Human Bowel Research Articles

Measurement of hepatic insulin sensitivity early after the bypass of the proximal small bowel in humans.

SummaryObjectiveUnlike gastric banding or sleeve gastrectomy procedures, intestinal bypass procedures, Roux‐en‐Y gastric bypass in particular, lead to rapid improvements in glycaemia early after surgery. The bypass of the proximal small bowel may have weight loss and even caloric restriction‐independent glucose‐lowering properties on hepatic insulin sensitivity. In this first human mechanistic study, we examined this hypothesis by investigating the early effects of the duodeno‐jejunal bypass liner (DJBL; GI Dynamics, USA) on the hepatic insulin sensitivity by using the gold standard euglycaemic hyperinsulinaemic clamp methodology.MethodSeven patients with obesity underwent measurement of hepatic insulin sensitivity at baseline, 1 week after a low‐calorie liquid diet and after a further 1 week following insertion of the DJBL whilst on the same diet.ResultsDuodeno‐jejunal bypass liner did not improve the insulin sensitivity of hepatic glucose production beyond the improvements achieved with caloric restriction.ConclusionsCaloric restriction may be the predominant driver of early increases in hepatic insulin sensitivity after the endoscopic bypass of the proximal small bowel. The same mechanism may be at play after Roux‐en‐Y gastric bypass and explain, at least in part, the rapid improvements in glycaemia.

Mechanosensitive ion channel Piezo2 is important for enterochromaffin cell response to mechanical forces.

The gastrointestinal epithelial enterochromaffin (EC) cell synthesizes the vast majority of the body's serotonin. As a specialized mechanosensor, the EC cell releases this serotonin in response to mechanical forces. However, the molecular mechanism of EC cell mechanotransduction is unknown. In the present study, we show, for the first time, that the mechanosensitive ion channel Piezo2 is specifically expressed by the human and mouse EC cells. Activation of Piezo2 by mechanical forces results in a characteristic ionic current, the release of serotonin and stimulation of gastrointestinal secretion. Piezo2 inhibition by drugs or molecular knockdown decreases mechanosensitive currents, serotonin release and downstream physiological effects. The results of the present study suggest that the mechanosensitive ion channel Piezo2 is specifically expressed by the EC cells of the human and mouse small bowel and that it is important for EC cell mechanotransduction. The enterochromaffin (EC) cell in the gastrointestinal (GI) epithelium is the source of nearly all systemic serotonin (5-hydroxytryptamine; 5-HT), which is an important neurotransmitter and endocrine, autocrine and paracrine hormone. The EC cell is a specialized mechanosensor, and it is well known that it releases 5-HT in response to mechanical forces. However, the EC cell mechanotransduction mechanism is unknown. The present study aimed to determine whether Piezo2 is involved in EC cell mechanosensation. Piezo2 mRNA was expressed in human jejunum and mouse mucosa from all segments of the small bowel. Piezo2 immunoreactivity localized specifically within EC cells of human and mouse small bowel epithelium. The EC cell model released 5-HT in response to stretch, and had Piezo2 mRNA and protein, as well as a mechanically-sensitive inward non-selective cation current characteristic of Piezo2. Both inward currents and 5-HT release were inhibited by Piezo2 small interfering RNA and antagonists (Gd3+ and D-GsMTx4). Jejunum mucosal pressure increased 5-HT release and short-circuit current via submucosal 5-HT3 and 5-HT4 receptors. Pressure-induced secretion was inhibited by the mechanosensitive ion channel antagonists gadolinium, ruthenium red and D-GsMTx4. We conclude that the EC cells in the human and mouse small bowel GI epithelium selectively express the mechanosensitive ion channel Piezo2, and also that activation of Piezo2 by force leads to inward currents, 5-HT release and an increase in mucosal secretion. Therefore, Piezo2 is critical to EC cell mechanosensitivity and downstream physiological effects.

In vivo transplantation of fetal human gut-derived enteric neural crest cells.

The prospect of using neural cell replacement for the treatment of severe enteric neuropathies has seen significant progress in the last decade. The ability to harvest and transplant enteric neural crest cells (ENCCs) that functionally integrate within recipient intestine has recently been confirmed by in vivo murine studies. Although similar cells can be harvested from human fetal and postnatal gut, no studies have as yet verified their functional viability upon in vivo transplantation. We sought to determine whether ENCCs harvested from human fetal bowel are capable of engraftment and functional integration within recipient intestine following in vivo transplantation into postnatal murine colon. Enteric neural crest cells selected and harvested from fetal human gut using the neurotrophin receptor p75NTR were lentivirally labeled with either GFP or calcium‐sensitive GCaMP and transplanted into the hindgut of Rag2 − /γc − /C5 −‐immunodeficient mice at postnatal day 21. Transplanted intestines were assessed immunohistochemically for engraftment and differentiation of donor cells. Functional viability and integration with host neuromusculature was assessed using calcium imaging. Transplanted human fetal gut‐derived ENCC showed engraftment within the recipient postnatal colon in 8/15 mice (53.3%). At 4 weeks posttransplantation, donor cells had spread from the site of transplantation and extended projections over distances of 1.2 ± 0.6 mm (n = 5), and differentiated into enteric nervous system (ENS) appropriate neurons and glia. These cells formed branching networks located with the myenteric plexus. Calcium transients (change in intensity F/F0 = 1.25 ± 0.03; 15 cells) were recorded in transplanted cells upon stimulation of the recipient endogenous ENS demonstrating their viability and establishment of functional connections.

Targeted delivery of short-chain fatty acids to the human large bowel

Targeted delivery of short-chain fatty acids to the human large bowel

Interplay between mast cells, enterochromaffin cells, and sensory signaling in the aging human bowel

BackgroundAdvanced age is associated with a reduction in clinical visceral pain perception. However, the underlying mechanisms remain largely unknown. Previous studies have suggested that an abnormal interplay between mast cells, enterochromaffin (EC) cells, and afferent nerves contribute to nociception in gastrointestinal disorders. The aim of this study was to investigate how aging affects afferent sensitivity and neuro‐immune association in the human bowel.MethodsMechanical and chemical sensitivity of human bowel afferents were examined by ex vivo afferent nerve recordings. Age‐related changes in the density of mast cells, EC cells, sensory nerve terminals, and mast cell‐nerve micro‐anatomical association were investigated by histological and immune staining.Key ResultsHuman afferents could be broadly classified into subpopulations displaying mechanical and chemical sensitivity, adaptation, chemo‐sensitization, and recruitment. Interestingly human bowel afferent nerve sensitivity was attenuated with age. The density of substance P‐immunoreactive (SP‐IR) nerve varicosities was also reduced with age. In contrast, the density of ileal and colonic mucosal mast cells was increased with age, as was ileal EC cell number. An increased proportion of mast cells was found in close apposition to SP‐IR nerves.Conclusions & InferencesAfferent sensitivity in human bowel was reduced with advancing age. Augmentation of mast cells and EC cell numbers and the mast cell‐nerve association suggest a compensatory mechanism for sensory neurodegeneration.

Dientamoeba fragilis, the Neglected Trichomonad of the Human Bowel.

Dientamoeba fragilis is a protozoan parasite of the human bowel, commonly reported throughout the world in association with gastrointestinal symptoms. Despite its initial discovery over 100 years ago, arguably, we know less about this peculiar organism than any other pathogenic or potentially pathogenic protozoan that infects humans. The details of its life cycle and mode of transmission are not completely known, and its potential as a human pathogen is debated within the scientific community. Recently, several major advances have been made with respect to this organism's life cycle and molecular biology. While many questions remain unanswered, these and other recent advances have given rise to some intriguing new leads, which will pave the way for future research. This review encompasses a large body of knowledge generated on various aspects of D. fragilis over the last century, together with an update on the most recent developments. This includes an update on the latest diagnostic techniques and treatments, the clinical aspects of dientamoebiasis, the development of an animal model, the description of a D. fragilis cyst stage, and the sequencing of the first D. fragilis transcriptome.

Intestinal Manometry Force Sensor for Robotic Capsule Endoscopy: An Acute, Multipatient In vivo Animal and Human Study.

Development of a new medical device class generally termed robotic capsule endoscopes (RCE) is currently being pursued by multiple research groups. These maneuverable devices will allow minimally invasive diagnosis and treatment of intestinal pathologies. While the intraluminal pressures related to the migrating motor complex (MMC) are well understood, no previous study has measured the active contact forces exerted by the human small bowel wall on a solid, or near solid bolus such as an RCE. Understanding and quantifying the active contact force are critical for the advancement of RCE technology. In this study, the authors develop a novel manometric contact force sensor for human studies and validate the feasibility of the design, sterilization method, and minimally invasive surgical procedure in a multianimal study, followed by a multihuman study. Four porcine tests of the sensor were conducted. The mean porcine myenteric contact force measured using the new sensor is 1.20 ± 0.08N·cm-1. The mean myenteric contact force recorded for all five human test subjects is 0.18 ± 0.33N·cm-1. This study demonstrates the feasibility of operating an MMC force sensor in a live human with a minimally invasive surgical technique and presents force data necessary for RCE design. This study represents the first known myenteric contact force measurements on a solid bolus in the human small intestine.

Human Gut Bacteroidetes

The human large bowel is colonized by a community of microbes, the microbiota, which has a significant impact on human health and nutrition through the production of short chain fatty acids (SCFAs), and by interaction with the host immune system. The major nutrients available to these organisms are dietary glycans, also known as complex carbohydrates. Thus, dietary and nutraceutical strategies, based on complex carbohydrates, can, potentially, be deployed to encourage the dominance of beneficial microbes in the microbiota, particularly those producing health promoting SCFAs such as propionate and butyrate, and bacteria that have an anti‐inflammatory impact through its interaction with the human immune system, ensuring that this microbial ecosystem has a positive influence on human health. This approach, however, is greatly restricted by a critical lack of understanding of the mechanisms by which complex glycans are metabolized by the microbiota. Significantly, the wealth of genomic and metagenomic microbiota sequence presents an exciting, but so far unfulfilled, opportunity to make decisive advances in our understanding of glycan metabolism in the human large bowel. This seminar will review our biochemical, genetic and microbiological strategies, in harness with metagenomic and genomic data, to understand the mechanisms of complex glycans utilization by the human microbiota1,2,3. The models established, will trigger the development of novel dietary strategies that are designed to maximize human health through manipulation of microbiota structure.

Changes of excitatory and inhibitory neurotransmitters in the colon of rats underwent to the wrap partial restraint stress.

Animal models proposed to reproduce some of the human irritable bowel syndrome (IBS) symptoms are based on the hypothesis that psychosocial stressors play a pivotal role in the IBS etio-pathology. We investigated the wrap restraint stress (WRS) model with the aim to analyze the morphological changes of the entire colonic wall of these animals that showed some of the human IBS symptoms such as visceral hypersensitivity. Male Wistar rats were used and WRS was maintained for 2 h. Abdominal contractions (AC) were recorded in the colon-rectum by balloon distension. Fecal pellets were quantitated. Colonic specimens were examined by routine histology, immunohistochemistry and western blot. WRS animals were characterized by: (i) increase in AC number and fecal pellets mean weight; (ii) clusters of mononucleated cells, increase in eosinophilic granulocytes and mast cells in the mucosa; (iii) increase in CGRP-immunoreactive (IR) nerve fibers in the lamina propria; (iv) decrease in myenteric NK1r-IR and nNOS-IR neurons and in submucous nNOS-IR neurons; (v) decrease in SP-IR nerve fibers in the muscle wall; (vi) reduction in S100β-IR glia in the entire colonic wall; (vii) increase in CRF1r-IR myenteric neurons; (viii) no change in ChAT-IR neurons, smooth muscle cells and interstitial cells of Cajal. The present results support the consistency of the WRS as a potential model where part of the human IBS signs and symptoms are reproduced. The changes in glial cells and in excitatory and inhibitory neurotransmitters might represent the substrate for the dysmotility and hypersensitivity.

Sidestream dark field imaging of the serosal microcirculation during gastrointestinal surgery.

The study aimed to describe the serosal microcirculation of the human bowel using sidestream dark field imaging, a microscopic technique using polarized light to visualize erythrocytes through capillaries. We also compared its feasibility to the current practice of sublingual microcirculatory assessment. In 17 patients sidestream dark field measurements were performed during gastrointestinal surgery. Microcirculatory parameters like microvascular flow index (MFI), proportion of perfused vessels (PPV), perfused vessel density (PVD) and total vessel density (TVD) were determined for every patient, sublingually and on the bowel serosa. Sixty measurements were done on the bowel of which eight (13%) were excluded, five owing to too much bowel peristalsis and three because of pressure artefacts. Image stability was in favour of sublingual measurements [pixel loss per image, bowel 145 (95% CI 126-164) vs sublingual 55 (95% CI 41-68); P < 0.001] and time to acquire a stable image [bowel 96 s (95% CI 63-129) vs. sublingual 46 s (95% CI 29-64); P = 0.013]. No difference in the MFI was observed [bowel 2.9 (interquartile range 2.87-2.95) vs sublingual 3.0 (interquartile range 2.91-3.0); P = 0.081]. There was a difference in the PPV [bowel 95% (95% CI 94-96) vs sublingual 97% (95% CI 97-99); P < 0.001], PVD [bowel 12.9 mm/mm2 (95% CI 11.1-14.8) vs sublingual 17.4 mm/mm2 (95% CI 15.6-19.1); P = 0.003] and the TVD [bowel 13.6 mm/mm2 (95% CI 11.6-15.6) vs sublingual 17.7 mm/mm2 (95% CI 16.0-19.4); P = 0.008]. Sidestream dark field imaging is a very promising technique for bowel microcirculatory visualization and assessment. It is comparable to sublingual assessment and the analysis produces a similar outcome with slightly differing anatomical features.

Effects of heat-killed Lactobacillus kunkeei YB38 on human intestinal environment and bowel movement: a pilot study.

It is well known that lactic acid bacteria supplementation is beneficial for intestinal conditions such as microbiota; however, the effects of killed-lactic acid bacteria on intestinal conditions are largely unclear. This study aimed to evaluate the effect of heat-killed Lactobacillus kunkeei YB38 (YB38) at a dose of approximately 10 mg/day on human intestinal environment and bowel movement. This single-blind study enrolled 29 female subjects with a low defecation frequency who consumed heat-killed YB38 at four increasing dosage levels: 0 (placebo), 2, 10, and 50 mg. Each dose was consumed daily for two weeks, with a two-week baseline period preceding the dosing-period and a two-week washout period ending the study. Observed levels of Bacteroides fragilis group significantly decreased with intake of heat-killed YB38 at ≥10 mg/day compared with levels during placebo intake (P<0.01). Faecal pH significantly decreased with 10 and 50 mg/day intake (P<0.01 and 0.05, respectively). Acetic acid levels tended to increase in faeces at the 50 mg/day dose (P<0.1). Bowel movement tended to increase in all heat-killed YB38 intake periods (P<0.1). In conclusion, heat-killed YB38 altered human intestinal microbiota at doses of ≥10 mg/day and tended to increase bowel movement at ≥2 mg/day. This is the first study to show the intestinal microbiota-altering effect of L. kunkeei and to report the bowel movement-improving effect of heat-killed lactic acid bacteria.

Dissimilatory sulfate reduction in the intestinal sulfate-reducing bacteria

The study of the intestinal sulfate-reducing bacteria, the process of dissimilatory sulfate reduction and accumulation of hydrogen sulfide, as well as their role in the inflammatory bowel diseases, including ulcerative colitis, in animals and human have increa­singly attracted the attention of scientists. New opportunities for studying inflammatory bowel disease and the assessment of the effectiveness of its treatment is an urgent problem of modern biology and medicine. In this review, brief characteristics of these bacteria and their mechanism of dissimilatory sulfate reduction were described based on modern literature data and own research. The characteristics of substrates for intestinal sulfate-reducing bacteria and the thermodynamic properties of their electron donors were also described. Special attention was paid to the mechanism and stages of sulfate dissimilation including role of enzymes involved in this process. Based on our results, general scheme of dissimilatory sulfate reduction sho­wing the activity of each enzyme of the process was demonstrated. The described physiological and biochemical parameters are important for a more detailed understanding of sulfate dissimilation in the human and animal bowel, as well as studying the mechanisms of action of the antimicrobial prophylactics and the therapy against specific components involved in the pathogenesis of the disease. It is also essential for understanding the mechanisms of bowel diseases and for evaluating the effectiveness of its therapy.

Incidental finding of meckel's diverticulum in a patient with ascaris-induced intestinal obstruction

Ascaris lumbricoides is a large parasite that infests the human bowel, especially in regions with poor environmental sanitation in the tropics. Meckel's diverticulum is mainly an asymptomatic congenital intestinal anomaly. Rarely, it becomes symptomatic when it is associated with complications such as diverticulitis, perforation, and bleeding. It may be associated with a heavy worm load. We report a case of 7-year-old female child with intestinal obstruction and incidental finding of Meckel's diverticulum with gangrenous bowel.

Enterocyte Damage: A Piece in the Puzzle of Post-Cardiac Arrest Syndrome.

Cardiac arrest is considered to be a cause of small bowel ischemia, but the consequences of cardiac arrest on the human small bowel have been rarely studied. Plasma citrulline concentration is a marker of functional enterocyte mass, and plasma intestinal fatty acid-binding protein (I-FABP) concentration is a marker of enterocyte damage. We aimed to measure enterocyte biomarkers after cardiac arrest and to study the prognostic value of biomarker abnormalities. This is a prospective, observational, single-center study of patients admitted to the intensive care unit (ICU) for cardiac arrest, evaluating plasma citrulline and I-FABP concentrations at admission and after 24 h and variables according to the Utstein criteria. Variables according to 28-day Cerebral Performance Category score of 1 to 2 (good neurological outcome) versus 3 to 5 (poor neurological outcome) were compared. Sixty-nine patients with cardiac arrest of both cardiac and hypoxic origin were included. At ICU admission, plasma citrulline concentration was low in 65% and plasma I-FABP was elevated in 82% of the patients. After 24 h, plasma citrulline was low in 82% and I-FABP was normal in 60% of the patients. Patients with a poor neurological outcome had a lower plasma citrulline concentration and a higher I-FABP concentration at ICU admission. By multivariate analysis, plasma citrulline levels of 13.1 μmol L or less and I-FABP more than 260 pg mL were independently associated with a poor neurological outcome (odds ratio, 21.9 [2.2-215], and odds ratio, 13.6 [1.4-129], respectively). Cardiac arrest resuscitation is associated with evidence of small bowel mucosal damage in most patients, with a short and intense I-FABP elevation at admission and a decrease in citrulline concentration during the first day. In this study, low plasma citrulline and high I-FABP concentrations at ICU admission were predictive of a poor neurological outcome. This study confirms that cardiac arrest is a model of small bowel mucosal ischemia and suggests that enterocyte damage is a piece in the puzzle of post-cardiac arrest syndrome.

Rho-kinase expression in Hirschsprung's disease.

Rho-kinase (ROCK) is the primary effector protein in the RhoA pathway, which regulates Ca(2+)-independent smooth muscle contraction in the human bowel. This pathway has been reported to be hyper-activated in the aganglionic bowel of EDNRB-null (-/-) rats compared to the ganglionic bowel from EDNRB (+/+) rats. We hypothesised that ROCK expression is up-regulated in human aganglionic bowel and designed this study to investigate ROCK 1 and ROCK 2 expression in Hirschsprung's disease (HSCR) and controls. Full-length specimens were collected following pull-through surgery for HSCR (n=9). Colonic controls (n=6) were obtained during colostomy closure from patients with anorectal malformations. Distribution of ROCK 1/2 expression was evaluated using double-labelled immunofluorescence and confocal microscopy. ROCK1/2 protein expression was assessed in mucosa and tunica muscularis using western blot analysis. There was strong expression of both ROCK 1 and ROCK 2 in interstitial cells of Cajal (ICCs) and ganglia. ROCK 1 expression was reduced in aganglionic bowel compared to HSCR ganglionic bowel and controls in both mucosa and tunica muscularis. ROCK 2 expression was similar in the colon of children with HSCR and controls. This is the first report of strong ROCK expression in colonic ICCs. Although the rat model of aganglionic bowel suggests that Ca(2+)-independent smooth muscle contraction involving ROCK is hyper-activated, our data indicate ROCK 1 expression is decreased in aganglionic bowel and ROCK 2 expression is unaltered in children with HSCR.

The Transcriptome Sequence of Dientamoeba fragilis Offers New Biological Insights on its Metabolism, Kinome, Degradome and Potential Mechanisms of Pathogenicity

Dientamoeba fragilis is a human bowel parasite with a worldwide distribution. Dientamoeba was once described as a rare and harmless commensal though recent reports suggest it is common and potentially pathogenic. Molecular data on Dientamoeba is scarce which limits our understanding of this parasite. To address this, sequencing of the Dientamoeba transcriptome was performed. Messenger RNA was extracted from cultured Dientamoeba trophozoites originating from clinical stool specimens, and sequenced using Roche GS FLX and Illumina HiSeq technologies. In total 6,595 Dientamoeba transcripts were identified. These sequences were analysed using the BLAST2GO software suite and via BLAST comparisons to sequences available from TrichDB, GenBank, MEROPS and kinase.com. Several novel KEGG pathway maps were generated and gene ontology analysis was also performed. These results are thoroughly discussed guided by knowledge available for other related protozoa. Attention is paid to the novel biological insights afforded by this data including peptidases and kinases of Dientamoeba, as well as its metabolism, novel chemotherapeutics and possible mechanisms of pathogenicity. Currently, this work represents the largest contribution to our understanding of Dientamoeba molecular biology and also represents a major contribution to our understanding of the trichomonads generally, many of which are important pathogens of humans and animals.

Effect of growth factors, estradiol 17-β, and short chain fatty acids on the intestinal HT29-MTX cells : Growth factors and SCFAs effects on intestinal E12 cells.

Peptides growth factors, hormones, and short chain fatty acids (SCFAs) are constantly in contact with the human bowel when secreted by gland or ingested by food, as milk and colostrum, or, as in the case of SCFAs, produced by fermentation processes. This study considers the effect of growth factors, estradiol 17-β, and SCFAs on the metabolic activity and proliferation of undifferentiated HT29-MTX-E12 (E12) cells. In particular, the aim of the present study was the characterization of the human intestinal cell line E12 for its suitability as an in vitro intestinal model for cell-nutrient interaction studies. The effect of insulin-like growth factors (IGF)-I, epidermal growth factors (EGF), transforming growth factor alpha (TGF-α), transforming growth factor beta (TGF-β), estradiol 17-β and butyrate, propionate, and acetate was assessed on metabolic activity and proliferation of E12 cells using AlamarBlue(TM) assay and PicoGreen® assay, respectively. IGF-I and estradiol 17-β significantly (P < 0.05; P < 0.001) increased both metabolic activity and proliferation in a concentration-dependent manner, whereas TGF-α, at the concentration of 1ng/mL, significantly (P < 0.05) reduced the metabolic activity of the cells. Further, a dose-dependent inhibition of cell metabolic activity was detected in the presence of all SCFAs tested. Butyrate showed to be the most active in the inhibition of E12 metabolic activity and its effect was enhanced by the presence of propionate and acetate. E12 cells, in undifferentiated state, showed to be a suitable in vitro model for cell-nutrient interaction studies, providing an opportunity to examine the potential role of growth factors, hormones and SCFAs in the regulation of the intestinal cell viability.

Heat shock protein 60 levels in tissue and circulating exosomes in human large bowel cancer before and after ablative surgery.

Heat shock protein 60 (Hsp60) is a chaperonin involved in tumorigenesis, but its participation in tumor development and progression is not well understood and its value as a tumor biomarker has not been fully elucidated. In the current study, the authors presented evidence supporting the theory that Hsp60 has potential as a biomarker as well as a therapeutic target in patients with large bowel cancer. The authors studied a population of 97 subjects, including patients and controls. Immunomorphology, Western blot analysis, and quantitative real-time polymerase chain reaction were performed on tissue specimens. Exosomes were isolated from blood and characterized by electron microscopy, biochemical tests, and Western blot analysis. Hsp60 was found to be increased in cancerous tissue, in which it was localized in the tumor cell plasma membrane, and in the interstitium associated with cells of the immune system, in which it was associated with exosomes liberated by tumor cells and, as such, circulated in the blood. An interesting finding was that these parameters returned to normal shortly after tumor removal. The data from the current study suggested that Hsp60 is a good candidate for theranostics applied to patients with large bowel carcinoma and encourage similar research among patients with other tumors in which Hsp60 has been implicated.

Endocuff-assisted colonoscopy increases polyp detection rate: a simulated randomized study involving an anatomic colorectal model and 32 international endoscopists.

The undetected colonic lesions behind the folds and flexures are a major factor contributing to the adenoma miss rate. To assess the efficacy of Endocuff, a special attachment was fixed at the distal tip of a colonoscope, for the polyp detection. This soft accessory is composed of a plastic cap surrounded by flexible finger-like projections on the lateral sides of the cap that make holding of the folds during scope withdrawal easier. This was a simulated pilot study with one anatomic colorectal model, containing 13 polyps positioned in obvious locations and behind the folds. Thirty-two endoscopists (16 Japanese and 16 foreign visitors) with different levels of experience performed examinations on the model in a randomized order by using Endocuff-assisted colonoscopy (EAC) and standard colonoscope (SC). To assess the detection rate of polyps and the feasibility of Endocuff insertion. EAC detected significantly more polyps than SC with 9.9 versus 7.5 mean lesions (p = 0.03), respectively, comparing the 16 first colonoscopies in each group. Endocuff was useful independent of the level of experience of the participants. After crossover, EAC in second position allowed an additional detection of 1.8 polyps compared with SC (p = 0.001). After adjustment on experience, time of detection, and order of colonoscopy, EAC over-detected 1.2 polyps (p = 0.0037). The insertion time (p = 0.99) was identical. There was no difference in the mean time of polyp detection between EAC and SC groups (p = 0.520). This was not a clinical study. The stiffness of the folds in the colonic model was higher than in the human large bowel. EAC was associated with a higher polyp detection rate. Even in such relatively stiff anatomic model, it was easier to spread out the colonic mucosa between the folds using this cap. This study provides an additional argument for the routine application of this easy-to-use accessory to improve polyp detection.

418 Quantifying the Phase II Motor Patterns of the Human Small Bowel Migrating Motor Complex Using High Resolution Fiber Optic Manometry

418 Quantifying the Phase II Motor Patterns of the Human Small Bowel Migrating Motor Complex Using High Resolution Fiber Optic Manometry