Effect of meal composition and sham feeding on duodenojejunal motility in humans

Efficacy and safety of therapeutic means for postoperative ileus: an umbrella review of meta-analyses

BACKGROUND & AIMS

Postoperative ileus is treated using a large number of methods with variable efficacy. This study further clarifies the advantages and disadvantages of existing treatments through umbrella evaluation.

METHOD

This study conducted a systematic search of databases to select and include meta-analyses discussing the treatment of postoperative ileus. We recalculated the estimated values, 95% confidence intervals, heterogeneity estimates, small study effects, excessive significance tests, and publication biases for each included study using both random and fixed effect models.

RESULTS

A total of 24 meta-analyses, including 27 treatment protocols, were reviewed in this study. Among them, chewing gum, coffee, ERAS(Enhanced Recovery After Surgery) protocols, acupuncture, opioid receptor antagonists, Da-Cheng-Qi-Tang, early enteral nutrition, and Zusanli point injection therapy have been shown to significantly improve postoperative ileus (Class II). Opioid receptor antagonists, early enteral nutrition, ERAS, and chewing gum have also been found to significantly reduce the postoperative hospital stay (Class II).

CONCLUSION

Eight treatment options can effectively reduce postoperative ileus, while the effectiveness and safety of other treatment options for postoperative ileus require further confirmation through high-quality research.

Effect of chewing gum in bowel preparation for patients undergoing small bowel and colon capsule endoscopy: Systematic review with meta-analysis

Background and study aims Quality of bowel preparation and successful transit are critical factors for complete small bowel capsule endoscopy (SBCE) and colon capsule endoscopy (CCE). The aim of this systematic review with meta-analysis was to assess the impact of chewing gum as part of the bowel preparation regimen on the completion rate in both SBCE and CCE. Methods A systematic literature search was conducted in PubMed, Cochrane, Web of Science and Embase. Data were extracted upon quality assessment of included studies. Two reviewers conducted the screening process according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Eighty-four studies met the search criteria and four randomized controlled trials were included in the meta-analysis, these were assessed for bias using Minors. Pooled completion rate of SBCE studies was defined as the primary outcome. Results Three randomized controlled trials were SBCE studies and one was a CCE study. The pooled completion rate (91%) was not significantly higher in SBCE patients who were given chewing gum after capsule ingestion compared to those who were not (85%). Variance information was not reported in all studies, and therefore, pooled transit time estimates could not be calculated. Conclusions Chewing gum has a good safety profile but has only been used as a booster in one CCE study and a few SBCE studies. More prospective randomized controlled trials, therefore, are needed to investigate the efficacy of chewing gum for achieving complete capsule examination.

Effectiveness of Chewing Gum on Nausea and Vomiting Following Postprocedure: A Systematic Review and Meta-Analysis

PURPOSE

This study aimed to evaluate the effectiveness of chewing gum in reducing postprocedure nausea and vomiting.

DESIGN

A systematic review and meta-analysis.

METHODS

A systematic literature search was performed on MEDLINE Complete, EMBASE, CINAHL, PubMed, Web of Science, Academic Search Complete, and Cochrane Library databases from their inception to October 2, 2022. Methodological quality was assessed using the revised Cochrane Risk of Bias 2.0 tool for randomized trials. A meta-analysis was performed using a fixed-effects model to calculate pooled effects with Review Manager 5.4.1.

FINDINGS

Twelve randomized trials encompassing 1,458 participants were pooled. The chewing gum intervention was effective in reducing vomiting (P = .007; risk ratio = 0.55; 95% Cl = 0.35-0.85), but not nausea (P = .14; risk ratio = 0.84; 95% Cl = 0.66-1.06). Thirty-minute sessions of gum chewing were significantly more effective in reducing vomiting than 15-minute sessions (P = .04; risk ratio = 0.31; 95% Cl = 0.1-0.93).

CONCLUSIONS

The results indicate that repeated gum chewing sessions of at least 30 minutes may act as a nonpharmacological intervention for reducing vomiting. However, further studies are necessary to determine the outcomes of chewing gum interventions.

Effects of Postoperative Gum Chewing on Recovery of Gastrointestinal Function Following Laparoscopic Gynecologic Surgery: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Chewing gum, considered a form of sham feeding, has been shown to improve intestinal motor and secretory function in various types of abdominal surgery. We conducted this systematic review to evaluate the effects of postoperative gum chewing on the recovery of gastrointestinal function after laparoscopic gynecologic surgery. Methods: We performed a comprehensive literature review of all randomized controlled trials (RCTs) in PubMed, Embase, and a reference list of relevant studies from the inception to 11 March 2024, comparing postoperative gum chewing versus no gum chewing following laparoscopic gynecologic surgery regardless of indications and setting without language restriction. The primary outcome was the time to the presence of bowel sounds and the time to the first passage of flatus. Cochrane's risk of bias tool was used to assess the risk of bias in included studies. Results: Nine RCTs with a total of 1011 patients were included. Overall, three studies were categorized as having a low risk of bias, three had some concerns, and three exhibited a high risk of bias. The time to the presence of bowel sounds (mean difference [MD] -2.66 h, 95% confidence interval [CI] -3.68 to -1.64, p < 0.00001) and time to the first passage of flatus (MD -4.20 h, 95% CI -5.79 to -2.61, p < 0.00001) was significantly shorter in the gum-chewing group. There was no statistical difference between the two groups with regard to the time to the first defecation (MD -6.52 h, 95% CI -15.70 to 2.66, p = 0.16), time to the first postoperative mobilization (MD 24.05 min, 95% CI -38.16 to 86.26, p = 0.45), postoperative ileus (MD 0.68, 95% CI 0.39 to 1.19, p = 0.17), and length of hospital stay (MD -0.05 day, 95% CI -0.14 to 0.04, p = 0.28). Conclusions: Gum chewing following laparoscopic gynecologic surgery appears to promote the recovery of gastrointestinal function, as evidenced by a reduced time to the presence of bowel sounds and the first passage of flatus.

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.

The impact of chewing gum on postoperative bowel activity and postoperative pain after total laparoscopic hysterectomy

We aimed to investigate the effects of chewing gum on bowel activity and postoperative pain in patients undergoing laparoscopic hysterectomy. Patients were randomised into two groups (n = 58, study; n = 51, control). In the study group, patients started chewing sugarless gum every 2 h for 15 min, beginning at the second postoperative hour. The control group did not chew gum, and they received standard postoperative care. Both groups were compared primarily in terms of the amount of time until the first bowel movement, the time of the first passage of flatus and the time of first defaecation. The amount of time until the first bowel movement, the time of the first passage of flatus and the time of the first defaecation were found to be significantly shorter in the chewing gum group (p < .001). The amount of postoperative analgesics that were needed and VAS scores at 6-hours and 24-hours postoperatively, were found to be lower in the study group than in the control group (p < .001). Chewing gum was found to have beneficial effects on bowel motility and postoperative pain in patients undergoing laparoscopic hysterectomy. This affordable and simple method could be recommended to patients after total laparoscopic hysterectomy.Impact statementWhat is already known on this subject? Postoperative gastrointestinal dysfunction remains a source of morbidity and the major determinant of length of stay after abdominal operation. The mechanism of enhanced recovery from postoperative gastrointestinal dysfunction with the help of chewing gum is believed to be the cephalic-vagal stimulation of digestion which increases the promotability of neural and humoral factors that act on different parts of the gastrointestinal tract.What do the results of this study add? The findings of previous randomised controlled studies have been inconsistent regarding the effect of chewing gum on postoperative bowel function following abdominal gynecological surgery. In this randomised prospective study, we found that chewing gum early in the postoperative period after total laparoscopic hysterectomy hastened time to bowel motility and flatus. To our knowledge this is the first study of the impact of chewing gum on bowel motility after total laparoscopic hysterectomy.What are the implications of these findings for clinical practice and/or further research? Chewing gum early in the postoperative period following laparoscopic hysterectomy hastens time to bowel motility and flatus. The use of chewing gum is a simple and cheap strategy for promoting the recovery of gastrointestinal functions.

Relationship between MRI quantified small bowel motility and abdominal symptoms in Crohn's disease patients-a validation study

OBJECTIVE

Previous single-centre MRI data suggests an inverse correlation between normal small bowel motility variance and abdominal symptoms in Crohn's disease (CD) patients. The current work prospectively assesses this observation in a larger, two-centre study.

METHODS

MR enterography datasets were analysed from 82 patients (38 male, aged 16-68), who completed a contemporaneous Harvey-Bradshaw index (HBI) questionnaire. Dynamic "cine motility" breath-hold balanced steady-state free precession sequences were acquired through the whole small bowel (SB) volume. Regions of interest (ROIs) were manually applied to encompass all morphologically normal SB (i.e. excluding Crohn's affected bowel) and a validated registration technique used to produce motility maps. Mean and variance motility metrics were correlated with HBI and symptom components (well-being, pain and diarrhoea) using Spearman's correlation statistics.

RESULTS

Overall, motility variance was non-significantly negatively correlated with the total HBI score, (r = -0.17, p = 0.12), but for subjects with a HBI score over 10, the negative correlation was significant (r = -0.633, p = 0.027). Motility variance was negatively correlated with diarrhoea (r = -0.29, p < 0.01). No significant correlation was found between mean motility and HBI (r = -0.02, p = 0.84).

CONCLUSION

An inverse association between morphologically normal small bowel motility variance and patient symptoms has been prospectively confirmed in patients with HBI scores above 10. This association is particularly apparent for the symptom of diarrhoea. Advances in knowledge: This study builds on preliminary work by confirming in a large, well-controlled prospective multicentre study a relationship between normal bowel motility variance and patient reported symptoms which may have implications for drug development and clinical management.

Multicentre randomized clinical trial of the effect of chewing gum after abdominal surgery

Background

Postoperative ileus is a common complication of abdominal surgery, leading to patient discomfort, morbidity and prolonged postoperative length of hospital stay (LOS). Previous studies suggested that chewing gum stimulates bowel function after abdominal surgery, but were underpowered to evaluate its effect on LOS and did not include enhanced recovery after surgery (ERAS)-based perioperative care. This study evaluated whether chewing gum after elective abdominal surgery reduces LOS and time to bowel recovery in the setting of ERAS-based perioperative care.

Methods

A multicentre RCT was performed of patients over 18 years of age undergoing abdominal surgery in 12 hospitals. Standard postoperative care (control group) was compared with chewing gum three times a day for 30 min in addition to standard postoperative care. Randomization was computer-generated; allocation was concealed. The primary outcome was postoperative LOS. Secondary outcomes were time to bowel recovery and 30-day complications.

Results

Between 2011 to 2015, 1000 patients were assigned to chewing gum and 1000 to the control arm. Median LOS did not differ: 7 days in both arms (P = 0·364). Neither was any difference found in time to flatus (24 h in control group versus 23 h with chewing gum; P = 0·873) or time to defaecation (60 versus 52 h respectively; P = 0·562). The rate of 30-day complications was not significantly different either.

Conclusion

The addition of chewing gum to an ERAS postoperative care pathway after elective abdominal surgery does not reduce the LOS, time to bowel recovery or the rate of postoperative complications. Registration number: NTR2594 (Netherlands Trial Register).

Sham Feeding with Bacon Does Not Alter Transit Time or Complete Examination Rate During Small Bowel Capsule Endoscopy

BACKGROUND

During capsule endoscopy (CE) studies, the complete examination rate (CER) can be increased by prolonging capsule battery life or reducing gastric transit time (GTT) and/or small bowel transit time (SBTT). However, despite enhanced battery life, 10% of studies remain incomplete. Previously studied interventions to reduce SBTT and enhance CER have produced conflicting results. We hypothesize that this may be a consequence of an insufficiently potent stimulus of small bowel motility.

AIMS

To examine whether potent stimulation of the cephalic response of digestion during small bowel CE reduces GTT and/or SBTT and thus increases the CER.

METHODS

A single-blind randomized trial was performed to evaluate the effect of bacon sham feeding on GTT, SBTT and CER.

RESULTS

Baseline characteristics were similar between 63 sham fed patients and 59 controls. The median GTT was 17 min (9-65) in the bacon group and 25 min (14-55) in the control group. The median SBTT was 199 min (119-316) and 222 min (151-287), respectively. Cox proportional hazards model demonstrated no significant difference between groups for GTT (rate ratio 1.03, 95% CI 0.71-1.51, P = 0.87) or SBTT (rate ratio 1.02, 95% CI 0.70-1.49, P = 0.93). Although the taste of bacon was considered favorably by 72% of participants, taste did not correlate with GTT (ρ = 0.03, P = 0.83) or SBTT (ρ = - 0.115, P = 0.33). The CER was 91 and 95% in the bacon and control groups, respectively (P = 0.35).

CONCLUSION

Bacon sham feeding has no effect on GTT, SBTT or CER and cannot be recommended in clinical practice.

Chewing Gum for Intestinal Function Recovery after Colorectal Cancer Surgery: A Systematic Review and Meta-Analysis

Background

This meta-analysis was performed to assess the efficacy and safety of chewing gum in intestinal function recovery after colorectal cancer surgery.

Methods

A systematic search was conducted in PubMed, Embase, Science Direct, and Cochrane library for relevant randomized controlled trials (RCTs) published until April 2017. Summary risk ratios or weighted mean differences with 95% confidence intervals were used for continuous and dichotomous outcomes, respectively.

Results

17 RCTs with a total number of 1845 patients were included. Gum chewing following colorectal cancer surgery significantly reduced the time to first passage of flatus (WMD −0.55; 95% CI −0.94 to −0.16; P = 0.006), first bowel movement (WMD −0.60; 95% CI −0.87 to −0.33; P < 0.0001), start feeding (WMD −1.32; 95% CI −2.18 to −0.46; P = 0.003), and the length of postoperative hospital stay (WMD −0.88; 95% CI −1.59 to −0.17; P = 0.01), but no obvious differences were found in postoperative nausea, vomiting, abdominal distention, pneumonia, and mortality, which were consistent with the findings of intention to treat analysis.

Conclusions

Chewing gum could accelerate the recovery of intestinal function after colorectal cancer surgery. However, it confers no advantage in postoperative clinical complications. Further large-scale and high-quality RCTs should be conducted to confirm these results.

Importance of the enteric nervous system in the control of the migrating motility complex

The migrating motility complex (MMC), a cyclical phenomenon, represents rudimentary motility pattern in the gastrointestinal tract. The MMC is observed mostly in the stomach and gut of man and numerous animal species. It contains three or four phases, while its phase III is the most characteristic. The mechanisms controlling the pattern are unclear in part, although the neural control of the MMC seems crucial. The main goal of this article was to discuss the importance of intrinsic innervation of the gastrointestinal tract in MMC initiation, migration, and cessation to emphasize that various MMC-controlling mechanisms act through the enteric nervous system. Two main neural regions, central and peripheral, are able to initiate the MMC. However, central regulation of the MMC may require cooperation with the enteric nervous system. When central mechanisms are not active, the MMC can be initiated peripherally in any region of the small bowel. The enteric nervous system affects the MMC in response to the luminal stimuli which can contribute to the initiation and cessation of the cycle, and it may evoke irregular phasic contractions within the pattern. The hormonal regulators released from the endocrine cells may exert a modulatory effect upon the MMC mostly through the enteric nervous system. Their central action could also be considered. It can be concluded that the enteric nervous system is involved in the great majority of the MMC-controlling mechanisms.

Effect of gum chewing on ameliorating ileus following colorectal surgery: A meta-analysis of 18 randomized controlled trials

BACKGROUND AND OBJECTIVE

Chewing gum, as an alternative to sham feeding, had been shown to hasten the recovery of gut function following abdominal surgery. However, conclusions remained contradictory. We sought to conduct an updated meta-analysis to evaluate the efficacy of gum chewing in alleviating ileus following colorectal surgery.

METHODS

We searched PubMed, EMBASE, and Cochrane Library Databases through February 2017 to identify randomized controlled trials (RCTs) evaluating the efficacy of the additional use of chewing gum following colorectal surgery. After screening for inclusion, data extraction, and quality assessment, meta-analysis was conducted by the Review Manager 5.3 software. The outcomes of interest were the time to first flatus, time to first bowel movement, length of hospital stay, and some clinically relevant parameters. We also performed subgroup analyses according to the type of surgical approaches or on trials that adopted enhanced recovery after surgery (ERAS) protocol or sugared gum.

RESULTS

A total of 18 RCTs, involving 1736 patients, were included. Compared with standardized postoperative care, Chewing gum resulted in a shorter passage to first flatus [WMD = -8.81, 95%CI: (-13.45, -4.17), P = 0.0002], earlier recovery of bowel movement [WMD = -16.43, 95%CI: (-22.68, -10.19), P < 0.00001], and a reduction in length of hospital stay [WMD = -0.89, 95%CI: (-1.72, -0.07), P = 0.03]. Chewing gum was also associated with a lower risk of postoperative ileus [OR = 0.41, 95%CI: (0.23, 0.73), P = 0.003]. No evidence of significant advantages in overall postoperative complication, nausea, vomiting, bloating, readmission and reoperation towards the addition of chewing gum was observed. Subgroup analyses all favored gum chewing. However, the findings are hampered by the significant heterogeneity between trials.

CONCLUSIONS

Based on current evidence, chewing gum offers an inexpensive, well-tolerated, safe and effective method to ameliorate ileus following colorectal surgery. However, tightly controlled, randomized and considerably larger multicenter trials are warranted to further validate our findings.

Impact of gum chewing on the quality of bowel preparation for colonoscopy: an endoscopist-blinded, randomized controlled trial

BACKGROUND AND AIMS

Gum chewing can accelerate motility in the GI tract; clinical studies suggested gum chewing can reduce postoperative ileus. However, no trial has investigated the effect of gum chewing on bowel preparation for colonoscopy in addition to polyethylene glycol (PEG). The objective of this study was to investigate whether gum chewing before colonoscopy can increase the quality of bowel preparation.

METHODS

This was a single-center, randomized controlled trial. Consecutive patients undergoing colonoscopy were randomized to the gum group or the control group. Patients in the gum group chewed sugar-free gum every 2 hours for 20 minutes each time from the end of drinking 2 L of PEG to the beginning of colonoscopy. Patients in the control group only received 2 L of PEG before colonoscopy. The quality of bowel preparation, procedure time, adenoma detection rate, patients' tolerance, and adverse events were compared.

RESULTS

Three hundred patients were included in the study (150 in the control group, 150 in the gum group). More than 90% of patients in both groups were satisfied with the process of bowel preparation, and the incidence of adverse events was comparable in the 2 groups (41.3% vs 46.0%, P = .42). The mean Boston Bowel Preparation Scale score was 6.2 ± 1.4 and 6.1 ± 1.2 in the control group and the gum group, respectively, and the difference between the 2 groups was not significant (P = .51).

CONCLUSIONS

This study indicates that gum chewing does not improve the quality of bowel preparation for colonoscopy, but it can improve patients' satisfaction with the process of bowel preparation and does not have negative effects on cleanliness. (Clinical trials registration number: NCT02507037.).

Chewing gum for enhancing early recovery of bowel function after caesarean section

BACKGROUND

Caesarean sections (CS) are the most frequent major surgery in the world. A transient impairment of bowel motility is expected after CS. Although this usually resolves spontaneously within a few days, it can cause considerable discomfort, require symptomatic medication and delay hospital discharge, thus increasing costs. Chewing gum in the immediate postoperative period is a simple intervention that may be effective in enhancing recovery of bowel function in other types of abdominal surgeries.

OBJECTIVES

To assess the effects of chewing gum to reduce the duration of postoperative ileus and to enhance postoperative recovery after a CS.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (20 June 2016), LILACs (20 June 2016), ClinicalTrials.gov (20 June 2016), WHO International Clinical Trials Registry Platform (ICTRP) (20 June 2016) and the reference lists of retrieved studies.

SELECTION CRITERIA

All randomised controlled trials comparing chewing gum versus usual care, for women in the first 24 hours after a CS. We included studies published in abstract form only.Quasi-randomised, cross-over or cluster-randomised trials were not eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies for inclusion, extracted data and assessed the risk of bias following standard Cochrane methods. We present dichotomous outcome results as risk ratio (RR) with 95% confidence intervals (CI) and continuous outcome results as mean differences (MD) and 95% CI. We pooled the results of similar studies using a random-effects model in case of important heterogeneity. We used the GRADE approach to assess the overall quality of evidence.

MAIN RESULTS

We included 17 randomised trials (3149 participants) conducted in nine different countries. Seven studies (1325 women) recruited exclusively women undergoing elective CS and five studies (833 women) only included women having a primary CS. Ten studies (1731 women) used conventional feeding protocols (nil by mouth until the return of intestinal function). The gum-chewing regimen varied among studies, in relation to its initiation (immediately after CS, up to 12 hours later), duration of each session (from 15 to 60 minutes) and number of sessions per day (three to more than six). All the studies were classified as having a high risk of bias due to the nature of the intervention, women could not be blinded and most of the outcomes were self-reported.Primary outcomes of this review: for the women that chewed gum, the time to passage of first flatus was seven hours shorter than those women in the 'usual care' control group (MD -7.09 hours, 95% CI -9.27 to -4.91 hours; 2399 women; 13 studies; random-effects Tau² = 14.63, I² = 95%, very low-quality evidence). This effect was consistent in all subgroup analyses (primary and repeat CS, time spent chewing gum per day, early and conventional feeding protocols, elective and non-elective CS and time after CS when gum-chewing was initiated). The rate of ileus was on average over 60% lower in the chewing-gum group compared to the control (RR 0.39, 95% CI 0.19 to 0.80; 1139 participants; four studies; I² = 39%, low-quality evidence). Tolerance to gum-chewing appeared to be high. Three women in one study complained about the chewing gum (but no further information was provided) and none of the studies reported adverse effects (eight studies, 925 women, low-quality evidence).Secondary outcomes of this review: the time to passage of faeces occurred on average nine hours earlier in the intervention group (MD -9.22 hours, 95% CI -11.49 to -6.95 hours; 2016 participants; 11 studies; random-effects Tau² = 12.53, I² = 93%, very low-quality evidence). The average duration of hospital stay was shorter in the intervention compared to the control group (MD -0.36 days, 95% CI -0.53 to -0.18 days; 1489 participants; seven studies; random-effects Tau² = 0.04, I² = 92%). The first intestinal sounds were heard earlier in the intervention than in the control group (MD -4.56 hours, 95% CI -6.18 to -2.93 hours; 1729 participants; nine studies; random-effects Tau² = 5.41, I² = 96%). None of the studies assessed women's satisfaction in relation to having to chew gum. The need for analgesia or antiemetic agents did not differ between the intervention and control groups (average RR 0.50, 95% CI 0.12 to 2.13; 726 participants; three studies; random-effects Tau² = 0.79, I² = 69%).

AUTHORS' CONCLUSIONS

This review found 17 randomised controlled trials (involving 3149 women). We downgraded the quality of the evidence for time to first passage of flatus and of faeces and for adverse effects/intolerance to gum chewing because of the high risk of bias of the studies (due to lack of blinding and self-report). For time to first flatus and faeces, we downgraded the quality of the evidence further because of the high heterogeneity in these meta-analyses and the potential for publication bias based on the visual inspection of the funnel plots. The quality of the evidence for adverse effects/tolerance to gum chewing and for ileus was downgraded because of the small number of events. The quality of the evidence for ileus was further downgraded due to the unclear risk of bias for the assessors evaluating this outcome.The available evidence suggests that gum chewing in the immediate postoperative period after a CS is a well tolerated intervention that enhances early recovery of bowel function. However the overall quality of the evidence is very low to low.Further research is necessary to establish the optimal regimen of gum-chewing (initiation, number and duration of sessions per day) to enhance bowel function recovery and to assess potential adverse effects of and women's satisfaction with this intervention. New studies also need to assess the compliance of the participants to the recommended gum-chewing instructions. Future large, well designed and conducted studies, with better methodological and reporting quality, will help to inform future updates of this review and enhance the body of evidence for this intervention.

Aberrant Motility in Unaffected Small Bowel is Linked to Inflammatory Burden and Patient Symptoms in Crohn's Disease

BACKGROUND

Inflammation-related enteric dysmotility has been postulated as a cause for abdominal symptoms in Crohn's disease (CD). We investigated the relationship between magnetic resonance imaging-quantified small bowel (SB) motility, inflammatory activity, and patient symptom burden.

METHODS

The Harvey-Bradshaw index (HBI) and fecal calprotectin were prospectively measured in 53 patients with CD (median age, 35; range, 18-78 years) the day before magnetic resonance enterography, which included a dynamic (cine), breath-hold motility sequence, repeated to encompass the whole SB volume. A validated registration-based motility quantitation technique produced motility maps, and regions of interest were drawn to include all morphologically normal SB (i.e., excluding diseased bowel). Global SB motility was correlated with calprotectin, HBI, and symptom components (well-being, pain, and diarrhea). Adjustment for age, sex, smoking, and surgical history was made using multivariate linear regression.

RESULTS

Median calprotectin was 336 (range, 0-1280). Median HBI, motility mean, and motility variance were 3 (range, 0-16), 0.33 (0.18-0.51), and 0.01 (0.0014-0.034), respectively. Motility variance was significantly negatively correlated with calprotectin (rho = -0.33, P = 0.015), total HBI (rho = -0.45, P < 0.001), well-being (rho = -0.4, P = 0.003), pain (rho = -0.27, P = 0.05), and diarrhea (rho = -0.4, P = 0.0025). The associations remained highly significant after adjusting for covariates. There was no association between mean motility and calprotectin or HBI (P > 0.05).

CONCLUSIONS

Reduced motility variance in morphologically normal SB is associated with patient symptoms and fecal calprotectin levels, supporting the hypothesis that inflammation-related enteric dysmotility may explain refractory abdominal symptoms in CD.

The Use of Chewing Gum Postoperatively in Pediatric Scoliosis Patients Facilitates an Earlier Return to Normal Bowel Function

PURPOSE

In surgical correction of scoliosis in pediatric patients, gastrointestinal complications including postoperative ileus can result in extended hospital stays, poorer pain management, slower progression with physical therapy, and overall decreased patient satisfaction. In patients undergoing gastrointestinal, gynecological, and urological surgery, gum chewing has been shown to reduce time to flatus and passage of feces. The authors hypothesized that chewing gum could also speed return to normal bowel function in pediatric patients undergoing surgical correction of scoliosis.

METHODS

The researchers obtained institutional review board approval for a prospective, randomized, controlled trial. Eligible patients included all adolescent idiopathic scoliosis patients undergoing posterior spinal fusion. Exclusion criteria included previous gastrointestinal surgery or preexisting gastrointestinal disease. Patients were randomized by coin flip. The treatment group chewed sugar-free bubble gum 5 times a day for 20 to 30 minutes beginning on postoperative day 1; the control group did not chew gum. Patients were asked a series of questions regarding subjective gastrointestinal symptoms each day. Time to flatus and first passage of feces were recorded as indicators of return to normal bowel function. Normality of data was assessed using normal probability plots.

RESULTS

A total of 83 patients completed the study (69 females and 14 males; mean age, 14.4 years). Of the 42 patients in the chewing gum group, 8 elected to stop chewing gum regularly before discharge for to a variety of reasons. Patients who chewed gum experienced first bowel movement on average 145.9 hours after surgery, 30.9 hours before those who did not chew gum (p = .04). Gum-chewing patients first experienced flatus an average of 55.2 hours after surgery, compared with 62.3 hours for controls. This trend did not reach statistical significance (p = .12). No difference was noted in duration of hospital stay, medications administered as required, or subjective symptoms.

CONCLUSION

Chewing gum after posterior spinal fusion for scoliosis is safe and may speed return of normal bowel function. Chewing gum after surgical correction of scoliosis facilitates an earlier return to normal bowel function, which may improve patient satisfaction in the early postoperative period.

Motility patterns of ex vivo intestine segments depend on perfusion mode

AIM: To evaluate and characterize motility patterns from small intestinal gut segments depending on different perfusion media and pressures.

METHODS: Experiments were carried out in a custom designed perfusion chamber system to validate and standardise the perfusion technique used. The perfusion chamber was built with a transparent front wall allowing for optical motility recordings and a custom made fastener to hold the intestinal segments. Experiments with different perfusion and storage media combined with different luminal pressures were carried out to evaluate the effects on rat small intestine motility. Software tools which enable the visualization and characterization of intestinal motility in response to different stimuli were used to evaluate the videotaped experiments. The data collected was presented in so called heatmaps thus providing a concise overview of form and strength of contractility patterns. Furthermore, the effect of different storage media on tissue quality was evaluated. Haematoxylin-Eosin stainings were used to compare tissue quality depending on storage and perfusion mode.

RESULTS: Intestinal motility is characterized by different repetitive motility patterns, depending on the actual situation of the gut. Different motility patterns could be recorded and characterized depending on the perfusion pressure and media used. We were able to describe at least three different repetitive patterns of intestinal motility in vitro. Patterns with an oral, anal and oro-anal propagation direction could be recorded. Each type of pattern finalized its movement with or without a subsequent distension of the wavefront. Motility patterns could clearly be distinguished in heatmap diagrams. Furthermore undirected motility could be observed. The quantity of the different patterns varies and is highly dependent on the perfusion medium used. Tissue preservation varies depending on the perfusion medium utilized, therefore media with a simple composition as Tyrode solution can only be recommended for short time experiments. The more complex media, MEM-HEPES medium and especially AQIX^® RS-I tissue preservation reagent preserved the tissue much better during perfusion.

CONCLUSION: Perfusion media have to be carefully chosen considering type and duration of the experiments. If excellent tissue quality is required, complex media are favorable. Perfusion pressure is also of great importance due to the fact that a minimum amount of luminal pressure seems to be necessary to trigger intestinal contractions.

Facilitating return of bowel function after colorectal surgery: alvimopan and gum chewing

Postoperative ileus is common after colorectal surgery, and has a huge impact on hospital LOS. With the impeding cost crisis in the United States, safely reducing length of stay is essential. Chewing gum and pharmacological treatment with alvimopan are safe, simple tools to reduce postoperative ileus and its associated costs. Future research will determine if integrating these tools with laparoscopic procedures and enhanced recovery pathways is a best practice in colorectal surgery.

Mechanisms and effects of "fat taste" in humans

Evidence supporting a "taste" cue from fat in the oral cavity continues to accrue. The proposed stimuli for fat taste, non-esterified fatty acids (NEFA), are released from food through hydrolytic rancidity and lipase activity derived from foods or saliva. NEFA must then be released from the food matrix, negotiate the aqueous environment to reach taste cell surfaces, and interact with receptors such as CD36 and GPR120 or diffuse across cell membranes to initiate a taste signal. Knowledge of these processes in non-gustatory tissues should inform understanding of taste responses to NEFA. Additionally, downstream effects of oral triglyceride exposure have been observed in numerous studies. Data specific to effects of NEFA versus triglyceride are scarce, but modified sham feeding trials with triglyceride document cephalic phase responses including elevations in serum lipids and insulin as well as potential, but debated, effects on gut peptides, appetite, and thermogenesis. In this review, we highlight the mechanisms by which NEFA migrate to and interact with taste cells, and then we examine physiological responses to oral fat exposure.

Effect of gum chewing on the recovery from laparoscopic colorectal cancer surgery

Purpose

We aimed to examine the effect of gum chewing after laparoscopic colorectal cancer surgery.

Methods

We reviewed the medical records of patients who underwent laparoscopic colorectal cancer surgery in Incheon St. Mary's Hospital, The Catholic University of Korea School of Medicine. We divided the patients into 2 groups: group A consisted of 67 patients who did not chew gum; group B consisted of 65 patients who chewed gum. We analyzed the short-term clinical outcomes between the two groups to evaluate the effect of gum chewing.

Results

The first passage of gas was slightly earlier in group B, but the difference was not significant. However, the length of hospital stay was 6.7 days in group B, which was significantly shorter than that in group A (7.3 days, P = 0.018).

Conclusion

This study showed that length of postoperative hospital stay was shorter in the gum-chewing group. In future studies, we expect to elucidate the effect of gum chewing on the postoperative recovery more clearly.

Chewing gums has stimulatory effects on bowel function in patients undergoing cesarean section: a randomized controlled trial

The aim of study was to investigate the effect of postoperative gum chewing on the recovery of bowel function after cesarean section. Total 100 women delivered by lower uterine segment section cesarean under local anesthesia (spinal). Eligible patients were randomly allocated into two groups: a gum-chewing group (n=50) or a control group (n= 50). The gum-chewing group participants who received one stick of sugarless gum for one hours, three times daily immediately after recovery from anesthesia and the control group had the usual postoperative care until being discharged. All women were followed up regularly until discharge from hospital, and recorded the times to the first bowel sounds of normal intestinal sounds, the time to the first passage of flatus, the time to the first feeling of hunger, and the time to the first defecation. The operative data, postoperative tolerance of gum chewing, and postoperative complications were documented. There was no statistically significant difference between the two groups in terms of demographic characteristics such as age, body mass index, parity, duration of surgery, number of miscarriages and curettages, time to the first feeding, the amount of serum intake, and type of cesarean section. The mean average postoperative interval of the first bowel sounds (21.9 versus 26.1 hours, p= 0.016), the first feeling of hunger (11.8 versus 14.5 hours, p= 0.050), the first passage of flatus (24.8 versus 30.0 hours, P=0.002), the first defecation (30.6 versus 38.4 hours, P= 0.0001) was significantly shorter compared to the control group.

Influence of gum chewing on postoperative bowel activity after complete staging surgery for gynecological malignancies: a randomized controlled trial

OBJECTIVE

To investigate whether gum chewing affects the return of bowel function after complete staging surgery for gynecologic malignancies.

METHODS

A total of 149 patients undergoing abdominal complete surgical staging for various gynecological cancers were randomized into a gum-chewing group (n=74) or a control group (n=75). The patients chewed sugarless gum three times from the first postoperative morning until the first passage of flatus. Each chewing session lasted 30 min. Total abdominal hysterectomy with systematic pelvic and para-aortic lymphadenectomy was performed on all patients as part of complete staging surgery. Groups were compared in terms of time to first bowel movement time, first flatus and feces pass time, postoperative analgesic and antiemetic drug requirement, postoperative oral intake tolerance, mild ileus symptoms and hospital stay.

RESULTS

The mean time to flatus (34.0 ± 11.5 vs. 43.6 ± 14.0 h; p<0.001), mean time to defecation (49.6 ± 18.7 vs. 62.5 ± 21.5h; p<0.001), mean time to bowel movement (41.5 ± 15.7 vs. 50.1 ± 5.9h; p=0.001), mean time to tolerate diet (4.0 ± 0.8 vs. 5.0 ± 0.9 days; p<0.001), mean length of hospital stay (5.9 ± 1 vs. 7.0 ± 1.4 days; p<0.001) were significantly reduced in patients that chewed gum compared with controls. Mild ileus symptoms were observed in 27 (36%) patients in the control group compared to 11(14.9%) patients in the gum-chewing group [relative risk, 2.4; 95% confidence interval, 1.2-4.5; p=0.004]. Severe symptoms were observed in two patients (2.7%) in the control group.

CONCLUSIONS

Gum chewing early in the postoperative period following elective total abdominal hysterectomy and systematic retroperitoneal lymphadenectomy hastens time to bowel motility and ability to tolerate feedings. This inexpensive and well-tolerated treatment should be added as an adjunct in postoperative care of gynecologic oncology.

Chewing gum reduces postoperative ileus following abdominal surgery: a meta-analysis of 17 randomized controlled trials

BACKGROUND AND AIM

Chewing gum proposal has been used in surgery to reduce postoperative ileus for more than 10 years; however, the efficacy remains imprecise. The aim of this study was to accurately assess whether the use of the chewing gum could reduce duration of postoperative ileus following the abdominal surgery.

METHODS

A systematic review was conducted in Medline, EMBASE, and the Cochrane Library through December 2012 to identify randomized controlled trials comparing with and without the use of chewing gum in patients undergoing abdominal surgery. The outcome of interest was time to flatus, time to bowel movement, and length of stay. Subgroup analyses were performed to examine the impact of different studies structural design. Cumulative meta-analyses were used to examine how the evidence has changed over time.

RESULTS

Seventeen randomized controlled trials involving 1374 participants were included. Overall time (in days) for the patients to pass flatus (weighted mean difference [WMD], -0.31; 95% confidence interval [CI], -0.43 to -0.19; P = 0.000); time to bowel movement (WMD, -0.51; 95% CI, -0.73 to -0.29; P = 0.000); and length of stay (WMD, -0.72; 95% CI, -1.02 to -0.43; P = 0.000) were significantly reduced in the treatment group. However, both of these results demonstrated significant heterogeneity. No evidence of publication bias was observed. Cumulative meta-analysis showed that chewing gum reduces duration of postoperative ileus that has been available for over 6 years.

CONCLUSIONS

Results of the meta-analysis suggest that chewing gum following abdominal surgery offers benefits in reducing the time of postoperative ileus.

Chewing sugar-free gum reduces ileus after cesarean section in nulliparous women: a randomized clinical trial

Background

Gum chewing after cesarean section may stimulate bowel motility and decrease duration of postoperative ileus.

Objectives

The current study assessed the effect of chewing sugar-free gum on the return of bowel function, where cesarean section had been performed in nulliparous women.

Materials and Methods

In a randomized clinical trial, 60 patients, scheduled for cesarean section were randomly divided in to 2 groups gum-chewing group (n = 30) and control group (n = 30) postoperatively. The patients in the gum-chewing group postoperatively chewed sugar free gum 3 times daily each time for 1 hour until discharge. The patients' demographic characteristics, duration of surgery, mean hunger time, flatus and bowel motility were compared in the two groups.

Results

There was no significant difference between the 2 groups regarding patient demographics, intraoperative, and postoperative care. In the gum-chewing and the control group there was a significant difference in the mean postoperative interval of the first bowel movement (20.89 ± 8.8 versus 27.93 ± 9.3 hours, P = 0.004), the first feeling of hunger (10.37 ± 6.0 versus 16.33 ± 9.3 hours, P = 0.005), the first passage of flatus (25.02 ± 5.8 versus 31.08 ± 9.7 hours, P = 0.003), and the first defecation (31.17 ± 5.3versus 40.08 ± 8.8 hours, P = 0.000) respectively, which were significantly shorter in the gum-chewing group compared to those of the control group. There were no major complications in either group. All patients in the gum-chewing group tolerated it without any major complications and side effects.

Conclusions

The study results demonstrated that bowel motility after cesarean section in nulliparous women can be accelerated by gum chewing which is a useful, inexpensive and well-tolerated method for mothers in post-cesarean section.

A prospective randomized controlled trial of sugared chewing gum on gastrointestinal recovery after major colorectal surgery in patients managed with early enteral feeding

BACKGROUND

A number of small prospective studies with conflicting results have evaluated the effect of sugar-free chewing gum on postoperative GI recovery in patients initially maintained nil per os after major colorectal surgery.

OBJECTIVE

We sought to evaluate the effect of sugared chewing gum in combination with early enteral feeding on recovery of GI function after major colorectal surgery to ascertain any additive effects of this combination.

DESIGN

This was a randomized prospective study.

SETTING

This study was conducted at a single-institution tertiary referral center.

PATIENTS

Patients undergoing major colorectal surgery were included.

INTERVENTIONS

Patients were randomly assigned to sugared chewing gum (Gum) (instructed to chew 3 times daily; 45 minutes each time for 7 days postoperatively) or No Gum after major colorectal surgery.

MAIN OUTCOME MEASURES

The primary outcome measured was time to tolerating low residue diet without emesis for 24 hours. The secondary outcomes measured were time to flatus, time to bowel movement, postoperative hospital stay, postoperative pain, nausea, and appetite.

RESULTS

One hundred fourteen patients (60 No Gum; 54 Gum) were included in our analysis after randomization. There was no significant difference in time to tolerating a low-residue diet, time to flatus, time to bowel movement, length of postoperative hospital stay, postoperative complications, postoperative pain, nausea, or appetite between patients assigned to Gum or No Gum. There was an increased incidence of bloating, indigestion, and eructation in the Gum group (13%) in comparison with the No Gum group (2%) (p = 0.03).

LIMITATIONS

Study subjects and investigators were not blinded. Multiple types of operations may cause intergroup variability.

CONCLUSIONS

There does not appear to be any benefit to sugared chewing gum in comparison with no gum in patients undergoing major colorectal surgery managed with early feeding in the postoperative period. There may be increased incidence of bloating, indigestion, and eructation, possibly related to swallowed air during gum chewing.

Effects of gum chewing on recovery of bowel function following cesarean section: a randomized controlled trial

PURPOSE

To evaluate the effects of gum chewing on recovery of bowel function after cesarean section.

METHODS

Fifty pregnant women who underwent cesarean section at Chiang Mai University hospital from September 2010 to December 2010 were recruited. After cesarean section, patients were randomized into two groups. In group 1 (conventional), patients were fed according to conventional feeding protocol without gum chewing. For group 2 (gum chewing), patients were asked to chew two pieces of sugarless gum for 30 min in the morning, noon, evening and bedtime until the first flatus, along with conventional postoperative feeding protocol. Categorical variables were analyzed using the Chi-square or Fischer's exact test, as appropriate. For continuous variables with skewed distribution, the Mann-Whitney U test was employed.

RESULTS

There were 25 patients in each group. Median time to the first flatus was shorter in the gum chewing group (36.37 vs. 41.33 h, P = 0.02). Also, there was a trend toward less abdominal cramping on days 1 and 2 in the gum chewing group. However, no difference in other outcome measures of bowel function recovery and ileus-related complications between the groups could be demonstrated. Approximately three-fourth of the women in each group had good tolerance to their first meal. Hospital stay and participants' satisfaction to the assigned feeding schedules were comparable between the study groups.

CONCLUSION

Gum chewing is associated with faster recovery of bowel function following cesarean section. It is safe, practical, inexpensive, and well tolerated.

Impaired gastric response to modified sham feeding in patients with postprandial distress syndrome

BACKGROUND

Impaired vagal function has been reported to be important in some patients with functional dyspepsia (FD). However, the pathophysiologic mechanisms influencing the cephalic phase of vagal activity in FD are incompletely understood. The aim of this study was to investigate the gastric response to modified sham feeding (MSF) on ultrasound and cardiovascular autonomic function in FD patients.

METHODS

Nineteen patients with postprandial distress syndrome (PDS, 11 men and eight women; mean age: 48.2 years) and 26 healthy subjects (HS, 13 men and 13 women; mean age: 45.0 years) were studied prospectively. Firstly, cardiovascular autonomic function was assessed by spectral analysis of RR interval variability. Antral contraction was then evaluated by ultrasonography after MSF was performed to stimulate the cephalic phase of vagal activity.

KEY RESULTS

Spectral analysis of RR interval variability showed that the high-frequency component was significantly smaller in the patients than in the HS (P<0.01). The frequency of antral contraction in response to MSF over 15 min was also significantly lower in the PDS patients than in the HS. The 15-min integrated antral contractile response (area under the contraction vs time curve) was significantly smaller in the PDS patients than in the HS (P<0.01). Univariate analysis revealed a modest correlation between the high-frequency component of RR interval variability and the area under the contraction vs time curve (n=46, r=0.49, P<0.01).

CONCLUSIONS & INFERENCES

Autonomic abnormalities affecting the cephalic phase of vagal activity may be important in the pathogenesis of FD.

Impact of bolus volume on small intestinal intra-luminal impedance in healthy subjects

AIM: To assess the impact of bolus volume on the characteristics of small intestinal (SI) impedance signals.

METHODS: Concurrent SI manometry-impedance measurements were performed on 12 healthy volunteers to assess the pattern of proximal jejunal fluid bolus movement over a 14 cm-segment. Each subject was given 34 boluses of normal saline (volume from 1 to 30 mL) via the feeding tube placed immediately above the proximal margin of the studied segment. A bolus-induced impedance event occurred if there was > 12% impedance drop from baseline, over ≥ 3 consecutive segments within 10 s of bolus injection. A minor or major impedance event was defined as a duration of impedance drop < 60 s or ≥ 60 s, respectively.

RESULTS: The minimum volume required for a detectable SI impedance event was 2 mL. A direct linear relationship between the SI bolus volume and the occurrence of impedance events was noted until SI bolus volume reached 10 mL, a volume which always produced an impedance flow event. There was a moderate correlation between the bolus volume and the duration of impedance drop (r = 0.63, P < 0.0001) and the number of propagated channels (r = 0.50, P < 0.0001). High volume boluses were associated with more major impedance events (≥ 10 mL boluses = 63%, 3 mL boluses = 17%, and < 3 mL boluses = 0%, P = 0.02).

CONCLUSION: Bolus volume had an impact on the type and length of propagation of SI impedance events and a threshold of 2 mL is required to produce an event.

beta-Glucan-enriched bread reduces energy intake and modifies plasma ghrelin and peptide YY concentrations in the short term

Dietary fibre consumption may help to control appetite and to reduce calorie intake. Underlying molecular mechanisms were not fully investigated. The aim of this study was to evaluate the effect of barley beta-glucans on short-term appetite and on satiety-related hormones in healthy subjects. Fourteen volunteers were selected and randomly assigned to have isocaloric breakfasts including a 3% beta-glucan-enriched bread (betaGB) or a control bread (CB). Post-breakfast individual self-records of appetite ratings and measure of calorie intake at an ad libitum lunch as well as measure of blood glucose, insulin, ghrelin and PYY concentrations, were performed. betaGB determined a significant higher reduction of hunger and increase of fullness and satiety than CB. Accordingly, a 19% reduction of energy intake at lunch subsequent to betaGB consumption compared to CB, was recorded. A 23% lower AUC(60-180) of plasma ghrelin and a 16% higher total AUC of PYY response after betaGB than CB consumption, independent from insulin response, was found. Glucose response was also blunted by betaGB vs CB. Barley beta-glucans were able to control appetite in the short term by modulating sensations and reducing energy intake. Data suggested for the first time that satiety effect of beta-glucans are mediated by ghrelin and PYY.

Sham feed or sham? A meta-analysis of randomized clinical trials assessing the effect of gum chewing on gut function after elective colorectal surgery

PURPOSE

Enhanced recovery programs aim to expedite gut function after elective colorectal surgery. Early oral feeding simulates gut function but is not always feasible. Gum chewing, a form of sham feed, is an alternative. We assessed current evidence for gum chewing and gut function.

STUDY DESIGN

All randomized controlled trials (RCTs) between 1990 and 2008 comparing gum chewing with controls/placebo were analyzed irrespective of language, blinding, or publication bias. The Jadad scale was used to assess study quality. Endpoints were time to flatus/feces, postoperative complications, and hospital stay. Random and fixed models were employed to aggregate study endpoints and assess heterogeneity.

RESULTS

Six RCTs containing 256 patients were included. Significant heterogeneity was identified and random effects model was employed. Heterogeneity may be explained through variations in delivery of surgical care. Significant reductions in the time to flatus and time to feces were identified but no significant difference in hospital or in-hospital postoperative complications were found.

CONCLUSIONS

Gum chewing significantly reduced time to flatus and feces; however, hospital stay and postoperative complications were not reduced. Significant study heterogeneity means that these results should be interpreted with caution.

Is gum chewing useful for ileus after elective colorectal surgery? A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

The evaluation of the usefulness of gum chewing for postoperative ileus has given inconclusive results. We evaluated the efficacy of gum chewing in the treatment of ileus after elective colorectal surgery.

MATERIALS AND METHODS

We performed a meta-analysis of randomized clinical trials comparing the effect of gum chewing+standard treatment vs. standard treatment on ileus after colorectal surgery. MEDLINE, EMBASE, the Cochrane Controlled Trial Register, and the Cochrane Database of Systematic Reviews were searched until August 2008. Primary outcomes were time to first flatus, time to first passage of feces, and length of hospital stay. The mean difference (MD) in hours was calculated with the random effects model to assess the effect of gum chewing on the outcomes.

RESULTS

Six trials including 244 patients were analyzed. Time to first flatus was significantly reduced with gum chewing+standard treatment compared to standard treatment alone (MD -14 h, 95% confidence interval [95%CI] -23.5 to -4.6). Time to first passage of feces was significantly reduced (MD -25 h, 95%CI -42.3 to -7.7), but the length of hospital stay was only marginally reduced (MD -26.2 h, 95%CI -57.5 to 5.2) with gum chewing.

CONCLUSION

In patients with ileus after colonic surgery, gum chewing in addition to standard treatment significantly reduces the time to first flatus and the time to first passage of feces when compared to standard treatment alone. There is also a trend to reduce the length of hospital stay. Gum chewing should be added to the standard treatment of these patients.

Methods for measurement of gastric motility

There is an array of tests available to measure gastric motility. Some tests measure end points, such as gastric emptying, that result from several different functions, whereas other tests are more specific and test only a single parameter, such as contractility. This article reviews the tests most commonly available in practice and research to evaluate in vivo the gastric functions of emptying, accommodation, contractility, and myoelectrical activity. The rationale for testing, the relative strengths and weaknesses of each test, and technical details are summarized. We also briefly indicate the applications and validations of the tests for use in experimental animal studies.

Clinical trial: effectiveness of chewing-gum in accelerating capsule endoscopy transit time--a prospective randomized, controlled pilot study

BACKGROUND

Capsule endoscopy (CE) fails to reach the caecum in approximately 20% of patients. Data suggest that chewing-gum, simulating sham feeding, provokes the cephalic phase of gastrointestinal (GI) motor response and may increase GI motility.

AIM

To determine whether chewing-gum increases the ability of CE reaching the caecum.

METHODS

Prospective, randomized, single-blinded controlled trial. Ninety-three consecutive patients were randomized either to use chewing-gum (n = 47) or not (n = 46). All patients received the identical bowel preparation. Patients chewed one piece of gum for approximately 30 min every 2 h. Two blinded gastroenterologists examined all studies. The number of CE that reached the caecum within 8-h, gastric transit time (GTT) and small bowel transit time (SBTT) were evaluated in all patients.

RESULTS

The CE percentage passed into the caecum was higher in the chewing-gum group compared with those in the other (83.0% vs. 71.7% respectively, P = 0.19). Both GTT and SBTT were significantly shorter in the chewing-gum vs. control group [40.8 min (interquartile range: 21-61 min) vs. 56.1 min (interquartile range: 22-78 min) (P = 0.045) and 229.1 min (interquartile range: 158-282 min) vs. 266.2 min (interquartile range: 204-307 min) (P = 0.032) respectively]. Chewing-gum did not adversely affect CE image quality.

CONCLUSIONS

Chewing-gum significantly reduces GTT and SBTT during CE. Its use may improve the likelihood of the capsule reaching the caecum without affecting CE image quality.

Use of chewing gum in reducing postoperative ileus after elective colorectal resection: a systematic review

PURPOSE

Published studies comparing the addition of chewing gum to standardized postoperative care to shorten postoperative ileus showed controversial results. This study was designed to conduct a systematic review of all relevant trials on chewing gum to reduce postoperative ileus after colorectal resection.

METHODS

All published trials that compared the additional use of gum chewing with standard postoperative management were identified from Ovid MEDLINE, EMBASE, CINAHL, and All Evidence-Based Medicine Reviews between January 1991 and January 2007. The clinical outcomes were extracted and meta-analysis was performed by Forest plot review.

RESULTS

Five randomized, controlled trials with 158 (94 males) patients with mean age of 61.9 years were included. Seventy-eight patients received an addition of gum chewing and 80 had standard postoperative care for colorectal resection. Operating time (P = 0.78) and blood loss (P = 0.48) were similar. All patients tolerated the gum without any side-effects. With combined standard postoperative care and gum chewing, the patients passed flatus 24.3 percent earlier (weighted mean difference, -20.8 hours; P = 0.0006) and had bowel movement 32.7 percent earlier (weighted mean difference, -33.3 hours; P = 0.0002). They were discharged 17.6 percent earlier than those having ordinary postoperative treatment (weighted mean difference, -2.4 days; P < 0.00001). The gum-chewing group was associated with similar overall postoperative complication rate (odds ratio, 0.45; P = 0.05) with individual complication showing a trend favoring gum chewing, although they were not of statistical significance. Readmission (odds ratio, 0.36; P = 0.24) and reoperation rates (odds ratio, 1.36; P = 0.83) of the two groups were similar.

CONCLUSIONS

The use of gum chewing in the postoperative period is a safe method to stimulate bowel motility and reduce ileus after colorectal surgery.

The nocturnal jejunal migrating motor complex: defining normal ranges by study of 51 healthy adult volunteers and meta-analysis

Interdigestive human small bowel motility is characterized by the migrating motor complex (MMC). The aims of this study were to: (i) establish the normal range of variables of the nocturnal jejunal MMC and (ii) incorporate these data in a subsequent meta-analysis. Eighty-one recordings were performed by prolonged (24 h) ambulatory manometry in 51 subjects in two centres. Quantitative analysis was undertaken of 419 Phase III and 332 Phase II episodes. Adjusted mean values of seven variables were calculated using a mixed-effects model. Meta-analysis of pooled published data to generate a reliable 95% reference range was also performed. Adjusted mean values and confidence intervals are presented for all seven variables. Intrasubject variances were large in comparison with intersubject. Meta-analysis of 19 studies (356 pooled patients) meeting inclusion criteria produced wide reference ranges. At least five such ranges are useful for the detection of abnormality in the individual. This is the largest study of normal volunteers presented to date, with ranges for many variables produced using appropriate statistical methodology. A model for definition of abnormality has been proposed. We recommend that these data may be used by investigators in this field as a complement to other existing indicators of small bowel dysmotility.

Nutrient modulation of intestinal gas dynamics in healthy humans: dependence on caloric content and meal consistency

The actions of nutrients on gut transit of liquids and solids have been extensively studied, but the effects of meal ingestion on intestinal gas flow are unexplored. We hypothesized that meals of varying caloric content and consistency modulate gas transit to different degrees. Nine healthy volunteers underwent jejunal perfusion of physiological gas mixtures at 12 ml.min(-1).3 h, with ingestion of nothing (control), water (240 ml), 240-kcal liquid meals, and 240-kcal solid meals at the end of the second hour in separate studies. Gas was quantified from an intrarectal catheter. After an initial lag phase, gas evacuation approached steady state by the end of the fasting period. Solid and liquid caloric meals increased total gas volumes evacuated from 5-40 min after ingestion vs. control studies (P < 0.05). These increases resulted from increased numbers of bolus gas evacuations (P < 0.05), whereas bolus volumes, pressures, and flow rates were similar for all test conditions. Solid and liquid caloric meals elicited similar effects on bolus gas dynamic parameters, whereas water did not affect these measures vs. control (NS, not significant). Both caloric meals and the noncaloric liquid meal increased continuous gas flow, which represented <2% of total gas expulsion. In conclusion, caloric meals promote bolus gas transit in healthy humans, whereas noncaloric liquids have no effect. Solids stimulate early postprandial gas dynamics to the same extent as liquid meals of similar caloric content. Thus modulatory effects of meals on intestinal gas transit depend on their caloric content but not their consistency.

Does gum chewing reduce postoperative ileus following open colectomy for left-sided colon and rectal cancer? A prospective randomized controlled trial

OBJECTIVE

Postoperative ileus is common after colorectal resection and can prolong hospital stay. Gum chewing, a type of sham feeding, may to stimulate gut motility via cephalic-vagal stimulation, and thereby reduce the length of ileus. This study aimed to determine whether gum chewing in the immediate postoperative period facilitated recovery from ileus following resection for left-sided colorectal cancer.

METHODS

In a prospective randomized control trial, 38 patients undergoing open surgery for left-sided colorectal cancer were allocated to standard postoperative care (control group, n = 19) or to standard postoperative care plus the immediate use of chewing gum (treatment group, n = 19).

RESULT

Control patients passed flatus by mean of 2.7 days (SD 1.0) and faeces by 3.9 days (SD 1.5); for the treatment group, this was 2.4 days (SD 1.0) and 3.2 days (SD 1.5) respectively, (NS, P = 0.56 and P = 0.38). Length of hospital stay was 11.1 days (SD 7.3) in control group and 9.4 days (SD 2.5) in the treatment group (NS, P = 0.75).

CONCLUSION

The addition of gum chewing to a standardized postoperative regimen did not reduce the period of postoperative ileus or shorten length of stay following open surgery for left-sided colorectal cancer.