Transcutaneous Neuromodulation at Posterior Tibial Nerve and ST36 for Chronic Constipation. Evid Based Complement Alternat Med. 2014;2014:560802. [PMID: 25431612 DOI: 10.1155/2014/560802]

The impact of transcutaneous electrical acustimulation (TEA) on rectal distension-induced pain in patients with irritable bowel syndrome (IBS)-A study to determine the optimal TEA delivery modalities and effects on rectal sensation and autonomic function

BACKGROUND

Treatment options for abdominal pain in IBS are inadequate. TEA was reported effective treatment of disorders of gut-brain interaction but its mechanism of action and optimal delivery method for treating pain in IBS are unknown. This study aims to determine the most effective TEA parameter and location to treat abdominal pain in patients with IBS-Constipation and delineate the effect of TEA on rectal sensation and autonomic function.

METHODS

Nineteen IBS-C patients underwent TEA at acupoints ST36 (leg), PC6 (wrist), or sham-acupoint. Each patient was studied in five randomized sessions on separate days: (1) TEA/ST36-100 Hz; (2) TEA/ST36-25 Hz; (3) TEA/PC6-100 Hz; (4) TEA/PC6-25 Hz; (5) TEA/Sham-25 Hz. In each session, barostat-guided rectal distention (RD) was performed before and after TEA. Patients graded the RD-induced pain and recorded three rectal sensation thresholds. A heart rate variability (HRV) signal was derived from the electrocardiogram for autonomic function assessment.

KEY RESULTS

Studied patients were predominantly female, young, and Caucasian. Compared with baseline, patients treated with TEA/ST36-100 Hz had significantly decreased pain scores at RD pressure-points 20-50 mmHg (p < 0.04). The average pain reduction was 40%. Post-treatment scores did not change significantly with other TEA modalities except with sham-TEA (lesser degree compared to ST36-100 Hz, p = 0.04). TEA/ST36-100, but not other modalities, increased the rectal sensation threshold (first sensation: p = 0.007; urge to defecate: p < 0.026). TEA/ST36-100 Hz was the only treatment that significantly decreased sympathetic activity and increased parasympathetic activity with and without RD (p < 0.04).

CONCLUSIONS & INFERENCES

TEA at ST36-100 Hz is superior stimulation point/parameter, compared to TEA at PC-6/sham-TEA, to reduce rectal distension-induced pain in IBS-C patients. This therapeutic effect appears to be mediated through rectal hypersensitivity reduction and autonomic function modulation.

Ameliorating effects of transcutaneous auricular vagus nerve stimulation on a mouse model of constipation-predominant irritable bowel syndrome

Limited treatment options have been shown to alter the natural course of constipation-predominant irritable bowel syndrome (IBS-C). Therefore, safer and more effective approaches are urgently needed. We investigated the effects of transcutaneous auricular vagus nerve stimulation (taVNS) in a mouse model of IBS-C. In the current study, C57BL/6 mice were randomly divided into normal control, IBS-C model control, sham-electrostimulation (sham-ES), taVNS, and drug treatment groups. The effects of taVNS on fecal pellet number, fecal water content, and gastrointestinal transit were evaluated in IBS-C model mice. We assessed the effect of taVNS on visceral hypersensitivity using the colorectal distention test. 16S rRNA sequencing was used to analyze the fecal microbiota of the experimental groups. First, we found that taVNS increased fecal pellet number, fecal water content, and gastrointestinal transit in IBS-C model mice compared with the sham-ES group. Second, taVNS significantly decreased the abdominal withdrawal reflex (AWR) score compared with the sham-ES group, thus relieving visceral hyperalgesia. Third, the gut microbiota outcomes showed that taVNS restored Lactobacillus abundance while increasing Bifidobacterium probiotic abundance at the genus level. Notably, taVNS increased the number of c-kit-positive interstitial cells of Cajal (ICC) in the myenteric plexus region in IBS-C mice compared with the sham-ES group. Therefore, our study indicated that taVNS effectively ameliorated IBS-C in the gut microbiota and ICC.

Transcutaneous Electrical Acustimulation Improves Constipation Symptoms and Accelerates Colonic Transit in Patients With Slow Transit Constipation Through Autonomic Mechanism

OBJECTIVES

Nearly half of patients with slow transit constipation (STC) are not completely satisfied with their traditional remedies. We aimed to evaluate the therapeutic value and possible involved mechanism of transcutaneous electrical acustimulation (TEA) at ST36 in patients with STC.

MATERIALS AND METHODS

Seventy patients with STC were randomly divided into TEA (n = 35) and sham-TEA (n = 35) to undergo a two-week treatment with TEA at ST36 or sham point. After the two-week treatment, 18 patients from each group randomly underwent a few physiological tests, including the electrocardiogram (ECG), anorectal manometry, colon transit test, and blood drawing. After a two-week washout period, TEA was performed in both groups for two weeks.

RESULTS

Spontaneous bowel movements per week were increased, and scores of constipation symptoms were decreased, after a two-week blind TEA but not sham-TEA, which were sustained after a two-week washout period. Improvement in quality of life and psychologic states also was observed with blind TEA treatment. Mechanistically, the two-week blind TEA accelerated colon transit assessed by barium strip excretion rate (the effect was sustained after a two-week washout period), enhanced vagal nerve activity evaluated by the spectral analysis of heart rate variability derived from the ECG, and decreased circulating vasoactive intestinal peptide.

CONCLUSIONS

Noninvasive TEA relieves constipation and improves quality of life and psychologic states in patients with STC, and the effects are sustained for ≥two weeks. The therapeutic effects of TEA may be attributed to the acceleration of colon transit and decrease of vasoactive intestinal peptide mediated through the vagal mechanism.

Transcutaneous Posterior Tibial Nerve Stimulation: An Adjuvant Treatment for Intractable Constipation in Children

BACKGROUND

Functional constipation can lead to painful defecations, fecal incontinence, and abdominal pain, significantly affecting a child's quality of life. Treatment options include non-pharmacological and pharmacological approaches, but some cases are intractable and require alternative interventions like neuromodulation. A subtype of neuromodulation, called Transcutaneous Posterior Tibial Nerve Stimulation (TPTNS), comprises electrical stimulation at the ankle level, by means of electrodes fixed to the skin. TPTNS is a minimally invasive, easy-to-apply technique that can potentially improve constipation symptoms in the pediatric population by stimulating the sacral nerves.

AIM

To evaluate the clinical results and applicability of TPTNS as an adjuvant treatment for children and adolescents with functional constipation.

METHODS

Between April 2019 and October 2021, 36 patients diagnosed with functional constipation according to the Rome IV Criteria were invited to participate in the study. The study followed a single-center, uncontrolled, prospective cohort design. Patients received TPTNS for 4 or 8 weeks, with assessments conducted immediately after the periods of TPTNS and 4 weeks after the end of the intervention period. The data normality distribution was determined by the Shapiro-Wilk test. The Wilcoxon test and Student's t-test for paired samples were used to compare quantitative variables, and the McNemar test was used to compare categorical variables.

RESULTS

Of the 36 enrolled patients, 28 children and adolescents with intractable function constipation completed the study, receiving TPTNS for 4 weeks. Sixteen patients (57.1%) extended the intervention period for 4 extra weeks, receiving 8 weeks of intervention. TPTNS led to significant improvements in stool consistency, frequency of defecation, and bowel function scores, with a reduction in abdominal pain. Quality of life across physical and psychosocial domains showed substantial enhancements. The quality of life-related to bowel habits also improved significantly, particularly in lifestyle, behavior, and embarrassment domains. The positive effects of this intervention are seen relatively early, detected after 4 weeks of intervention, and even 4 weeks after the end of the intervention. TPTNS was well-tolerated, with an adherence rate of approximately 78%, and no adverse effects were reported.

CONCLUSIONS

TPTNS is an adjuvant treatment for intractable functional constipation, improving bowel function and quality of life. The effects of TPTNS were observed relatively early and sustained even after treatment cessation.

Effect and mechanism of needleless transcutaneous neuromodulation on gastrointestinal function after pancreaticoduodenectomy

BACKGROUND

Gastrointestinal motility disorders tend to develop after pancreaticoduodenectomy (PD). The objectives of this study were: (1) to investigate the impact of needleless transcutaneous neuromodulation (TN) on the postoperative recuperation following pancreaticoduodenectomy (PD), and (2) to explore the underlying mechanisms by which TN facilitates the recovery of gastrointestinal function after PD.

METHODS

A total of 41 patients scheduled for PD were randomized into two groups: the TN group (n = 21) and the Sham-TN group (n = 20). TN was performed at acupoints ST-36 and PC-6 twice daily for 1 h from the postoperative day 1 (POD1) to day 7. Sham-TN was performed at non-acupoints. Subsequent assessments incorporated both heart rate variation and dynamic electrogastrography to quantify alterations in vagal activity (HF) and gastric pacing activity.

RESULTS

1)TN significantly decreased the duration of the first passage of flatus (p < 0.001) and defecation (p < 0.01) as well as the time required to resume diet (p < 0.001) when compared to sham-TN;2)Compared with sham-TN, TN increased the proportion of regular gastric pacing activity (p < 0.01);3) From POD1 to POD7, there was a discernible augmentation in HF induced by TN stimulation(p < 0.01);4) TN significantly decreased serum IL-6 levels from POD1 to POD7 (p < 0.001);5) TN was an independent predictor of shortened hospital stay(β = - 0.349, p = 0.035).

CONCLUSION

Needleless TN accelerates the recovery of gastrointestinal function and reduces the risk of delayed gastric emptying in patients after PD by enhancing vagal activity and controlling the inflammatory response.

Noninvasive electrical neuromodulation for gastrointestinal motility disorders

INTRODUCTION

Gastrointestinal motility disorders are highly prevalent without satisfactory treatment. noninvasive electrical neuromodulation is an emerging therapy for treating various gastrointestinal motility disorders.

AREAS COVERED

In this review, several emerging noninvasive neuromodulation methods are introduced, including transcutaneous auricular vagal nerve stimulation, percutaneous auricular vagal nerve stimulation, transcutaneous cervical vagal nerve stimulation, transcutaneous electrical acustimulation, transabdominal interference stimulation, tibial nerve stimulation, and translumbosacral neuromodulation therapy. Their clinical applications in the most common gastrointestinal motility are discussed, including gastroesophageal reflux disease, functional dyspepsia, gastroparesis, functional constipation, irritable bowel syndrome, and fecal incontinence. PubMed database was searched from 1995 to June 2023 for relevant articles in English.

EXPERT OPINION

Noninvasive neuromodulation is effective and safe in improving both gastrointestinal symptoms and dysmotility; it can be used when pharmacotherapy is ineffective. Future directions include refining the methodology, improving device development and understanding mechanisms of action.

Non-invasive neuromodulation: an emerging intervention for visceral pain in gastrointestinal disorders

Gastrointestinal (GI) disorders, which extend from the esophagus to the anus, are the most common diseases of the GI tract. Among these disorders, pain, encompassing both abdominal and visceral pain, is a predominant feature, affecting the patients' quality of life and imposing a substantial financial burden on society. Pain signals originating from the gut intricately shape brain dynamics. In response, the brain sends appropriate descending signals to respond to pain through neuronal inhibition. However, due to the heterogeneous nature of the disease and its limited pathophysiological understanding, treatment options are minimal and often controversial. Consequently, many patients with GI disorders use complementary and alternative therapies such as neuromodulation to treat visceral pain. Neuromodulation intervenes in the central, peripheral, or autonomic nervous system by alternating or modulating nerve activity using electrical, electromagnetic, chemical, or optogenetic methodologies. Here, we review a few emerging noninvasive neuromodulation approaches with promising potential for alleviating pain associated with functional dyspepsia, gastroparesis, irritable bowel syndrome, inflammatory bowel disease, and non-cardiac chest pain. Moreover, we address critical aspects, including the efficacy, safety, and feasibility of these noninvasive neuromodulation methods, elucidate their mechanisms of action, and outline future research directions. In conclusion, the emerging field of noninvasive neuromodulation appears as a viable alternative therapeutic avenue for effectively managing visceral pain in GI disorders.

Transcutaneous electrical stimulation for gastrointestinal motility disorders

BACKGROUND/PURPOSE

Gastrointestinal (GI) dysmotility is categorized by muscle or nerve dysfunctions in any portion of the GI tract, which leads to abnormalities in GI motor and sensory function. Symptoms may vary depending on the organ affected and can be debilitating. Treatment usually involves diet and lifestyle changes. Pharmacotherapy is limited in effectiveness with various side effects. Transcutaneous electrical stimulation (TES), a noninvasive, needleless technique that provides electrical stimulation using cutaneous non-needle electrodes, has become increasingly popular. It has been shown to be beneficial in treating GI motility disorders.

METHODS

This review paper navigates through the different TES techniques, including transcutaneous peripheral nerve (vagal/sacral/tibial nerves) electrical stimulation, transcutaneous electrical acustimulation (stimulation via acupuncture point), transcutaneous interferential current therapy, and transcutaneous electrical nerve stimulation.

KEY RESULTS

As we delve deeper, we explore the promising effects of TES on dysphagia, gastroesophageal reflux disease, functional dyspepsia, gastroparesis, postoperative ileus, constipation, and irritable bowel syndrome. The literature at hand speaks volumes about the therapeutic prowess of this noninvasive technique.

CONCLUSION & INFERENCES

The time is ripe to evaluate further the full therapeutic potential of TES, a noninvasive, nonpharmaceutical, nonsurgical, and home-based self-administrative technique in managing GI motility disorders.

Clinical efficacy and mechanism of transcutaneous neuromodulation on ineffective esophageal motility in patients with gastroesophageal reflux disease

BACKGROUND

Esophageal motility disorder is one of the pathogenesis of gastroesophageal reflux disease (GERD). The clinical and functional relationship between the ineffective esophageal motility (IEM) and GERD have been found. PPI is a widely used drug of this diaease, but some patients have poor efficacy. The purpose of this study was to investigate the efficacy and possible mechanism of Transcutaneous Neuromodulation in these patients.

METHODS

Fifty-six patients with GERD with IEM were enrolled and randomly divided into two groups, one group was TN ST-36 group, the other group was sham TN group. The GERD questionnaire (GerdQ), quality of life score, MOS item short from health survey (SF-36), Hospital Anxiety and Depression Scale (HADS) were used to assess the severity of symptoms. High-resolution esophageal manometry (HRM) test was performed to assess low esophageal sphincter (LES) pressure and distal contractile integral (DCI). The heart rate variability (HRV) test was performed to assess autonomic nervous function.

KEY RESULTS

Compared with sham TN, chronic TN treatment decreased the GERD-Q score (p < 0.001). The anxiety score (p = 0.058) and depression score (p = 0.156) were decreased, but there were no statistical differences. Chronic TN treatment also significantly improved the quality of life of patients, mainly in physical function, physical pain, overall health, vitality, social function, emotional function, and mental health. Acute TN treatment increased the DCI (p < 0.001) and LES pressure (p < 0.001) significantly and decreased the combined percentage of failed and weak peristalsis (p < 0.001). Concurrently, acute TN enhanced vagal activity (p < 0.001).

CONCLUSIONS AND INFERENCES

IEM is an important link in the pathogenesis of GERD. Chronic TN treatment can significantly improve the clinical symptoms of patients. Acute TN treatment can significantly increase LES pressure and DCI and reduce the frequency of esophageal lost peristalsis and weak peristalsis. The improvement of esophageal motility in GERD patients with IEM by TN treatment may be related to the regulation of autonomic nervous function.

Roles of Heart Rate Variability in Assessing Autonomic Nervous System in Functional Gastrointestinal Disorders: A Systematic Review

Functional gastrointestinal disorders (FGID) and gastroesophageal reflux (GERD) disease affect a large global population and incur substantial health care costs. Impairment in gut-brain communication is one of the main causes of these disorders. The central nervous system (CNS) provides its inputs to the enteric nervous system (ENS) by modulating the autonomic nervous system (ANS) to control the gastrointestinal functions. Therefore, GERD and FGID's might be associated with autonomic dysfunction, which can be identified via heart rate variability (HRV). FGIDs may be treated by restoring the autonomic dysfunction via neuromodulation. This article reviews the roles of HRV in the assessment of autonomic function and dysfunction in (i) gastroesophageal reflux (GERD), and the following FGIDs: (ii) functional dyspepsia (FD) and gastroparesis, (iii) irritable bowel syndrome (IBS) and (iv) constipation. The roles of HRV in the assessment of autonomic responses to various interventions were also reviewed. We used PUBMED, Web of Science, Elsevier/Science direct and Scopus to search the eligible studies for each disorder, which also included the keyword 'heart rate variability'. The retrieved studies were screened and filtered to identify the most suitable studies using HRV parameters to associate the autonomic function with any of the above disorders. Studies involving both human and animal models were included. Based on analyses of HRV, GERD as well as the FGIDs were found to be associated with decreased parasympathetic activity and increased sympathetic nervous system activity with the autonomic balance shifted towards the sympathetic nervous system. In addition, the HRV methods were also reported to be able to assess the autonomic responses to various interventions (mostly neuromodulation), typically the enhancement of parasympathetic activity. In summary, GERD and FGIDs are associated with impaired autonomic dysfunction, mainly due to suppressed vagal and overactive sympathetic tone, which can be assessed noninvasively using HRV.

Biofeedback pelvic floor muscle training versus posterior tibial nerve electrostimulation in treatment of functional obstructed defecation: a prospective randomized clinical trial

Background

Functional obstructed defecation is a common anorectal problem among adult population. The objective was to compare the short-term efficacy of biofeedback pelvic floor muscle training versus transcutaneous posterior tibial nerve electrostimulation in treatment of patients with functional obstructed defecation.

Results

There were 41 patients completed the study. There were no statistical significant differences between biofeedback pelvic floor muscle training group and transcutaneous posterior tibial nerve electrostimulation group regarding different clinical characteristics, as well as, electrophysiological findings. There was statistically significant reduction in all outcome measures after intervention in both groups. The primary outcome measure was Modified obstructed defecation score. Secondary outcome measures were Patient Assessment of Constipation-Quality of Life questionnaire, time of toileting, and maximum anal pressure during straining to evacuate. No significant differences were present between both groups regarding different outcome measures in the pretreatment and post-treatment assessments. Successful outcome was reported in 81% of patients in biofeedback pelvic floor muscle training group in comparison to 40% of patients in the posterior tibial nerve electrostimulation group according to the Modified obstructed defecation score which was the primary outcome measure.

Conclusions

Both biofeedback pelvic floor muscle training and posterior tibial nerve electrostimulation are considered effective methods in the treatment of functional obstructed defecation. However, biofeedback pelvic floor muscle training seems to be more effective and superior in comparison to posterior tibial nerve electrostimulation. Posterior tibial nerve electrostimulation could be combined with biofeedback pelvic floor muscle training or considered as a second line therapy after failure of biofeedback pelvic floor muscle training.

Trial registration

Pan African Clinical Trials Registry, PACTR202009762113535. Registered 2 September 2020—retrospectively registered, https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=12321.

Sustained ameliorating effects and autonomic mechanisms of transcutaneous electrical acustimulation at ST36 in patients with chronic constipation

BACKGROUND AND AIMS

The treatment of chronic constipation is still a great challenge in clinical practice. This study aimed to determine the efficacy and sustained effects of transcutaneous electrical acustimulation (TEA) at acupoint ST36 on the treatment of chronic constipation and explore possible underlying mechanisms.

METHODS

Forty-four patients with chronic constipation were recruited and randomly assigned to a TEA group or sham-TEA group. A bowel diary was recorded by the patients. The Patient Assessment of Constipation Symptom (PAC-SYM) and the Patient Assessment of Constipation Quality of Life (PAC-QoL) questionnaires were administered during each visit. Anal and rectal functions were evaluated with anorectal manometry. Autonomic functions were assessed by the special analysis of heart rate variability derived from the ECG recording.

RESULTS

Compared with sham-TEA, 2-week TEA treatment significantly increased the number of spontaneous bowel movements (SBMs) (5.64 ± 0.54 vs. 2.82 ± 0.36, P < 0.001) and lowered the total scores of PAC-SYM (0.90 ± 0.14 vs. 1.35 ± 0.13, P < 0.001) and PAC-QoL (0.89 ± 0.13 vs. 1.32 ± 0.14, P < 0.05). TEA improved symptoms, as reflected by a reduction in the straining (P < 0.001), the incomplete defecation (P < 0.05), the frequency of emergency drug use (P < 0.05), the days of abdominal distension (P < 0.01) and an increase in intestinal satisfaction (P < 0.01). Interestingly, the effects of TEA on the improvement of weekly SBMs sustained four weeks after the cessation of treatment (P < 0.001). Anorectal manometry indicated that 2-week treatment of TEA lowered the threshold of first sensation (P < 0.05), desire of defecation (P < 0.01) and maximum tolerable volume (P < 0.001) compared with sham-TEA group. TEA also significantly enhanced vagal activity, reflected by high-frequency band of heart rate variability, compared with sham-TEA (57.86 ± 1.83 vs. 48.51 ± 2.04, P < 0.01).

CONCLUSION

TEA ameliorates constipation with sustained effects, which may be mediated via improvement of rectal sensitivity and enhancement of vagal activity.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov/], identifier [ChiCTR210004267].

Efficacy of Electroacupuncture Compared With Transcutaneous Electrical Stimulation for Severe Chronic Constipation: A Randomized Controlled Pilot Trial

BACKGROUND

To treat severe chronic constipation, both electroacupuncture (EA) therapy and transcutaneous electrical stimulation (TES) are safe and effective, but there is a lack of comparison between the 2 treatments. We sought to compare the therapeutic effect of EA relative to TES for the treatment of severe chronic constipation.

METHODS

We conducted a pilot randomized controlled trial. Seventy participants with severe chronic constipation were randomly allocated to the EA group or TES group. The acupoints in both groups are bilateral Tianshu (stomach 25), Fujie (spleen 14), and Shangjuxu (stomach 37). Each participant received 24 sessions of EA or TES during the treatment period of 8 weeks. Outcome measures were the proportion of participants with an increase from baseline of 1 or more complete spontaneous bowel movements (CSBMs) at week 8 and changes in the number of CSBMs and spontaneous bowel movements, stool character, difficulty in defecation, Patient Assessment of Constipation Quality of Life (PAC-QOL); the proportion of participants using rescue medicine and adverse reactions. Participants were followed for 24 weeks after the treatment.

RESULTS

Sixty of the 70 eligible participants completed the whole trial, 32 participants (91.43%) in the EA group and 28 participants (80.00%) in the TES group. There were 10 participants (14.29%) who dropped out during the whole study, 3 (8.57%) in the EA group, and 7 (20.00%) in the TES group. At weeks 20 and 32, 22 of 32 (68.75%) and 19 of 32 (59.38%) in the EA group met the clinical outcome of an increase of 1 or more CSBMs from the baseline, compared with 10 of 28 (35.71%) and 9 of 28 (32.14%) in the TES group ( P =0.019 and 0.042, respectively). At the same time, the proportions of participants having 3 or more CSBMs per week were 18 of 32 (56.25%) and 15 of 32 (46.88%) in the EA group, respectively, compared with 6 of 28 (21.43%) and 5 of 28 (17.86%) in the TES group ( P =0.008 and 0.027, respectively). Statistical differences between the 2 groups were maintained in the change from baseline in CSBMs during the follow-up period ( P =0.007 and 0.013, at week 20 and 32, respectively) and in the change from baseline in spontaneous bowel movements at week 20 ( P =0.007). Statistical significance was also observed in the decrease of PAC-QOL score after 8 weeks of treatment (mean±SD, EA: 19.06±14.41 vs. TES: 12.48±9.13, P =0.031). No significant difference was noted between the 2 groups in defecation difficulty, stool character, and the use of rescue medicine.

CONCLUSIONS

For the treatment of severe chronic constipation, EA performed better than TES in long-term follow-up and improving the quality of life. TES could be a better choice for patients with severe chronic constipation who are afraid of acupuncture because it is noninvasive. Well-designed and more rigorous clinical trials with larger sample sizes are needed.

Transcutaneous Electrical Acustimulation Improves Irritable Bowel Syndrome With Constipation by Accelerating Colon Transit and Reducing Rectal Sensation Using Autonomic Mechanisms

INTRODUCTION

Slow colon transit and visceral hypersensitivity are recognized as major pathophysiological mechanisms in irritable bowel syndrome with constipation (IBS-C). However, there is a lack of therapies targeting both abdominal pain and colonic motility. This study was designed to investigate the long-term effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) in patients with IBS-C.

METHODS

Fifty-two patients with IBS-C were randomized into 2 groups: daily TEA for 4 weeks (n = 26) and daily sham-TEA for 4 weeks (n = 26). The number of complete spontaneous bowel movements per week (CSBMs/week, primary outcome), Irritable Bowel Syndrome Severity Scoring System, Patient Assessment of Constipation Quality of Life, visual analog scale (VAS) pain score, colonic transit time, and anorectal physiology were evaluated before treatment and at the end of the treatment. Colonic transit was assessed with radiopaque markers. Electrocardiograms were recorded for assessing autonomic functions.

RESULTS

(i) TEA improved constipation and abdominal pain. After the treatment, the number of CSBMs/week during the last week in the TEA group was higher than that in the sham-TEA group (3.5 ± 1.6 vs 2.3 ± 0.6, P = 0.002). Similar effects were also noted in the visual analog scale pain score ( P = 0.002) and Irritable Bowel Syndrome Severity Scoring System score ( P = 0.025). In addition, there was a significant improvement in the quality of life of patients with constipation. The Patient Assessment of Constipation Quality of Life total score was significantly decreased in the TEA group ( P = 0.004). (ii) Compared with sham-TEA, TEA improved colon transit ( P = 0.002) and increased the threshold of rectal sensation (desire to defecate, P = 0.004; maximum tolerability, P &lt; 0.001). (iii) TEA increased vagal activity, compared with sham-TEA ( P &lt; 0.05); at the end of the treatment, the vagal activity was significantly correlated with colon transit and the CSBMs/week.

DISCUSSION

TEA improves constipation and symptoms of IBS by accelerating colon transit and reducing rectal sensation, possibly mediated by using the autonomic mechanisms.

Transcutaneous Electrical Acustimulation Improves Constipation by Enhancing Rectal Sensation in Patients With Functional Constipation and Lack of Rectal Sensation

INTRODUCTION

Reduced rectal sensation is involved in the pathophysiology of constipation. The aim of this study was to investigate the effects of transcutaneous electrical acustimulation (TEA) at acupuncture point ST36 on constipation and rectal sensation as well as autonomic functions in patients with constipation and reduced rectal sensation.

METHODS

In an acute study, anorectal motility and sensation tests were performed in constipation patients (N = 53) who were treated with TEA at ST36 or sham points. In a chronic study, patients (N = 18) underwent 2 weeks of TEA or sham-TEA in a crossover design.

RESULTS

Chronic TEA increased spontaneous bowel movements (3.72 vs 2.00 per week with sham-TEA, P < 0.0001) and significantly reduced constipation symptoms and increased quality of life in comparison with sham-TEA (P < 0.05). Acute TEA reduced the sensation threshold in response to rectal distention for the urge of defecation and maximum tolerable volume (P < 0.05, vs baseline); chronic TEA reduced the sensation thresholds for first sensation and desire of defecation, and decreased the threshold volume to an elicit rectal anal inhibitory reflex (P < 0.05). Both acute and chronic TEA increased parasympathetic activity (P < 0.05).

DISCUSSION

TEA at ST36 improves chronic constipation by enhancing rectal sensation possibly mediated by the reinforcement of parasympathetic activity in patients with functional constipation and reported lack/absence of rectal sensation.

Integrative effects of transcutaneous electrical acustimulation on abdominal pain, gastrointestinal motility, and inflammation in patients with early-stage acute pancreatitis

BACKGROUND/AIMS

Gastrointestinal (GI) dysmotility in acute pancreatitis (AP) aggravates inflammation and results in severe complications. This study aimed to explore effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) on abdominal pain, GI dysmotility, and inflammation in AP patients.

METHODS

Forty-two AP patients were blindly randomized to receive TEA (n = 21) at acupoints PC6 and ST36 or Sham-TEA (n = 21) at sham points for 2 days. Symptom scores, gastric slow waves, autonomic functions (assessed by spectral analysis of heart rate variability), circulatory levels of motilin, ghrelin, and TNF-α were measured before and after the treatment. Sixteen healthy controls (HCs) were also included without treatment for the assessment of gastric slow waves and biochemistry.

KEY RESULTS

Compared with Sham-TEA, TEA decreased abdominal pain score (2.57 ± 1.78 vs. 1.33 ± 1.02, p < 0.05), bloating score (5.19 ± 1.21 vs. 0.76 ± 0.99, p < 0.001), the first defecation time (65.79 ± 19.51 h vs. 51.38 ± 17.19 h, p < 0.05); TEA, but not Sham-TEA, improved the percentage of normal gastric slow waves by 41.6% (p < 0.05), reduced AP severity score (5.52 ± 2.04 vs. 3.90 ± 1.90, p < 0.05) and serum TNF-α (7.59 ± 4.80 pg/ml vs. 4.68 ± 1.85 pg/ml, p < 0.05), and upregulated plasma ghrelin (0.85 ± 0.96 ng/ml vs. 2.00 ± 1.71 ng/ml, p = 0.001) but not motilin (33.08 ± 22.65 pg/ml vs. 24.12 ± 13.95 pg/ml, p > 0.05); TEA decreased sympathetic activity by 15.0% and increased vagal activity by 18.3% (both p < 0.05).

CONCLUSIONS & INFERENCES

TEA at PC6 and ST36 administrated at early stage of AP reduces abdominal pain, improves GI motility, and inhibits inflammatory cytokine, TNF-α, probably mediated via the autonomic and ghrelin mechanisms.

Ameliorating effects and mechanisms of transcutaneous auricular vagal nerve stimulation on abdominal pain and constipation

BackgroundAbdominal pain and constipation are 2 main symptoms in patients with constipation-predominant irritable bowel syndrome (IBS-C). This study aimed to investigate the effects and possible mechanisms of transcutaneous auricular vagal nerve stimulation (taVNS) in patients with IBS-C.MethodsForty-two patients with IBS-C were randomized into a 4-week sham-taVNS or taVNS treatment. The primary outcomes were complete spontaneous bowel movements per week (CSBMs/week) and visual analog scale (VAS) for abdominal pain. High-resolution anorectal manometry (HRAM) was performed to evaluate anorectal motor and sensory function. Cytokines and brain gut peptides were analyzed in blood samples. ECG was recorded for the assessment of autonomic function.ResultsCompared with sham-taVNS, (a) taVNS increased CSBMs/week (P = 0.001) and decreased VAS pain score (P = 0.001); (b) improved quality of life (P = 0.020) and decreased IBS symptom score (P = 0.001); (c) improved rectoanal inhibitory reflex (P = 0.014) and improved rectal sensation (P < 0.04); (d) decreased a number of proinflammatory cytokines and serotonin in circulation; and (e) enhanced vagal activity (P = 0.040). The vagal activity was weakly correlated with the CSBMs/week (r = 0.391; P = 0.010) and the VAS pain score (r = -0.347; P = 0.025).ConclusionsNoninvasive taVNS improves both constipation and abdominal pain in patients with IBS-C. The improvement in IBS-C symptoms might be attributed to the integrative effects of taVNS on intestinal functions mediated via the autoimmune mechanisms.Trial registrationwww.chictr.org.cn, no. ChiCTR2000029644.FundingNational Natural Science Foundation of China (grant no. 81970538 for FL).

Transcutaneous auricular vagal nerve stimulation improves functional dyspepsia by enhancing vagal efferent activity

This study was designed to investigate whether transcutaneous auricular vagal nerve stimulation (taVNS) would be able to improve major pathophysiologies of functional dyspepsia (FD) in patients with FD. Thirty-six patients with FD (21 F) were studied in two sessions (taVNS and sham-ES). Physiological measurements, including gastric slow waves, gastric accommodation, and autonomic functions, were assessed by the electrogastrogram (EGG), a nutrient drink test and the spectral analysis of heart rate variability derived from the electrocardiogram (ECG), respectively. Thirty-six patients with FD (25 F) were randomized to receive 2-wk taVNS or sham-ES. The dyspeptic symptom scales, anxiety and depression scores, and the same physiological measurements were assessed at the beginning and the end of the 2-wk treatment. In comparison with sham-ES, acute taVNS improved gastric accommodation (P = 0.008), increased the percentage of normal gastric slow waves (%NSW, fasting: P = 0.010; fed: P = 0.007) and vagal activity (fasting: P = 0.056; fed: P = 0.026). In comparison with baseline, 2-wk taVNS but not sham-ES reduced symptoms of dyspepsia (P = 0.010), decreased the scores of anxiety (P = 0.002) and depression (P < 0.001), and improved gastric accommodation (P < 0.001) and the %NSW (fasting: P < 0.05; fed: P < 0.05) by enhancing vagal efferent activity (fasting: P = 0.015; fed: P = 0.048). Compared with the HC, the patients showed increased anxiety (P < 0.001) and depression (P < 0.001), and decreased gastric accommodation (P < 0.001) and %NSW (P < 0.001) as well as decreased vagal activity (fasting: P = 0.047). The noninvasive taVNS has a therapeutic potential for treating nonsevere FD by improving gastric accommodation and gastric pace-making activity via enhancing vagal activity.NEW & NOTEWORTHY Treatment of functional dyspepsia is difficult due to various pathophysiological factors. The proposed method of transcutaneous auricular vagal nerve stimulation improves symptoms of both dyspepsia and depression/anxiety, and gastric functions (accommodation and slow waves), possibly mediated via the enhancement of vagal efferent activity. This noninvasive and easy-to-implement neuromodulation method will be well received by patients and healthcare providers.

Auricular Vagal Nerve Stimulation Improves Constipation by Enhancing Colon Motility via the Central-Vagal Efferent Pathway in Opioid-Induced Constipated Rats

OBJECTIVES

Constipation and opioid-induced constipation (OIC) are common with limited treatment options. We investigated whether a noninvasive method of auricular vagal nerve stimulation (aVNS) could be used for treating OIC and explored its potential mechanisms and neural pathways in a rodent model of OIC.

MATERIALS AND METHODS

Sprague-Dawley were chronically implanted with one pair of auricular electrodes for aVNS. Sixteen rats were treated with loperamide for a week while another 16 rats received bilateral vagotomy, then randomly treated with aVNS or sham-aVNS for a week. In addition, eight normal rats were implanted with a polyethylene catheter in the proximal colon for assessing whole colon transit.

RESULTS

1) The number of fecal pellets and water content in feces increased after aVNS, compared with sham-aVNS. 2) aVNS accelerated colon transit and whole gut transit, compared with sham-aVNS. 3) In colon tissues, aVNS increased the protein expression of choline acetyltransferase, glial cell line-derived neurotrophic factor and the c-kit expression in myenteric interstitial cells of Cajal but decreased the protein expression of neural nitric oxide synthase (p < 0.05 for all, vs. sham-VNS). 4) The prokinetic effects of aVNS were abolished by both subdiaphragmatic vagotomy and atropine. 5) aVNS increased the c-fos expression in both nucleus tractus solitarius and dorsal motor nucleus of vagus, and increased vagal efferent activity (p < 0.05, vs. sham-VNS).

CONCLUSIONS

aVNS improves OIC by enhancing colon motility and restoring enteric neural functions mediated via the central and vagal efferent pathway.

Transcutaneous Acupoint Electrical Stimulation on Chemotherapy-Induced Constipation for Non-Small Cell Lung Cancer Patients: A Randomized Controlled Trial

Objective:

Chemotherapy-induced constipation (CIC) adversely affects the quality of life of non-small cell lung cancer (NSCLC) patients. This study aimed to investigate the clinical effects of transcutaneous acupoint electrical stimulation (TAES) on CIC.

Methods:

Sixty NSCLC patients who received chemotherapy at Hunan Cancer Hospital, Changsha, China, were assigned to the TAES (n = 30) or control (n = 30) group using Research Randomizer. In the TAES group, four acupoints, namely Tianshu, Quchi, Zusanli, and Shangjuxu, were stimulated six times a week, lasting for 4 weeks, while the control group received the usual care. The Bristol Stool Form Scale (BSFS) and the Constipation Assessment Scale (CAS) were used.

Results:

Both the BSFS and CAS scores for the experimental group were significantly higher than that for the control group (P = 0.004 and P < 0.001 separately).

Conclusions:

TAES was effective for alleviating constipation in NSCLC patients receiving chemotherapy and was a safe and practical nursing intervention.

Efficacy evaluation of acupuncture combined with Liujunzi Decoction in the treatment of functional dyspepsia: A protocol of randomized controlled trial

BACKGROUND

Functional dyspepsia (FD) is a common and frequently-occurring disease in internal medicine. It is known that Liujunzi decoction and acupuncture are widely used in the treatment of FD, but there are few studies on the combination of Liujunzi decoction and acupuncture in the treatment of FD, and its safety and efficacy are still controversial. Therefore, the purpose of this study is to evaluate the efficacy and safety of acupuncture combined with Liujunzi decoction in the treatment of FD.

METHODS

We designed a prospective randomized controlled trial. The study protocol was approved by the Clinical Research Ethics Committee of our hospital. Patients with FD were randomly assigned to the treatment group of acupuncture combined with Liujunzi Decoction (the experimental group) and the treatment group of Liujunzi Decoction (the control group) in a ratio of 1:1. Outcome indicators were Nepean Dyspepsia Index, the MOS item short from health survey, and adverse reactions. Finally, SPSS 18.0 software would be used for statistical analysis of the data.

DISCUSSION

This study will evaluate the efficacy and safety of acupuncture combined with Liujunzi Decoction in the treatment of FD and provide clinical basis for the use of acupuncture combined with Liujunzi Decoction in the treatment of FD.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/67GKN.

Optimized Tibial Nerve Stimulation Partially Reduces Visceral Hypersensitivity in Rats Mediated via Autonomic and Opioid Mechanisms

OBJECTIVES

The aim of this study was to investigate the therapeutic effect and possible mechanisms of tibial nerve stimulation (TNS) on visceral hypersensitivity in rats.

MATERIALS AND METHODS

1) The effects of TNS with five sets of parameters on visceral sensitivity in normal rats were evaluated by the assessment of abdominal electromyogram (EMG) and abdominal withdrawal reflex (AWR). 2) The effects and mechanisms of TNS with a special set of parameters (14 Hz, 330 μsec, and 40% motor threshold) were evaluated in acute visceral hypersensitivity rats induced by restraint stress and colonic hypersensitized rats induced by acetic acid during the neonatal stage assessed by the EMG, AWR, and the spectral analysis of heart rate variability derived from the electrocardiogram.

RESULTS

1) In normal rats, TNS did not show any effect on the visceromotor reflex. 2) In rats with restraint stress-induced hypersensitivity, TNS with the special set of parameters reduced AWR scores and EMG responses to rectal distention at a pressure of 20-60 mmHg (p < 0.05, vs. baseline for both AWR and EMG). Concurrently, TNS increased vagal activity and decreased sympathetic activity (p < 0.03 for both). 3) Similar effects were noted on the EMG (p < 0.05, vs. baseline) and AWR (p < 0.05 vs. baseline) with acute and chronic TNS in rats with chronic colonic hypersensitivity and the effects were blocked by naloxone.

CONCLUSIONS

TNS with parameters of 14 Hz, 330 μsec, and 40% motor threshold is effective in improving visceral hypersensitivity in rodent models of colonic hypersensitivity via the modulation of autonomic and opioid mechanisms.

Electroacupuncture at Zusanli (ST36) Repairs Interstitial Cells of Cajal and Upregulates c-Kit Expression in Rats with SCI-Induced Neurogenic Bowel Dysfunction

Background

Electroacupuncture (EA) could improve colonic transit activity in rats with neurogenic bowel dysfunction (NBD) caused by spinal cord injury (SCI). The function of interstitial cells of Cajal (ICCs) and c-Kit expression may play essential roles in this process. Material and Methods. Thirty-six Sprague Dawley rats were randomized to the sham group, the SCI group, or the SCI + EA group (bilateral Zusanli, 30 min/day, 14 days). Changes in the ultrastructural morphology of ICCs were observed. The c-Kit expression on different levels was analyzed by immunohistochemistry, Western blotting, and RT-qPCR, respectively.

Results

Abnormal morphology of ICCs and downregulation of the c-Kit expression occurred after SCI. While the number of ICCs was increased, the ultrastructural morphology was improved significantly in EA rats. They also showed better improvement in c-Kit expression at both protein and gene levels.

Conclusion

Abnormal ICCs in colon tissues and the downregulated expression of c-Kit could be observed after SCI. EA at Zusanli (ST36) could improve the colon function by repairing the morphology and increasing the number of ICCs and upregulating c-Kit expression.

Bioelectrical Signals for the Diagnosis and Therapy of Functional Gastrointestinal Disorders

Coordinated contractions and motility patterns unique to each gastrointestinal organ facilitate the digestive process. These motor activities are coordinated by bioelectrical events, sensory and motor nerves, and hormones. The motility problems in the gastrointestinal tract known as functional gastrointestinal disorders (FGIDs) are generally caused by impaired neuromuscular activity and are highly prevalent. Their diagnosis is challenging as symptoms are often vague and difficult to localize. Therefore, the underlying pathophysiological factors remain unknown. However, there is an increasing level of research and clinical evidence suggesting a link between FGIDs and altered bioelectrical activity. In addition, electroceuticals (bioelectrical therapies to treat diseases) have recently gained significant interest. This paper gives an overview of bioelectrical signatures of gastrointestinal organs with normal and/or impaired motility patterns and bioelectrical therapies that have been developed for treating FGIDs. The existing research evidence suggests that bioelectrical activities could potentially help to identify the diverse etiologies of FGIDs and overcome the drawbacks of the current clinically adapted methods. Moreover, electroceuticals could potentially be effective in the treatment of FGIDs and replace the limited existing conventional therapies which often attempt to treat the symptoms rather than the underlying condition.

Ameliorating Effects of Transcutaneous Electrical Acustimulation at Neiguan (PC6) and Zusanli (ST36) Acupoints Combined with Adaptive Biofeedback Training on Functional Outlet Obstruction Constipation

Background

Stimulant laxatives are still considered the most common treatment for functional outlet obstruction constipation (FOOC). However, the effectiveness of laxatives is unsatisfactory, and the long-term use of laxatives may cause certain adverse events. With this in mind, it is, however, paramount that novel complementary treatment(s) and/or other forms of alternative medicine are adequately investigated.

Aims

The study aims to explore the effects and potential mechanism(s) of transcutaneous electrical acustimulation (TEA) combined with adaptive biofeedback training (ABT) on FOOC.

Methods

A total of forty-five patients with FOOC were recruited and were randomly assigned to receive either Macrogol 4000 Powder (MAC, 10 g bid) (group A, n = 15) only, ABT + MAC + Sham-TEA (group B, n = 15), or TEA + ABT + MAC (group C, n = 15) in a six-week study. Individual patients' constipation-symptoms (PAC-SYM) and constipation-quality of life (PAC-QOL) were both assessed and scored. Serum acetylcholine (Ach) and nitric oxide (NO) were measured from drawn blood samples while individual patients' heart rate variability (HRV) was calculated at baseline and after each corresponding therapy. Anorectal manometry and balloon expulsion test were both performed before and after treatment.

Results

Firstly, participants in group C had significantly lower scores of PAC-SYM, PAC-QOL, and a decreased anal defecating pressure (ADP) as compared to participants in group B (all p < 0.050). These results, however, suggest the TEAs effect. Secondly, the low-frequency band (LF)/(LF + HF) ratio in groups B and C were decreased as compared to group A (p=0.037, p=0.010, respectively) regarding HRV. On the other hand, the high-frequency band (HF)/(LF + HF) ratio in groups B and C showed an opposite outcome. Finally, the serum Ach in groups B and C was significantly higher as compared to group A (p=0.023, p=0.012, respectively). Of significant importance, the serum NO in groups B and C were notably low as compared to group A (p=0.001, p < 0.001, respectively).

Conclusions

TEA, combined with ABT, effectively improves constipation symptoms as well as QOL in FOOC patients. It is, however, achieved by decreasing ADP, which mechanisms are mediated via the autonomic and enteric mechanisms.

Sacral nerve stimulation ameliorates colonic barrier functions in a rodent model of colitis

BACKGROUND

The mucosal barrier damage is recognized as one of the key factors in the pathogenesis of colitis. While sacral nerve stimulation (SNS) was reported to have therapeutic potential for colitis, its mechanisms of actions on colonic permeability remained largely unknown.

METHODS

In this study, colitis was induced by intrarectal administration of TNBS in rats. Five days later, they were treated with SNS or sham-SNS for 10 days. The effects of SNS on colonic permeability were assessed by measuring the expression of tight-junction proteins involved in regulating permeability and the FITC-dextran test. The mechanism of actions of SNS was investigated by studying the function of the enteric nervous system (ENS) cells and analyzing the autonomic nervous system.

KEY RESULTS

SNS decreased the disease activity index, microscopic and macroscopic scores, myeloperoxidase activity, and pro-inflammatory cytokines (TNF-α, IL-6). SNS increased the expression of Zonula Occludens-1, Occludin, Claudin-1, and Junctional adhesion molecule-A in the colon tissue. The FITC-dextran test showed that the colonic permeability was lower with SCS than sham-SNS. SNS increased ChAT, pancreatic polypeptide, and GDNF and reduced norepinephrine NGF, sub-P, and mast cell overactivation in the colon tissue. Concurrently, SNS increased acetylcholine in colon tissues and elevated vagal efferent activity.

CONCLUSIONS & INFERENCES

SNS ameliorates colonic inflammation and enhances colonic barrier function with the proposed mechanisms involving the increase in parasympathetic activity and modulation of the activity of the ENS and immune system, including mast cells.

The role of tibial nerve stimulation for enhanced postoperative recovery after colorectal surgery: a double-blind, parallel-group, randomized controlled trial

BACKGROUND

Postoperative ileus (POI) is the most common cause of prolonged hospital stay following abdominal surgery, despite an optimized enhanced recovery after surgery (ERAS) program. The aim of the study was to evaluate the role of postoperative transcutaneous electrical tibial nerve stimulation (TTNS) in the recovery of bowel function and in shortening hospital stay after colonic resection.

METHODS

Patients having elective laparoscopic colonic surgery within an ERAS program at our institution between June 2016 and June 2019 were enrolled and randomly assigned to a treatment protocol with TTNS or sham electrical stimulation. The primary endpoint was the time of recovery of gastrointestinal motility, measured as the first passage of stool. Secondary endpoints included: first passage of flatus, length of hospital stay, and complication rate related to the use of TTNS.

RESULTS

One hundred and seventy patients who had right hemicolectomy (median age 71 years (range 43-89 years); 47.5% women) and 170 patients who had left colectomy (median age 67 years range (37-92 years); 41.5% women) were enrolled. The only factor significantly affected by TTNS was time to first passage of flatus after right hemicolectomy (reduced from 46 to 33 h, p = 0.04). However, if only patients with low compliance to early oral nutrition (63 of 340; 18.5%) were considered, a statistically significant difference in time until first flatus (p < 0.01) and first bowel movement (p < 0.0001) and a shorter time until discharge (median 5 vs 7 days) were found in both left and right colectomies groups, respectively.

CONCLUSIONS

TTNS may have a positive effect on gastrointestinal tract motility and recovery from POI after colorectal surgery in a selected group, who has low compliance with an ERAS program, without increasing the risk of complications.

Transcutaneous Neuromodulation improved inflammation and sympathovagal ratio in patients with primary biliary ssscholangitis and inadequate response to Ursodeoxycholic acid: a pilot study

Background

At present, ursodeoxycholic acid (UDCA) is internationally recognized as a therapeutic drug in clinic. However, about 40% Primary Biliary Cholangitis (PBC) patients are poor responders to UDCA. It has been demonstrated that Transcutaneous Neuromodulation (TN) can be involved in gut motility, metabolism of bile acids, immune inflammation, and autonomic nerve. Therefore, this study aimed to explore the effect of TN combined with UDCA on PBC and related mechanisms.

Methods

According to inclusion and exclusion criteria, 10 healthy volunteers and 15 PBC patients were recruited to control group and TN group, respectively. PBC patients were alternately but blindly assigned to group A (TN combined with UDCA) and group B (sham-TN combined with UDCA), and a crossover design was used. The TN treatment was performed via the posterior tibial nerve and acupoint ST36 (Zusanli) 1 h twice/day for 2 weeks. T test and nonparametric test were used to analyze the data.

Results

1. TN combined with UDCA improved the liver function of PBC patients shown by a significant decrease of alkaline phosphatase and gamma-glutamyltransferase (γ-GT) (P < 0.05). 2. The treatment also decreased serum IL-6 levels (P < 0.05), but not the level of Tumor Necrosis Factor-α, IL-1β or IL-10. 3. TN combined with UDCA regulated autonomic function, enhanced vagal activity, and decreased the sympathovagal ratio assessed by the spectral analysis of heart rate variability (P < 0.05). 4. There was no change in 13 bile acids in serum or stool after TN or sham-TN.

Conclusions

TN cssombined with UDCA can significantly improve the liver function of PBC patients. It is possibly via the cholinergic anti-inflammatory pathway. TN might be a new non-drug therapy for PBC. Further studies are required.

Trial registration

The study protocol was registered in Chinese Clinical Trial Registry (number ChiCTR1800014633) on 25 January 2018.

Transcutaneous Neuromodulation at ST36 (Zusanli) is More Effective than Transcutaneous Tibial Nerve Stimulation in Treating Constipation

BACKGROUND AND GOALS

Combined transcutaneous neuromodulation (TN) at acupoint ST36 (Zusanli) and TN at the posterior tibial nerve (PTN) has been reported effective in treating functional constipation. This study was designed to compare the effectiveness of TN between these 2 points.

MATERIALS AND METHODS

Eighteen functional constipation patients (M/F: 9/9) were recruited to participate in a cross-over study with a 2-week TN at ST36 and a 2-week TN at PTN. A bowel movement diary, and the questionnaires of Patient Assessment of Constipation Symptom (PAC-SYM) and Constipation Quality of Life (PAC-QoL) were completed; anorectal manometry and spectral analysis of heart rate variability for assessing the autonomic function were performed.

RESULTS

(1) Both TN at ST36 and TN at PTN improved constipation-related symptoms (PAC-SYM scores on pre-TN vs. post-TN: 1.4±0.1 vs. 0.6±0.1 for ST36, 1.4±0.1 vs. 0.9±0.1 for PTN, both P≤0.001). (2) TN at ST36, but not TN at PTN, increased the number of weekly spontaneous bowel movements (0.9±0.2 pre-TN vs. 3.5±0.7 post-TN, P<0.001) and decreased the total PAC-QoL score. TN at ST36 was more potent than TN at PTN in improving the PAC-SYM score (decrement 0.8±0.1 vs. 0.5±0.1, P<0.05). (3) TN at ST36 rather than TN at PTN resulted in a reduction in sensation thresholds, including rectal distention for urge (134.1±14.3 mL pre-TN vs. 85.6±6.5 mL post-TN, P<0.01) and maximum tolerance (P<0.05). (4) Both TN at ST36 and TN at PTN significantly increased vagal activity and decreased sympathetic activity (P<0.05).

CONCLUSIONS

TN at ST36 is more potent than TN at PTN in treating constipation and improving constipation-related symptoms and rectal sensation.

Transcutaneous Electrical Acustimulation Improves Gastrointestinal Disturbances Induced by Transcatheter Arterial Chemoembolization in Patients With Liver Cancers

BACKGROUND

Gastrointestinal (GI) disturbances occur in patients who receive chemotherapy via transcatheter arterial chemoembolization (TACE) and could last for an extended period of time in some cases. Antiemetic drugs have a potential risk of developing hepatic failure and are ineffective for delayed nausea and emesis. Transcutaneous electrical acustimulation (TEA) has recently been reported to exert antiemetic and prokinetic effects, but it is unknown whether it has an ameliorating effect on TACE-induced GI disturbances.

AIM

This study was designed to evaluate effects and mechanisms of noninvasive TEA on GI symptoms in patients treated with TACE.

MATERIALS AND METHODS

Seventy-four patients with liver cancers (eighteen female; age 63.4 ± 1.1 years) scheduled for TACE were randomized to TEA (n = 37) or sham-TEA (n = 37). TEA was performed via acupoints, ST36 and PC6 using parameters previously optimized for GI motility (1 h, bid) from the postoperative day 0 (POD0) to POD2. Sham-TEA was performed using the same parameters via non-acupoints. Symptom questionnaires were completed daily. The electrogastrogram (EGG) and electrocardiogram (ECG) were recorded in the fasting state for 30 mins to assess gastric slow waves and autonomic functions, respectively, before and after the 3-day treatment.

RESULTS

1) In the acute phase (<24 h), TEA showed no effects on any of GI symptoms, compared with sham-TEA. 2) In the delayed phase (>24 h), TEA, compared with sham-TEA, decreased the percentage of patients who experienced nausea on POD3 (0% vs. 13.5%, p = 0.021), the nausea score on POD3 (p = 0.022), the anorexia score on POD2 (p = 0.040) and POD3 (p = 0.004), and the bloating score (POD1-3: p < 0.01). 3) In comparison with sham-TEA, TEA increased the number of spontaneous bowel movements (p = 0.001) and the Bristol score of the first stool (p = 0.014) and decreased the number of patients with the use of laxatives (p = 0.022). 4) Physiologically, the 3-day TEA but not sham-TEA increased the percentage of normal gastric slow waves (p < 0.001) and vagal activity (p = 0.006). The vagal activity was negatively correlated with the anorexia score (r = -0.267, p = 0.026). It was found that the sympathovagal ratio and tumor size>5 cm were independent risk factors predicting the occurrence of nausea in patients after TACE.

CONCLUSION

TEA improves major TACE-induced GI disturbances in the delayed phase, including nausea, bloating, impaired gastric pace-making activity, and constipation in patients with liver cancers via the autonomic pathway.

Poststroke Constipation Is Associated With Impaired Rectal Sensation

OBJECTIVES

Constipation is prevalent in individuals after stroke. However, the pathophysiological mechanisms of poststroke constipation remain unclear. This study was designed (i) to investigate the difference in anorectal motility and rectal sensation among stroke patients with constipation, stroke patients without constipation, and healthy controls (HC), (ii) to evaluate the impact of stroke sites on constipation and rectal sensation, (iii) to explore the role of autonomic functions, and (iv) to determine the independent risk factors for poststroke constipation.

METHODS

Seventy-one stroke patients and 24 HC were recruited. General information, clinical characteristics, and relevant questionnaires were collected. Meanwhile, an anorectal manometry test was performed to assess functions of anorectal motility and rectal sensation, and an electrocardiogram was recorded to evaluate autonomic functions.

RESULTS

(i) Constipation patients exhibited increased rectal sensation thresholds, compared with patients without constipation or HC (P < 0.001). Almost no difference was detected in anorectal motility parameters among 3 groups. Constipation-associated clinical characteristics, such as spontaneous bowel movements, were weakly or moderately correlated with rectal sensation thresholds (P < 0.05 to P < 0.001 for various parameters). (ii) Patients with brainstem lesions had increased prevalence of constipation and first sensation threshold, compared with patients without brainstem lesions (P = 0.045, P = 0.025, respectively). (iii) There was a weak positive correlation between sympathetic activity and stroke severity and a weak negative one between vagal activity and stroke severity. Rectal sensation thresholds were positively and weakly correlated with sympathetic activity but negatively with vagal activity. (iv) The desire of defecation threshold and the physical activity were independent risk factors for poststroke constipation (P = 0.043, P = 0.025, respectively).

DISCUSSION

Poststroke constipation is characterized by elevated thresholds for rectal sensation, rather than altered anorectal motility. Patients with brainstem lesions are predisposed to constipation possibly because of the disruption of afferent pathway from the rectum to the brain. Moreover, the desire of defecation threshold and the physical activity level are factors independently associated with poststroke constipation.

Ameliorating Effects and Autonomic Mechanisms of Transcutaneous Electrical Acustimulation in Patients With Gastroesophageal Reflux Disease

BACKGROUND/AIM

Gastric dysmotility is one of pathophysiologies of gastroesophageal reflux disease (GERD). The aim of this study was to investigate the effects of transcutaneous electrical acustimulation (TEA) on gastric accommodation and gastric slow waves, and evaluate possible mechanisms in patients with GERD.

METHODS

Thirty patients were studied in two randomized sessions of sham-TEA and TEA with the measurements of esophageal high-resolution manometry (HRM), gastric accommodation assessed by a nutrient-drinking test, electrogastrogram (EGG), electrocardiogram (ECG), and postprandial dyspeptic symptoms.

RESULTS

Compared with sham-TEA, TEA improved nutrient drinking-induced fullness (42.0 ± 3.3 vs. 31.0 ± 3.5, P = 0.003) at 10 min after the drink, and belching right after the drink (22.0 ± 4.6 vs. 11.7 ± 3.1, P = 0.012) and at 10 min (16.0 ± 3.8 vs. 3.0 ± 1.5, P = 0.002) after the drink. TEA also improved gastric accommodation (954 ± 37 mL vs. 857 ± 47 mL, P = 0.001) and normalized maximal drink-induced impairment in gastric slow waves. Concurrently, TEA enhanced vagal activity assessed from spectral analysis of heart rate variability in the postprandial state (0.42 ± 0.03 vs. 0.49 ± 0.04, P = 0.039). The vagal activity was positively correlated with the percentage of normal slow waves (r = 0.528; P = 0.003) and negatively correlated with the regurgitation score (r = -0.408, P = 0.025).

CONCLUSIONS

Acute TEA increases gastric accommodation, improves gastric slow waves, and reduces postprandial fullness and belching, possibly mediated via the vagal mechanisms.

Use of Bioelectronics in the Gastrointestinal Tract

Gastrointestinal (GI) motility disorders are major contributing factors to functional GI diseases that account for >40% of patients seen in gastroenterology clinics and affect >20% of the general population. The autonomic and enteric nervous systems and the muscles within the luminal GI tract have key roles in motility. In health, this complex integrated system works seamlessly to transport liquid, solid, and gas through the GI tract. However, major and minor motility disorders occur when these systems fail. Common functional GI motility disorders include dysphagia, gastroesophageal reflux disease, functional dyspepsia, gastroparesis, chronic intestinal pseudo-obstruction, postoperative ileus, irritable bowel syndrome, functional diarrhea, functional constipation, and fecal incontinence. Although still in its infancy, bioelectronic therapy in the GI tract holds great promise through the targeted stimulation of nerves and muscles.

Electroacupuncture via chronically implanted electrodes improves gastrointestinal motility by balancing sympathovagal activities in a rat model of constipation

Electroacupuncture (EA) has been reported for treating constipation in clinical studies. However, little is known of the possible mechanisms involved in the prokinetic effect of EA. The aim of this study was to investigate the effects and underlying autonomic mechanisms of EA via chronically implanted electrodes for constipation in rat induced by Loperamide (Lop). Lop was given to regular rats to induce constipation. EA was performed via a pair of electrodes chronically implanted at bilateral acupoint ST-36. Feces characteristics, gastric emptying, small intestinal transit, distal colon transit time (dCTT), and whole gut transit time (WGTT) were measured in various sessions with EA or sham EA in rats with constipation induced by Lop. Heart rate variability (HRV) derived from the electrocardiogram was analyzed to evaluate autonomic functions. The number of fecal pellets was reduced by 27% with Lop (P < 0.01) and normalized by 7-day EA. Similar results were also observed in pellet weight. In normal rats compared with sham EA, EA shortened dCTT by 74% (P < 0.05 vs. sham EA), increased small intestinal transit by 28% (P < 0.01) and gastric emptying by 27% (P < 0.05), and accelerated whole gut transit by 14% (P < 0.05). In Lop-treated rats, the dCTT and WGTT were prolonged by Lop and normalized by EA. Lop significantly decreased vagal activity and increased sympathetic nerve activity; however, EA reversed these effects. EA at ST-36 via chronically implanted electrodes improves Lop-induced constipation by enhancing GI motility via the autonomic mechanisms. NEW & NOTEWORTHY The findings of the present study suggest that the proposed electroacupuncture (EA) may have great therapeutic potential for treating patients with opioid-induced constipation. It was demonstrated that EA at ST-36 improved transit of every organ along the gut mediated via the autonomic mechanisms in normal rats and rats with Lop-induced constipation. It is advised to administrate EA daily instead of two or three times weekly as reported in most of the clinical studies.

Preventive effects of transcutaneous electrical acustimulation on ischemic stroke-induced constipation mediated via the autonomic pathway

The aim of this study was to explore the preventive effect and possible mechanisms of transcutaneous electrical acustimulation (TEA) on stroke-induced constipation. A total of 86 ischemic stroke patients were randomly allocated to 2-wk TEA or sham-TEA group. Bowel dairy and Bristol Stool Form Scale were recorded daily. Constipation and dyspeptic symptom assessment was performed at the end of the 14-day treatment. Electrocardiogram was recorded for the assessment of autonomic function. The correlation between autonomic function at admission and stroke severity was assessed. The univariate and multivariate regression analyses were performed to investigate the risk factors for stroke-induced constipation. The cumulative incidence of stroke-induced constipation was 68.2% at the acute stage. Sympathetic nerve activity at admission was positively correlated with stroke severity ( R = 0.47, P < 0.001). Sympathetic nerve activity and stroke severity were independent risk factors for stroke-induced constipation. TEA decreased cumulative incidence of stroke-induced constipation (42.9 vs. 68.2%, P = 0.029). TEA significantly increased frequency of bowel movements (4.5 vs. 5.5, P = 0.001) and spontaneous bowel movements (3.0 vs. 4.5, P = 0.003) per week. TEA decreased straining defecations (0.2 vs. 0, P < 0.001) and laxative use (1 vs. 0, P < 0.001). TEA improved stool consistency and patients' quality of life ( P < 0.05, resp.). TEA increased vagal activity ( P < 0.001 vs. baseline) and decreased sympathetic activity ( P < 0.001 vs. baseline). Ischemic stroke patients are predisposed to autonomic function imbalance. TEA was effective in the prevention of stroke-induced constipation, and the effect was possibly mediated via the autonomic function. NEW & NOTEWORTHY This study illustrated that the brain-gut dysfunction, primarily autonomic function imbalance, was correlated with the stroke-induced constipation. This was the first study to report that transcutaneous electrical acustimulation had a preventive effect on stroke-induced constipation, suggesting a potential novel therapy for bowel problem management. The effect was possibly mediated via the autonomic function.

Needleless Transcutaneous Electrical Acustimulation: A Pilot Study Evaluating Improvement in Post-Operative Recovery

BACKGROUND

Functional gastrointestinal disturbance occurs after abdominal surgeries and could last for an extended period of time in some cases. This study was designed (1) to evaluate the effects of needleless transcutaneous electrical acustimulation (TEA) on postoperative recovery, and (2) to investigate the mechanisms involving autonomic function in postoperative patients after removal of gastrointestinal cancers.

METHODS

Forty-two patients (33 male, age: 69.5 ± 1.5 years) scheduled for abdominal surgical removal of gastrointestinal cancers were randomized to TEA (n = 21) and sham-TEA (n = 21). TEA was performed via acupoints ST36 and PC6 1 h twice daily from the postoperative day (POD) 1 to day 3. Sham-TEA was performed at non-acupoints.

RESULTS

(1) TEA improved major postoperative symptoms by about 30%, including a reduction in time to defecation by 31.7% (P < 0.01 vs. sham-TEA), time to first flatus by 35.9% (P < 0.001), time to ambulation by 42.8% (P < 0.01), time to resuming diet by 26.5% (P < 0.01) and hospital stay by 30% (P < 0.05) as well as pain score by 50% (P < 0.01). (2) TEA significantly increased vagal activity (P < 0.001) and decreased sympathetic activity on POD 4 (P < 0.001) compared with POD 1 as well as the serum level of NE (P < 0.05). (3) The vagal activity, high frequency assessed from the spectral analysis of heart rate variability, was negatively correlated with time to resuming diet, whereas the sympathetic measurement, serum norepinephrine was positively correlated with time to resuming diet and time to flatus. (4) TEA but not sham-TEA decreased TNF-α by 17.4% from POD 1 to POD 4. (5) TEA was an independent predictor of a shorter hospital stay.

CONCLUSIONS

Needleless TEA improves major postoperative symptoms by enhancing vagal and suppressing sympathetic activities.

Electroacupuncture treatments for gut motility disorders

Functional gastrointestinal (GI) diseases are common and there are patients who are refractory to medical therapies as not all treatments work in all patients. Consequently, a large number of patients with functional GI diseases use complementary and alternative medicine, such as acupuncture or electroacupuncture (EA). In this issue, Zheng et al. reported interesting results of a multi-center placebo-controlled clinical study on the use of EA for treating refractory functional dyspepsia; another study reported a multi-center clinical trial on EA for chronic functional constipation; Liang et al. studied mechanisms of EA involving enteric nervous system and neurotransmitters in treating constipation in rats. While controversial reports are available in the literature, EA with appropriate methodologies as shown in these recent studies is believed to be effective in treating certain functional GI diseases. In this mini-review, a number of clinical studies, including those included in this issue on the use of EA for treating gastro-esophageal reflux, functional dyspepsia, irritable bowel syndrome, and constipation are reviewed. Some critically important issues, such as the choice of stimulation parameters for EA, the administration frequency of the therapy, and the appropriate choice of placebo for clinical research are also discussed. Mechanisms of action involved in the therapeutic effects of EA for gut dysmotility and future research directions are also presented.

Home-Based Transcutaneous Neuromodulation Improved Constipation via Modulating Gastrointestinal Hormones and Bile Acids

This study aims to investigate the role of transcutaneous neuromodulation (TN) on the regulation of gastrointestinal hormones and bile acids in patients with functional constipation (FC). Twenty FC patients were treated with TN for four weeks. The effects of TN on symptoms were evaluated by questionnaires. Plasma levels of serotonin (5-HT), motilin, somatostatin, and vasoactive intestinal peptide (VIP) were measured by ELISA and 12 individual bile acids assayed by liquid chromatography tandem mass spectrometry. Results were as follows. (1) TN treatment increased the frequency of spontaneous bowel movement, improved the Bristol Stool Score, and reduced Patient Assessment of Constipation Symptom score and Patient Assessment of Constipation Quality of Life score. (2) FC patients showed decreased plasma levels of 5-HT, motilin, and VIP and an increased plasma level of somatostatin (P < 0.05). Four-week TN treatment increased plasma levels of 5-HT and motilin and decreased the plasma level of somatostatin in the FC patients (P < 0.05). (3) Taurocholic deoxycholate, taurocholic acid, and taurocholic lithocholic acid were increased in the FC patients (P < 0.005) but reduced by TN treatment (P < 0.05). This study has suggested that the therapy may improve the symptoms of FC by alleviating the disorders of gastrointestinal hormones and bile acids.

Normative Values for Colonic Transit Time and Patient Assessment of Constipation in Adults With Functional Constipation: Systematic Review With Meta-Analysis

Availability of normative patient outcome data may assist in designing experiments and estimating sample sizes. The purpose of this review was to determine normative ranges for colonic transit time (CTT), Patient Assessment of Constipation-Symptoms (PAC-SYM), and Patient Assessment of Constipation-Quality of Life (PAC-QOL) in adults diagnosed with functional constipation per Rome III guidelines. Pooled estimates were derived from random-effects meta-analysis. Meta-regression was used to explore sources of heterogeneity among studies. A total of 24 studies (3786 patients) were included in the review. In 10 studies with 1119 patients, pooled CTT was 58 hours (95% confidence interval [CI]: 50-65 hours). Publication bias was not evident (Egger P = .51); heterogeneity was high (I² = 92%, P < .001). In meta-regression, geographical location explained 57% of the between-study variance, with CTT significantly longer in studies conducted in Europe (71 hours) compared with Asia (49 hours) or the Americas (44 hours). In 9 studies with 2061 patients, pooled PAC-SYM was 1.70 (95% CI: 1.58-1.83). Publication bias was not evident (Egger P = .44). Heterogeneity was high (I² = 90%, P < .001); however, no study or patient factor influenced PAC-SYM in meta-regression. In 12 studies with 1805 patients, pooled PAC-QOL was 1.97 (95% CI: 1.70-2.24). Publication bias was not evident (Egger P = .28); heterogeneity was high (I² = 98%, P < .001). In meta-regression, age explained 52% of the between-study variance, with older age associated with lower PAC-QOL scores. Overall, in adults diagnosed with functional constipation per Rome III criteria, significant heterogeneity in CTT, PAC-SYM, and PAC-QOL exists among studies. Variability among studies may be explained by geography and patient factors.

Comprehensive evaluation of gene expression signatures in response to electroacupuncture stimulation at Zusanli (ST36) acupoint by transcriptomic analysis

Background

Electroacupuncture (EA) has been applied to treat and prevent diseases for years. However, molecular events happened in both the acupunctured site and the internal organs after EA stimulation have not been clarified.

Methods

Here we applied transcriptomic analysis to explore the gene expression signatures after EA stimulation. Mice were applied EA stimulation at ST36 for 15 min and nine tissues were collected three hours later for microarray analysis.

Results

We found that EA affected the expression of genes not only in the acupunctured site but also in the internal organs. EA commonly affected biological networks involved in cytoskeleton and cell adhesion, and also regulated unique process networks in specific organs, such as γ-aminobutyric acid-ergic neurotransmission in brain and inflammation process in lung. In addition, EA affected the expression of genes related to various diseases, such as neurodegenerative diseases in brain and obstructive pulmonary diseases in lung.

Conclusions

This report applied, for the first time, a global comprehensive genome-wide approach to analyze the gene expression profiling of acupunctured site and internal organs after EA stimulation. The connection between gene expression signatures, biological processes, and diseases might provide a basis for prediction and explanation on the therapeutic potentials of acupuncture in organs.

Circulating motilin, ghrelin, and GLP-1 and their correlations with gastric slow waves in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) commonly complain upper gastrointestinal (GI) symptoms, especially anorexia. Hemodialysis (HD) has been noted to improve GI symptoms; however, the underlying mechanisms are unclear. This study was designed 1) to study effects of HD on GI symptoms and gastric slow waves; and 2) to investigate possible roles of ghrelin and glucagon-like peptide-1 (GLP-1): the study recruited 13 healthy controls, 20 CKD patients without HD (CKD group), and 18 CKD patients with HD (HD group). Dyspeptic symptoms, autonomic functions, gastric slow waves, and plasma level of ghrelin and GLP-1 were analyzed. First, the CKD patients with HD showed markedly lower scores of anorexia (0.6 ± 0.2 vs. 3.2 ± 0.4, P < 0.001) compared with patients without HD. Second, the CKD group but not HD group showed a significant reduction (25.6%) in the percentage of normal gastric slow waves, compared with controls. Third, the CKD group exhibited a significantly lower ghrelin level compared with the HD group (26.8 ± 0.9 vs. 34.1 ± 2.3 ng/l, P < 0.02) and a higher GLP-1 level (29.4 ± 2.8 vs. 20.0 ± 2.1 pmol/l, P < 0.05) compared with controls. Moreover, the percentage of normal slow waves was positively correlated with ghrelin (r = 0.385, P = 0.019) but negatively correlated with GLP-1 (r = -0.558, P < 0.001) in all CKD patients. Hemodialysis improves upper GI symptoms and gastric slow waves in CKD patients. An increase in ghrelin and a decrease in GLP-1 might be involved in the HD-induced improvement in gastric slow waves.

Electrical therapies for gastrointestinal motility disorders

Gastrointestinal (GI) motility disorders are common in clinical settings, including esophageal motility disorders, gastroesophageal reflux disease, functional dyspepsia, gastroparesis, chronic intestinal pseudo-obstruction, post-operative ileus, irritable bowel syndrome, diarrhea and constipation. While a number of drugs have been developed for treating GI motility disorders, few are currently available. Emerging electrical stimulation methods may provide new treatment options for these GI motility disorders. Areas covered: This review gives an overview of electrical therapies that have been, and are being developed for GI motility disorders, including gastroesophageal reflux, functional dyspepsia, gastroparesis, intestinal motility disorders and constipation. Various methods of gastrointestinal electrical stimulation are introduced. A few methods of nerve stimulation have also been described, including spinal cord stimulation and sacral nerve stimulation. Potentials of electrical therapies for obesity are also discussed. PubMed was searched using keywords and their combinations: electrical stimulation, spinal cord stimulation, sacral nerve stimulation, gastrointestinal motility and functional gastrointestinal diseases. Expert commentary: Electrical stimulation is an area of great interest and has potential for treating GI motility disorders. However, further development in technologies (devices suitable for GI stimulation) and extensive clinical research are needed to advance the field and bring electrical therapies to bedside.

Effectiveness of percutaneous tibial nerve stimulation in managing refractory constipation

AIM

Chronic constipation can be aetiopathogenically classified into slow transit constipation (STC), rectal evacuation difficulty (RED) or a combination (BOTH). Although the efficacy of percutaneous tibial nerve stimulation (PTNS) in faecal incontinence has been well proved, a current literature search identifies only one study which assessed its effect on constipation. We aimed to evaluate the effectiveness of PTNS in patients with different causes of constipation.

METHOD

Thirty-four patients [30 women, median age 50 (20-79) years] with constipation who had previously failed maximal laxative and biofeedback therapy participated in the study. All patients underwent a baseline radio-opaque marker transit study and anorectal physiology examination. All had 12 sessions of PTNS of 30 min per session. A fall in the Wexner constipation score to ≤15 or by ≥5 points was taken as the primary outcome. Secondary outcomes included the results of pre- and post- PTNS transit and anorectal physiology studies.

RESULTS

Eleven patients had STC, 14 had RED and nine had BOTH. A response was seen in four patients (1/11 STC, 2/14 RED and 1/9 BOTH). Comparing pre- and post- PTNS, there was no significant change in the mean Wexner score (P = 0.10). There was no change in colonic transit time among the whole population (P = 0.56) or among those with STC (P = 0.47). There was no improvement in balloon expulsion in the whole group (P = 0.73) or in patients with RED (P = 0.69).

CONCLUSION

PTNS is of no benefit to patients with constipation, whatever aetiopathogenic mechanism is responsible for the symptoms.

Normative values for stool frequency and form using Rome III diagnostic criteria for functional constipation in adults: systematic review with meta-analysis

When designing clinical trials focused on functional constipation therapies, understanding the normative values of populations selected using the Rome III criteria is important for estimating baseline symptom severity, and for power analysis and sample size calculations. The objective of this review was to determine normative ranges for stool frequency and form in adults with functional constipation (Rome III criteria). Eligible studies reported stool frequency or form; random effects meta-analysis was performed with subgroup analyses to explore sources of heterogeneity. A total of 25 studies (43 groups, 2292 subjects) were included. Pooled estimates were 2.7 (95% CI 2.4-3.0) for weekly stools and 2.4 (95% CI 2.1-2.6) for stool form (Bristol scale). Heterogeneity was high for both outcomes (both I²=96%, P<0.001). Subgroup analysis revealed that weekly bowel movement frequency was higher in larger than in smaller studies (3.1 vs. 2.3, P<0.001) and in studies conducted in Europe compared with those in the Americas (3.1 vs. 2.2, P=0.02). For stool form, the use of a daily diary versus subject recall was the sole explanatory variable (2.5 vs. 2.1, P<0.05). We conclude that adults with functional constipation have significant variation in stool frequency and form, explained in part by geography and study design.

Transcutaneous electric nerve stimulation in treatment of functional constipation: A systematic review

AIM: To evaluate the effect of transcutaneous electric nerve stimulation (TENS) on symptoms, psychology and quality of life in patients with functional constipation (FC).

METHODS: The reported studies about the efficacy of TENS in improving symptom of FC were retrieved up to May 2015 based on five English databases including PubMed, Embase, Cochrane Library, ScienceDirect, and Web of Science and four Chinese databases including China National Knowledge Infrastructure (CNKI), Wanfang Data, VIP Database and China Biology Medicine disc (CBM). The methodological quality was evaluated using the Jadad scale. Meta-analysis of eligible studies was performed using RevMan5.1. Data which were unable to convent or merge were described via descriptive analysis.

RESULTS: A total of 8 studies were included. Results of analysis indicated that: (1) TENS was superior to mosapride citrate or sham transcutaneous neuromodulation (TN) in improving the symptoms of constipation and showed the same effect as polyethylene glycol or electroacupuncture (except stool consistency) (P < 0.05); (2) TENS outperformed laxative or sham TN in accelerating colonic transit (MD = -4.62, 95%CI: -5.15--4.09, P < 0.00001); (3) Compared with electroacupuncture or sham TN, TENS could significantly reduce the anxiety and depression levels and improve the quality of life (SAS score: MD = 4.10, 95%CI: 3.53-4.67, MD = 2.77, 95%CI: 2.16-3.38, P < 0.00001; SDS score, MD = 4.22, 95%CI: 3.36-5.08, P < 0.00001).

CONCLUSION: TENS had a certain therapeutic effect on FC, and it could reduce the anxiety and depression levels and improve the quality of life of the patients. Compared with laxative or electroacupuncture, TENS is user-friendly and shows fewer side effects.