped over a three-dimensional anatomic model. CMPs comprised a majority of detected propagating events. Most occurred postprandially and were retrograde propagating events (84.9 ± 26.0 retrograde vs. 14.3 ± 11.8 antegrade events/2 h, P = 0.004). The dominant sites of initiation for retrograde CMPs were in the rectosigmoid region, with patterns proximally propagating by a mean distance of 12.4 ± 0.3 cm. There were significant differences in the characteristics of CMPs depending on the direction of travel and site of initiation. Association analysis showed that proximal antegrade propagating events occurred independently of CMPs. This study accurately characterized CMPs with anatomic correlation. CMPs were unlikely to be triggered by proximal antegrade propagating events in our study context. However, the distal origin and prominence of retrograde CMPs could still act as a mechanism to limit rectal filling and support the theory of a "rectosigmoid brake."NEW & NOTEWORTHY Retrograde cyclic motor patterns (CMPs) are the dominant motor patterns in a healthy prepared human colon. The major sites of initiation are in the rectosigmoid region, with retrograde propagation, supporting the idea of a "rectosigmoid brake." A significant increase in the number of CMPs is seen after a meal. In our study context, the majority of CMPs occurred independent of proximal propagating events, suggesting that CMPs are primarily controlled by external innervation.

Pan-Colonic Pressurizations Associated With Relaxation of the Anal Sphincter in Health and Disease: A New Colonic Motor Pattern Identified Using High-Resolution Manometry

OBJECTIVES

Only a few studies have applied high-resolution manometry (HRM) to the study of colonic motility in adults and none of them have concurrently evaluated colonic and anal motor activity. The aim of the study was to evaluate colonic and anal motor activity by means of HRM in healthy subjects. As the present study revealed the presence of a new colonic motor pattern (pan-colonic pressurizations) in healthy subjects, three additional studies were conducted: the first and the second to exclude that this motor event results from an artifact due to abdominal wall contraction and to confirm its modulation by cholinergic stimulation, and the third, as pilot study, to test the hypothesis that this colonic pattern is defective in patients with chronic constipation refractory to current pharmacological treatments.

METHODS

In both volunteers and patients the HRM catheter was advanced proximally during colonoscopy.

RESULTS

In all subjects, pressure increases of 15±3 mm Hg and 24±4 s simultaneously occurring in all colonic sensors (pan-colonic pressurizations) and associated with anal sphincter relaxation were identified. Subjects had 85±38 pan-colonic pressurizations, which increased significantly during meal (P=0.007) and decreased afterward (P=0.01), and were correlated with feelings of and desire to evacuate gas. The mean number of propagating sequences was 47±39, and only retrograde increased significantly postprandially (P=0.01). Pan-colonic pressurizations differed from strain artifacts and significantly increased after prostigmine. In patients pan-colonic pressurizations were significantly reduced as compared with volunteers.

CONCLUSIONS

Pan-colonic pressurizations associated with relaxations of the anal sphincter represent a new colonic motor pattern that seems to be defective in patients with treatment-refractory chronic constipation and may have a role in the transport of colonic gas and in the facilitation of the propagating sequence-induced colonic transport.

Intraluminal pressure patterns in the human colon assessed by high-resolution manometry

Assessment of colonic motor dysfunction is rarely done because of inadequate methodology and lack of knowledge about normal motor patterns. Here we report on elucidation of intraluminal pressure patterns using High Resolution Colonic Manometry during a baseline period and in response to a meal, in 15 patients with constipation, chronically dependent on laxatives, 5 healthy volunteers and 9 patients with minor, transient, IBS-like symptoms but no sign of constipation. Simultaneous pressure waves (SPWs) were the most prominent propulsive motor pattern, associated with gas expulsion and anal sphincter relaxation, inferred to be associated with fast propagating contractions. Isolated pressure transients occurred in most sensors, ranging in amplitude from 5–230 mmHg. Rhythmic haustral boundary pressure transients occurred at sensors about 4–5 cm apart. Synchronized haustral pressure waves, covering 3–5 cm of the colon occurred to create a characteristic intrahaustral cyclic motor pattern at 3–6 cycles/min, propagating in mixed direction. This activity abruptly alternated with erratic patterns resembling the segmentation motor pattern of the small intestine. High amplitude propagating pressure waves (HAPWs) were too rare to contribute to function assessment in most subjects. Most patients, dependent on laxatives for defecation, were able to generate normal motor patterns in response to a meal.

Transanal Irrigation in the Treatment of Children With Intractable Functional Constipation

OBJECTIVES

The aim of the study was to assess the treatment efficacy of transanal irrigation and parental satisfaction in children with intractable functional constipation (FC) treated with Peristeen.

METHODS

Cross-sectional survey study among parents of children (age 0-18 years) treated with Peristeen for FC (based on the Rome III criteria). Anonymous questionnaires were sent out to parents via mail, these consisted of 25 self-developed, multiple-choice questions regarding the use of Peristeen, current gastrointestinal symptoms, adverse effects of Peristeen, concomitant medication use, and parental satisfaction.

RESULTS

Out of 91 invited families, 67 (74%) returned the questionnaire. In total, 84% of patients experienced fecal incontinence prior to treatment. Out of all children who still used Peristeen at the time of survey (n = 49), fecal incontinence had resolved completely in 41%, 12% experienced occasional episodes of fecal incontinence (<1 episode per week) and the remaining 47% still experienced episodes of fecal incontinence regularly (≥1 time per week). A total of 28 children (42%) experienced pain during rectal irrigation, especially during insertion of the catheter, inflating the balloon, or during irrigation. Overall, 86% of the parents were satisfied with the result of transanal irrigation and 67% reported that they would continue using transanal irrigation for the treatment of their child's symptoms.

CONCLUSIONS

Transanal irrigation may be effective in the treatment of children with FC and renders a high parental satisfaction. Future prospective studies, preferably RCTs, are necessary to further evaluate this treatment option.

Sequential incremental doses of bisacodyl increase the diagnostic accuracy of colonic manometry

BACKGROUND

Colonic manometry is the standard diagnostic modality for evaluating colonic motility in children. Intraluminal bisacodyl is routinely used to trigger high-amplitude propagating contractions (HAPCs), a feature of normal colonic motility. Usually, only a single dose (0.2 mg/kg) is suggested. We retrospectively explored whether the use of an additional higher (0.4 mg/kg) dose of bisacodyl increases the yield of colonic manometry.

METHODS

In 103 children (median age: 8.8 years, range 3.2-15.7 years) with a diagnosis of slow transit constipation, colonic motility was recorded for 1 h before and 1 h after each of two incremental doses of bisacodyl (low, L, dose: 0.2 mg/kg, max 10 mg; high, H, dose: 0.4 mg/kg, max 20 mg) and the characteristics of HAPCs analyzed.

KEY RESULTS

High-amplitude propagating contractions were seen in 85 children. H dose significantly increased the proportion of patients with fully propagated HAPCs (H dose: 57/103 [55%], L dose: 27/103 [26%], p < 0.001), paralleling the significant decrease in the proportion with partially propagated HAPCs (H dose: 29/103 [28%], L dose: 47/103 [46%], p < 0.01). Mean HAPC number significantly increased throughout the colon at H compared to L dose (7.2 ± 5.05 vs 5.6 ± 5.1, p < 0.05). Finally, the proportion of patients with normal pressure wave morphology of HAPCs significantly increased with higher dose (H dose: 55/85 [65%], L dose: 27/85 [32%], p < 0.001).

CONCLUSIONS & INTERFERENCES

An additional higher dose of bisacodyl during colonic manometry improves colonic neuromuscular function suggesting its use might improve interpretation and decision making in children with slow transit constipation.