Behavioural and new pharmacological treatments for constipation: getting the balance right

Can a Defecation Posture Modifying Device Correct an Abnormal Balloon Expulsion Test in Chronically Constipated Patients?

Evacuation disorders are common among chronically constipated (CC) patients who fail to respond to laxatives and are typically diagnosed by anorectal manometry (ARM) and/or balloon expulsion testing (BET).^1,2 Recently, there has been emerging interest in the use of defecation posture-modifying devices (DPMDs) to improve constipation symptoms, presumably by replicating the physiologic benefits of squatting on stool evacuation, such as straightening of the anorectal angle and relaxing the pelvic floor. However, the ability of DPMDs to normalize anorectal function in adult patients with CC has not been studied.

Analysis of the impact on efficacy of lubiprostone dose reduction to manage adverse events in the treatment of chronic constipation in Japan

OBJECTIVE

To compare outcomes between two doses of lubiprostone in patients with chronic constipation (CC), to assess whether dose reduction affects efficacy.

METHODS

This open-label exploratory study involved 146 patients with CC treated initially with lubiprostone 24 mcg twice daily for a planned duration of 4 weeks. Patients who experienced adverse events (AEs) had their dose reduced to 12 mcg twice daily (for 4 weeks).

RESULTS

Lubiprostone dose was unchanged in 104 patients and reduced due to AEs in 42 patients. Significant differences in the mean number of bowel movements per week favored the dose-reduced group at Week 1 and end of follow-up. No between-group differences were observed over time for mean number of days per week with bowel movements or mean Bristol Stool Form Scale scores. Symptoms of abdominal bloating, strained defecation, and sensation of incomplete evacuation improved in both groups. Before dose reduction, nausea was reported by 64.3% and diarrhea by 45.2% of patients in the dose-reduced group; after dose reduction, no patients reported nausea and one patient reported diarrhea.

CONCLUSION

Dose reduction of lubiprostone reduced the incidence of AEs, with no compromise to efficacy, and may be a suitable approach for patients who develop AEs during treatment.

Mechanisms of Action of Current Pharmacologic Options for the Treatment of Chronic Idiopathic Constipation and Irritable Bowel Syndrome With Constipation

Multiple therapeutic agents are currently available for the treatment of chronic idiopathic constipation and irritable bowel syndrome with constipation. A better understanding of the mechanism of action of each treatment provides important insights into expected responses and is key to optimizing treatment outcomes. Some constipation treatments, such as stimulant laxatives, may increase bowel movement frequency but are ineffective at relieving, and may even exacerbate, abdominal symptoms. On the contrary, prescription treatments, such as the guanylyl cyclase-C agonists, for example, may improve bowel symptoms and reduce visceral hypersensitivity. This review summarizes the mechanisms of action of commonly used over-the-counter and prescription therapies for chronic idiopathic constipation and irritable bowel syndrome with constipation, outlining how these mechanisms contribute to the efficacy and safety of each treatment option.

Very long-term outcome after resection rectopexy for internal rectal intussusception

BACKGROUND

Both at short- and long-term follow-up we have reported major improvement of the symptom of constipation in patients treated with resection rectopexy for internal rectal intussusception (IRI). The aim was to study whether this improvement also persisted in a cohort of these patients after very long-term follow-up.

METHODS

Observational and mainly prospective study of a cohort of 13 out of 48 patients with IRI who initially had ligament-preserving resection rectopexy with suture by laparoscopic (n = 11) or open (n = 2) technique. Outcome measures were morbidity, scores for constipation and anal incontinence, patients' report and HRQL.

RESULTS

Thirteen out of the 48 initial patients (27%) reported data at very long-term follow-up. Months from preoperatively to short-, long- and very long-term follow-up were median 6, 76 and 159, respectively. Corresponding mean (95% CI) constipation scores were 11.5 (8.3-14.7), 4.2 (1.7-6.6) (p < .001), 5.3 (3.6-7.0) (p < .05) and 13.6 (8.2-19.0). Number of constipated patients were (score ≥ 10) were 8, 1, 0, 1 and 9, respectively. Scores for anal incontinence were 6.1 (2.4-11.4), 5.8 (2.0-9.5), 4.9 (0.9-9.0) and 7.9 (4.3-11.5), respectively. HRQL life was reduced for bodily pain, social functioning, mental health and general health perception. Percentage patients reporting symptomatic improvement were 100, 70 and 53, respectively.

CONCLUSIONS

Patients with IRI have a symptomatic relief for more than 6 years after resection rectopexy. The operation did not inflict permanent patient sequela. Motivated patients must be informed about very long-term deterioration of symptomatic relief.

Treatment Algorithm for Chronic Idiopathic Constipation and Constipation-Predominant Irritable Bowel Syndrome Derived from a Canadian National Survey and Needs Assessment on Choices of Therapeutic Agents

Background. Chronic idiopathic constipation (CIC) and constipation-predominant irritable bowel syndrome (IBS-C) are common functional lower gastrointestinal disorders that impair patients' quality of life. In a national survey, we aimed to evaluate (1) Canadian physician practice patterns in the utilization of therapeutic agents listed in the new ACG and AGA guidelines; (2) physicians satisfaction with these agents for their CIC and IBS-C patients; and (3) the usefulness of these new guidelines in their clinical practice. Methods. A 9-item questionnaire was sent to 350 Canadian specialists to evaluate their clinical practice for the management of CIC and IBS-C. Results. The response rate to the survey was 16% (n = 55). Almost all (96%) respondents followed a standard, stepwise approach for management while they believed that only 24% of referring physicians followed the same approach. Respondents found guanylyl cyclase C (GCC) agonist most satisfying when treating their patients. Among the 69% of respondents who were aware of published guidelines, only 50% found them helpful in prioritizing treatment choices and 69% of respondents indicated that a treatment algorithm, applicable to Canadian practice, would be valuable. Conclusion. Based on this needs assessment, a treatment algorithm was developed to provide clinical guidance in the management of IBS-C and CIC in Canada.

Colectomy for constipation: time trends and impact based on the US Nationwide Inpatient Sample, 1998-2011

BACKGROUND

Current guidelines include subtotal colectomy as treatment for refractory slow transit constipation.

AIM

To use the US Nationwide Inpatient Sample (NIS) (1998-2011) and longitudinal data from the State Inpatient Database (2005-2011), comparable to NIS, to examine colectomy rates, in-hospital morbidity and emergency department (ED) visits or readmissions among patients treated for constipation.

METHODS

Colectomies for any reason were identified based on the primary procedural code (ICD-9-CM 45.8x). Index hospitalisations were defined by the primary diagnosis of constipation (ICD-9-CM 564.x) associated with the primary procedural code for colectomy (ICD-9-CM45.8x) after exclusion of other diseases associated with colectomy. Demographic variables, comorbidities, complications and adverse events during the hospitalisation were captured, and ED visits and admissions were recorded for periods before and after colectomy.

RESULTS

Nationally, colectomies for constipation rose from 104 procedures in 1998 (1.2% of annual colectomies) to 311 in 2011 (2.4% of annual colectomies). While there were no perioperative deaths, perioperative complications occurred in 42.7% of patients during the index hospitalisation. Longitudinal data were analysed for 181 patients, with similar perioperative complications and a readmission rate of 28.9% within the first 30 days after the index hospitalisation. Resource utilisation was tracked for a median time of 630 (0-2386) before and 463 (0-2204) days after colectomy with unchanged ED visits (median: 2 vs. 2, P = 0.21), but increased hospitalisations (median: 1 vs. 2, P = 0.003).

CONCLUSIONS

Colectomy rates for constipation are rising, are associated with significant morbidity and do not decrease resource utilisation, raising questions about the true benefit of surgery for slow transit constipation.

Acupuncture for functional constipation: protocol of an individual patient data meta-analysis

INTRODUCTION

Functional constipation (FC) is a common gastrointestinal disease. Systematic reviews indicate that acupuncture may be effective for patients with FC. However, this conclusion is not convincing due to the quality, sample size and methodological heterogeneity of the studies included by these systematic reviews. Therefore, it is necessary for us to conduct a meta-analysis of individual patient data (IPD) from high-quality clinical trials to determine whether acupuncture is effective for patients with FC.

METHODS AND ANALYSIS

Randomised controlled trials (RCTs) of acupuncture for adult patients with FC will be searched in several databases from inception to April 2015. The corresponding authors of eligible studies will be contacted and invited to contribute raw data. The primary outcome is the change in spontaneous defaecation per week from baseline. The secondary outcomes include the proportion of responders, changes in stool quality, mean transit time, proportion of patients using laxatives and adverse events. We will check all of the data and perform reanalysis according to the statistical methodology reported in previous publications. Then we will harmonise the raw data and use a two-step method to conduct the IPD meta-analysis. First, we will calculate the effect size of acupuncture of each trial by analysis of covariance, with the principal end point as the dependent variable and the baseline scores as the covariates. Second, the effect size of acupuncture in each original study will be combined in the meta-analysis.

DISSEMINATION

On the basis of the IPD meta-analysis of high-quality RCTs, this review will answer the question of whether acupuncture is effective for FC. The findings of the review will be disseminated through peer-review publications and conference presentations.

TRIAL REGISTRATION NUMBER

PROSPERO 2014 CRD42014009901.

The effect of biofeedback therapy on dyssynergic constipation in patients with or without Irritable Bowel Syndrome

BACKGROUND

The Rome II and III diagnostic criteria for dyssynergic defecation recommended the exclusion of irritable bowel syndrome (IBS). This study determined the effect of biofeedback therapy on dyssynergic constipation in patients with or without IBS.

MATERIALS AND METHODS

This study was a nonrandomized, single blinded, semi experimental study. Dyssynergic defecation patients with and without IBS were asked to undergo biofeedback therapy 8 sessions. The defecation dynamics and balloon expulsion time were evaluated before, at the end and 1 month after the biofeedback therapy. IBS symptoms were graded using a 4-point Likert scale. Mann-Whitney U-test, Wilcoxon test and Friedman test were applied to analyze data using SPSS software package (SPSS Inc., Chicago, IL, USA).

RESULTS

After the biofeedback therapy, the IBS symptoms have been decreased significantly (the median of 2 before and 1 after therapy, P < 0.01). The biofeedback therapy significantly decreased the anismus index in IBS group by the mean of 0.75 ± 0.31, 0.28 ± 0.07 and 0.28 ± 0.06 in three phases, respectively. Similar results were found in non-IBS patients (the mean of 0.74 ± 0.32, 0.28 ± 0.08, 0.27 ± 0.08 in three phases, respectively). The symptoms of constipation (sensation of incomplete evacuation, difficult and painful defecation), defecation facilitative manual maneuver frequency, pelvic floor muscles resting amplitude and strain amplitude decreased and squeezing amplitude improved significantly after biofeedback therapy in both groups with and without IBS (P < 0.001). There were not significant differences between patients with and without IBS (P > 0.05) with respect to outcome. No complication was observed in treatment groups.

CONCLUSION

Dyssynergic constipation patients with and without IBS will likely benefit from biofeedback therapy.

Comparative pharmacokinetics of rhein in normal and loperamide-induced constipated rats and microarray analysis of drug-metabolizing genes

ETHNOPHARMACOLOGICAL RELEVANCE

Rhein is a pharmacological active component found in Rheum palmatum L. that is the major herb of the San-Huang-Xie-Xin-Tang (SHXXT), a medicinal herbal product used as a remedy for constipation. Here we have investigated the comparative pharmacokinetics of rhein in normal and constipated rats. Microarray analysis was used to explore whether drug-metabolizing genes will be altered after SHXXT treatment.

MATERIALS AND METHODS

The comparative pharmacokinetics of rhein in normal and loperamide-induced constipated rats was studied by liquid chromatography with electrospray ionization tandem mass spectrometry (LC-MS/MS). Gene expression profiling in drug-metabolizing genes after SHXXT treatment was investigated by microarray analysis and real-time polymerase chain reaction (RT-PCR).

RESULTS

A validated LC-MS/MS method was applied to investigate the comparative pharmacokinetics of rhein in normal and loperamide-induced constipated rats. The pharmacokinetic results demonstrate that the loperamide-induced constipation reduced the absorption of rhein. Cmax significantly reduced by 2.5-fold, the AUC decreased by 27.8%; however, the elimination half-life (t1/2) was prolonged by 1.6-fold. Tmax and mean residence time (MRT) were significantly prolonged by 2.8-fold, and 1.7-fold, respectively. The volume of distribution (Vss) increased by 2.2-fold. The data of microarray analysis on gene expression indicate that five drug-metabolizing genes, including Cyp7a1, Cyp2c6, Ces2e, Atp1b1, and Slc7a2 were significantly altered by the SHXXT (0.5 g/kg) treatment.

CONCLUSION

The loperamide-induced constipation reduced the absorption of rhein. Since among the 25,338 genes analyzed, there were five genes significantly altered by SHXXT treatment. Thus, information on minor drug-metabolizing genes altered by SHXXT treatment indicates that SHXXT is relatively safe for clinical application.

Constipation severity is associated with productivity losses and healthcare utilization in patients with chronic constipation

OBJECTIVE

We sought to evaluate the association between constipation severity, productivity losses and healthcare utilization in a national sample of Italian patients with chronic non-organic constipation (CC).

METHODS

We enrolled 878 outpatients with CC. Clinical and demographic data were collected by physicians during clinical examinations. Patients completed a self-administered questionnaire (Patient Assessment of Constipation-Symptoms, PAC-SYM; Work Productivity and Activity Impairment; healthcare utilization, and Symptoms Checklist 90 Revised - Somatization Scale, SCL-90 R).

RESULTS

Mean PAC-SYM score was 1.62 ± 0.69. Mean weekly sick time due to constipation was 2.7 ± 8.6 h and productivity losses due to presenteeism was 19.7% ± 22.3%. Adjusted productivity losses in patients with severe CC (PAC-SYM score 2.3-4.0) compared to patients with mild symptoms (PAC-SYM score 0.0-1.0) was Italian Purchase Power Parity US$ 6160. Constipation severity (PAC-SYM quintiles) was associated with higher healthcare utilization (RRPAC-SYM 4/01.84; p-value for linear trend <0.01). After adjustment for somatization scores, the association of constipation severity with productivity losses and healthcare utilization rates was attenuated yet statistically significant.

CONCLUSIONS

We observed a graded increase in productivity losses and healthcare utilization with increasing constipation severity. Further studies should evaluate whether significant savings might be achieved with regimens aimed at reducing the constipation severity.

A concomitant treatment by CO2-releasing suppositories improves the results of anorectal biofeedback training in patients with dyschezia: results of a randomized, double-blind, placebo-controlled trial

BACKGROUND

Dyschezia is a defecatory disorder that places a heavy burden on a patient's quality of life. Biofeedback is the recommended treatment in most cases.

OBJECTIVE

The objective of our study was to test whether a CO2-releasing suppository for patients with dyschezia could be effective in improving biofeedback training results.

DESIGN

A randomized, double-blind, multicenter, placebo-controlled study was conducted in patients (18-75 years of age) with dyschezia defined according to the modified Rome III criteria. Patients were randomly assigned to either a CO2-releasing suppository or placebo suppository once per day for 21 days.

SETTINGS

This was a multicenter trial.

PATIENTS

A total of 122 patients were randomly assigned (62 intervention group and 60 placebo group).

MAIN OUTCOME MEASURES

The primary end point was the change from day 0 to day 21 in intensity of symptoms on the basis of a self-assessed dyschezia using a visual analog scale (range, 0-100). Analyses were performed using intention-to-treat principles.

RESULTS

A greater reduction from baseline to day 21 in symptom visual analog scale score was observed in the intervention group (-41.3 mm) than in the control group (-22.3 mm). Some secondary efficacy parameters improved more in the intervention group, including the percentage of patients who improved ≥50%, symptom intensity over 21 days, stool stains on underwear or pads, and need to practice manual maneuvers to facilitate defecation at day 21. At day 21, rectal sensitivity in the intervention group (31.4 mL) was lower than in the control group (39.1 mL).

LIMITATIONS

There was a lower number of patients recruited than planned by the protocol. The sponsor stopped the trial before the inclusion of 306 participants, with no intermediate analysis. In addition, the main analysis conducted on the full analysis set population could have led to a statistical bias.

CONCLUSIONS

The results of this multicenter trial demonstrate the added benefits of a CO2-releasing suppository in patients with dyschezia who were treated by anorectal biofeedback training.

Determination of bioactive components in Chinese herbal formulae and pharmacokinetics of rhein in rats by UPLC-MS/MS

Rhein (4,5-dihydroxy-9,10-dioxoanthracene-2-carboxylic acid, cassic acid) is a pharmacological active component found in Rheum palmatum L. the major herb of San-Huang-Xie-Xin-Tang (SHXXT), a medicinal herbal product used as a remedy for constipation. Here we have determined multiple bioactive components in SHXXT and investigated the comparative pharmacokinetics of rhein in rats. A sensitive and specific method combining liquid chromatography with electrospray ionization tandem mass spectrometry has been developed and validated to simultaneously quantify six active compounds in the pharmaceutical herbal product SHXXT to further study their pharmacokinetics in rats. Multiple reaction monitoring (MRM) was employed for quantification with switching electrospray ion source polarity between positive and negative modes in a single run. There were no significant matrix effects in the quantitative analysis and the mean recovery for rhein in rat plasma was 91.6%±3.4%. The pharmacokinetic data of rhein demonstrate that the herbal formulae or the single herbal extract provide significantly higher absorption rate than the pure compound. This phenomenon suggests that the other herbal ingredients of SHXXT and rhubarb extract significantly enhance the absorption of rhein in rats. In conclusion, the herbal formulae (SHXXT) are more efficient than the single herb (rhubarb) or the pure compound (rhein) in rhein absorption.

Irritable Bowel Syndrome: Peripheral Mechanisms and Therapeutic Implications

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder, affecting about 10 to 20% of the population in developed countries. The mechanisms underlying the symptoms of this condition are poorly understood. Considered initially as the consequence of abnormal gut motility, visceral hypersensitivity, psychosocial factors and brain-gut axis dysfunction, IBS is now acknowledged as a multifactorial disorder. Specific peripheral mechanisms are involved, including mucosal immune activation, increased intestinal permeability, entero-endocrine cell products, an excess of bile acids, gut dysbiosis. A better understanding of these mechanisms could help develop new and specific therapeutic pathways in patients suffering from IBS.

Chronic constipation: a critical review

Chronic constipation is a very common symptom that is rarely associated with life-threatening diseases, but has a substantial impact on patient quality of life and consumption of healthcare resources. Despite the large number of affected patients and the social relevance of the condition, no cost-effectiveness analysis has been made of any diagnostic or therapeutic algorithm, and there are few data comparing different diagnostic and therapeutic approaches in the long term. In this scenario, increasing emphasis has been placed on demonstrating that a number of older and new therapeutic options are effective in treating chronic constipation in well-performed randomised controlled trials, but there is still debate as to when these therapeutic options should be included in diagnostic and therapeutic algorithms. The aim of this review is to perform a critical evaluation of the current diagnostic and therapeutic options available for adult patients with chronic constipation in order to identify a rational patient approach; furthermore we attempt to clarify some of the more controversial points to aid clinicians in managing this symptom in a more efficacious and cost-effective manner.

A randomised controlled study of the effect of cholinesterase inhibition on colon function in patients with diabetes mellitus and constipation

OBJECTIVES

Chronic constipation in diabetes mellitus is associated with colonic motor dysfunction and is managed with laxatives. Cholinesterase inhibitors increase colonic motility. This study evaluated the effects of a cholinesterase inhibitor on gastrointestinal and colonic transit and bowel function in diabetic patients with constipation.

DESIGN

After a 9-day baseline period, 30 patients (mean ± SEM age 50 ± 2 years) with diabetes mellitus (18 type 1, 12 type 2) and chronic constipation without defaecatory disorder were randomised to oral placebo or pyridostigmine, starting with 60 mg three times a day, increasing by 60 mg every third day up to the maximum tolerated dose or 120 mg three times a day; this dose was maintained for 7 days. Gastrointestinal and colonic transit (assessed by scintigraphy) and bowel function were evaluated at baseline and the final 3 and 7 days of treatment, respectively. Treatment effects were compared using analysis of covariance, with gender, body mass index and baseline colonic transit as covariates.

RESULTS

19 patients (63%) had moderate or severe autonomic dysfunction; 16 (53%) had diabetic retinopathy. 14 of 16 patients randomised to pyridostigmine tolerated 360 mg daily; two patients took 180 mg daily. Compared with placebo (mean ± SEM 1.98 ± 0.17 (baseline), 1.84 ± 0.16 (treatment)), pyridostigmine accelerated (1.96 ± 0.18 (baseline), 2.45 ± 0.2 units (treatment), p<0.01) overall colonic transit at 24 h, but not gastric emptying or small-intestinal transit. Treatment effects on stool frequency, consistency and ease of passage were significant (p ≤ 0.04). Cholinergic side effects were somewhat more common with pyridostigmine (p=0.14) than with placebo.

CONCLUSIONS

Cholinesterase inhibition with oral pyridostigmine accelerates colonic transit and improves bowel function in diabetic patients with chronic constipation.

Long-term outcome after resection rectopexy for internal rectal intussusception

Background and Aims. The optimal treatment of patients with internal rectal intussusception (IRI) is unresolved. The aim was to study the short- and long-term outcome of resection rectopexy in these patients. Methods. An observational and mainly prospective study of 48 patients (44 women) with IRI who had ligament-preserving suture rectopexy by laparoscopic (n = 25) or open (n = 23) technique. Outcome measures were morbidity, scores for constipation and anal incontinence, patients' report, and health-related quality of life (HRQoL). Results. From preoperatively to a median of 6 months and 76 months postoperatively, constipation scores were reduced from a mean of (95% CI) 13.20 (11.41 to 15.00) to 6.91 (5.29 to 8.54) and 6.35 (4.94 to 7.76) (P < 0.0001). The number of constipated patients was reduced from 35 to eleven and eight, respectively, and none became constipated. Nine of ten symptoms of constipation improved. Corresponding scores for anal incontinence were 4.7 (2.4–7.0), 4.0 (2.4–5.7), and 4.1 (2.3–5.8), respectively. HRQoL at long-term followup compared to the general Norwegian population was reduced in four out of eight dimensions concerning physical factors. The patient-reported outcome at short- and long-term followup was improved by 85.4% and 75.0%, respectively. Conclusions. Resection rectopexy for IRI improved the outcome. HRQoL was reduced compared with the general population.

Opioid-induced bowel dysfunction: pathophysiology and management

Opioids are the most commonly prescribed medications to treat severe pain in the Western world. It has been estimated that up to 90% of American patients presenting to specialized pain centres are treated with opioids. Along with their analgesic properties, opioids have the potential to produce substantial side effects, such as nausea, cognitive impairment, addiction and urinary retention. In the gut, opioids exert their action on the enteric nervous system, where they bind to the myenteric and submucosal plexuses, causing dysmotility, decreased fluid secretion and sphincter dysfunction, which all leads to opioid-induced bowel dysfunction (OIBD). In the clinic, this is reported as nausea, vomiting, gastro-oesophageal reflux-related symptoms, constipation, etc. One of the most severe symptoms is constipation, which can be assessed using different scales for subjective assessment. Objective methods such as radiography and colonic transit time can also be used, together with manometry and evaluation of anorectal function to explore the pathophysiology. Dose-limiting adverse symptoms of OIBD can lead to insufficient pain treatment. Even though several treatment strategies are available, the side effects are still a major challenge. Traditional laxatives are normally prescribed but they are often insufficient to alleviate symptoms, especially those from the upper gastrointestinal tract. Newer prokinetics, such as prucalopride and lubiprostone, may be more effective in alleviating OIBD. Another treatment approach is co-administration of opioid antagonists, which either cannot cross the blood-brain barrier or selectively target opioid receptors in the gastrointestinal tract. However, although these new agents have proved to be more efficacious than placebo, clinical trials still need to prove their superiority to standard co-prescribed laxative regimes.

The approach to diagnosis and treatment of chronic constipation: suggestions for a general practitioner

Chronic constipation is a frequent complaint. Symptoms of obstructive defecation (straining, hard and lumpy stools, or incomplete evacuation) are more frequent and bothersome than the frequency of bowel movements. Patient assessment is clinically based on the presence or absence of red flags. Commonly used therapies (eg, bulk-forming agents, stool softeners and stimulant laxatives) have only been evaluated in small studies of short duration. Polyethylene glycol was shown to be effective and safe in several rigorous trials with durations of more than one year. New drugs (prucalopride, lubiprostone and linaclotide) were shown to be effective and safe in well-designed and rigorous studies. Trials conducted in primary care patients are lacking for all therapies. Biofeedback and behavioural therapies are effective, but should be reserved for selected patients after proper diagnostic evaluation. A practical management algorithm is proposed using a multistep approach favouring early introduction of combined therapies and long-term step-down strategy to the lowest satisfactory regimen.

Obstructed defaecation: what is the role of rehabilitation?

AIM

The study was designed to evaluate the results of rehabilitative treatment in patients suffering from obstructed defaecation.

METHOD

Between January 2008 and July 2010, 39 patients (37 women, age range 25-73 years; and two men, aged 57 and 67 years) affected by obstructed defaecation were included in the study. After a preliminary clinical evaluation, including the Obstructed Defaecation Syndrome (ODS) score, defaecography and anorectal manometry were performed. All 39 patients underwent rehabilitative treatment according to the 'multimodal rehabilitative programme' for obstructive defaecation. At the end of the programme, all 39 patients were reassessed by clinical evaluation and anorectal manometry. Postrehabilition ODS scores were used to categorize patients arbitrarily into three classes, as follows: class I, good (score ≤ 4); class II, fair (score > 4 to ≤ 8); and class III, poor (score > 8).

RESULTS

After rehabilitation, there was significant improvement in the overall mean ODS score (P < 0.001). Thirty (76.9%) patients were included as class I (good results), of whom eight (20.5%) were symptom free. Five (12.8%) patients were considered class III. A significant postrehabilitative direct correlation was found between ODS score and pelvic surgery (ρ(s) = 0.54; P < 0.05). Significant differences were found between pre- and postrehabilitative manometric data from the straining test (P < 0.001), duration of maximal voluntary contraction (P < 0.001) and conscious rectal sensitivity threshold (P < 0.02).

CONCLUSION

After rehabilitation, some patients become symptom free and many had an improved ODS score.

Chronic constipation: current treatment options

Constipation is a common functional gastrointestinal disorder that affects patients of all ages. In 2007, a consensus group of 10 Canadian gastroenterologists developed a set of recommendations pertaining to the management of chronic constipation and constipation dominant irritable bowel syndrome. Since then, tegaserod has been withdrawn from the Canadian market. A new, highly selective serotonin receptor subtype 4 agonist, prucalopride, has been examined in several large, randomized, placebo-controlled trials demonstrating its efficacy and safety in the management of patients with chronic constipation. Additional studies evaluating the use of stimulant laxatives, polyethylene glycol and probiotics in the management of chronic constipation have also been published. The present review summarizes the previous recommendations and new evidence supporting different treatment modalities - namely, diet and lifestyle, bulking agents, stool softeners, osmotic and stimulant laxatives, prucalopride and probiotics in the management of chronic constipation. A brief summary of lubiprostone and linaclotide is also presented. The quality of evidence is presented by adopting the Grading of Recommendations, Assessment, Development and Evaluation system. Finally, a management pyramid for patients with chronic constipation is proposed based on the quality of evidence, impact of each modality on constipation and on general health, and their availabilities in Canada.

New treatment options for chronic constipation: mechanisms, efficacy and safety

The present review has several objectives, the first of which is to review the pharmacology and selectivity of serotonergic agents to contrast the older serotonergic agents (which were withdrawn because of cardiac or vascular adverse effects) with the newer generation serotonin receptor subtype 4 agonists. Second, the chloride ion secretagogues that act through the guanylate cyclase C receptor are appraised and their pharmacology is compared with the approved medication, lubiprostone. Third, the efficacy and safety of the application of bile acid modulation to treat constipation are addressed. The long-term studies of surgically induced excess bile acid delivery to the colon are reviewed to ascertain the safety of this therapeutic approach. Finally, the new drugs for opiate-induced constipation are introduced. Assuming these drugs are approved, practitioners will have a choice; however, patient responsiveness will be based on trial and error. Nevertheless, the spectrum of mechanisms and demonstrated efficacy and safety augur well for satisfactory treatment outcomes.

Metabolism and pharmacokinetics of naronapride (ATI-7505), a serotonin 5-HT(4) receptor agonist for gastrointestinal motility disorders

The absorption and disposition of the serotonin 5-HT(4) receptor agonist, naronapride (6-[(3S,4R)-4-(4-amino-5-chloro-2-methoxy-benzoylamino)-3-methoxy-piperidin-1-yl]-hexanoic acid 1-aza-bicyclo[2,2,2]oct-(R)-3-yl ester dihydrochloride; ATI-7505), were evaluated in healthy males given a single 120-mg oral dose of (14)C-labeled compound. Serial blood samples and complete urine and feces were collected up to 552 h postdose. Naronapride was extensively metabolized, undergoing rapid hydrolysis to 6-[(3S,4R)-4-(4-amino-5-chloro-2-methoxy-benzoylamino)-3-methoxy-piperidin-1-yl]-hexanoic acid (ATI-7500) with stoichiometric loss of quinuclidinol. ATI-7500 was either N-glucuronidated on the phenyl ring or its hexanoic acid side chain underwent two-carbon cleavage, probably through a β-oxidation metabolic pathway, to form 4-[(3S,4R)-4-(4-amino-5-chloro-2-methoxy-benzoylamino)-3-methoxy-piperidin-1-yl]-butanoic acid (ATI-7400). ATI-7400 underwent further side-chain oxidation to form 2-[(3S,4R)-4-(4-amino-5-chloro-2-methoxy-benzoylamino)-3-methoxy-piperidin-1-yl]-acetic acid (ATI-7100). Quinuclidinol, ATI-7500, ATI-7400, and ATI-7100 were the major metabolites, with plasma area under the curve values approximately 72-, 17-, 8-, and 2.6-fold that of naronapride. Naronapride, ATI-7500, ATI-7400, and ATI-7100 accounted for 32.32, 36.56, 16.28, and 1.58%, respectively, of the dose recovered in urine and feces. ATI-7400 was the most abundant radioactive urinary metabolite (7.77%), and ATI-7500 was the most abundant metabolite in feces (35.62%). Fecal excretion was the major route of elimination. Approximately 32% of the dose was excreted unchanged in feces. Naronapride, ATI-7500, and quinuclidinol reached peak plasma levels within 1 h postdose. Peak ATI-7400 and ATI-7100 concentrations were reached within 1.7 h, suggesting rapid ATI-7500 metabolism. Naronapride plasma terminal half-life was 5.36 h, and half-lives of the major metabolites ranged from 17.69 to 33.03 h. Naronapride plasma protein binding was 30 to 40%. The mean blood/plasma radioactivity ratio indicated minimal partitioning of (14)C into red blood cells.

Colonic dysmotility in constipation

Constipation is a common and distressing condition with major morbidity, health care burden, and impact on quality of life. Colonic motor dysfunction remains the leading hypothesis to explain symptom generation in the most severe cases of chronic constipation and physiological testing plays a role in identifying the colonic dysmotility and the subsequent patient management. Measurement of colonic motor patterns and transit has enhanced our knowledge of normal and abnormal colonic motor physiology. The scope of this review encompasses the latest findings that improve our understanding of the motility disorders associated with colonic dysfunction in both the paediatric and adult population suffering from constipation.

Differences in taste between three polyethylene glycol preparations: a randomized double-blind study

BACKGROUND AND AIM

Patients suffering from chronic constipation require long-term, regular therapy with laxatives. Literature regarding patient preference and acceptance in polyethylene glycol preparations is scarce. Therefore, this research aimed to identify preference between the three polyethylene glycol 3350, namely Molaxole(®), Movicol(®), and Laxtra Orange(®). Furthermore, taste is one of the most important factors leading to patients' adherence, particularly when the treatment lasts for a long time.

METHODS

In this randomized, cross-over double-blind study, 100 volunteers were recruited by advertisement. The volunteers were invited to taste the preparations and grade the taste using a five-point hedonic scale (extremely poor taste [1] to extremely good taste [5]). The volunteers were then asked to choose the most palatable preparation.

RESULTS

One hundred volunteers with a mean age of 35 years (range 20-61) were randomized (76 females). Molaxole(®), Movicol(®), and Laxtra Orange(®) had a mean hedonic score of 2.76 (SD: 0.82), 2.81 (SD: 0.76) and 3.12 (SD: 0.82) respectively. The hedonic taste score for Laxtra Orange(®) was significantly better than Molaxole(®) (P = 0.001) and Movicol(®) (P = 0.001). No difference was found between Molaxole(®) and Movicol(®) (P = 0.61). Molaxole(®) was the most preferred preparation for 19 volunteers (19%), Movicol(®) for 24 volunteers (25%) and Laxtra Orange(®) for 55 volunteers (56%). Two volunteers had no preference. The order in which volunteers tested the preparations had no influence on the taste results. No significant differences in age or gender were observed.

CONCLUSION

Laxtra Orange(®) was most palatable preparation. This may have implications for adherence in patients with chronic constipation.