Diagnosis and treatment of chronic constipation--a European perspective

New pharmacological treatment options for chronic constipation

INTRODUCTION

A number of new medications were recently demonstrated to be more effective than placebo in treating chronic constipation, including the intestinal chloride channel activator lubiprostone, the prokinetic selective 5-HT4 receptor agonist prucalopride and the guanylate cyclase-C agonist linaclotide. Recent publications have also revisited traditional laxatives like PEG. Moreover, a number of pharmacological treatments are in development and these include another guanylate cyclase-C agonist, plecanatide and an ileal bile acid transporter inhibitor, elobixibat.

AREAS COVERED

This review focuses on the pharmacology, efficacy and safety profile of prucalopride, linaclotide, plecanatide and elobixibat.

EXPERT OPINION

The possible present or future clinical application of prucalopride, linaclotide, plecanatide and elobixibat in both chronic constipation and irritable bowel syndrome with constipation is reported, and some considerations on the possible role of PEG taking into account recent literature are advanced.

In-hospital costs associated with chronic constipation in Belgium: a retrospective database study

BACKGROUND

Real-life data on the economic burden of chronic idiopathic constipation are scarce. The objectives of this study were to assess hospitalization resource use and costs associated with chronic constipation and its complications in Belgium.

METHODS

This was a single country, retrospective study using the IMS Hospital Disease Database (2008), which comprises data on 34% of acute hospital beds in Belgium and contains information on patient demographics, length of stay (LOS), billed costs, drug use, diagnoses, and procedures. Stays with a primary diagnosis of constipation, or a secondary diagnosis of constipation and a concomitant diagnosis of a constipation-related complication, were selected. Patients with diagnoses of colorectal cancer, ulcerative colitis or Crohn's disease, or who had stays involving potentially constipation-inducing procedures, were excluded as having secondary constipation. Patients receiving opioids, calcium-antagonists, antipsychotics or antidepressants were excluded as having drug-induced constipation.

KEY RESULTS

In total, 1541 eligible patients were identified. The average unadjusted cost per day in hospital for idiopathic constipation was €441 (€311 ± 1.4 in day clinic visits without overnight stays; €711 ± 14.0 in full hospitalizations with complications). The average LOS in a full hospitalization setting was 7.0 and 4.0 days in stays with and without complications, respectively. The most frequent drug and procedural treatments were osmotically acting laxatives (with complications: 42.61%; without complications: 35.69%), and transanal enema (2.32% and 2.03%), respectively.

CONCLUSIONS & INFERENCES

The burden of constipation is often underestimated; it is a condition reflected by hospital-related costs comparable to such indications as migraine, which increase when associated with complications.

Effect of prucalopride on the pharmacokinetics of oral contraceptives in healthy women

Background

Prucalopride is a selective, high-affinity, 5-hydroxytryptamine 4 (5-HT₄) receptor agonist, which is approved for the symptomatic treatment of chronic constipation in women in whom laxatives fail to provide adequate relief. Women of childbearing potential, many of whom will be using oral contraceptives, comprise a large proportion of patients seeking medical therapy for constipation.

Objective

The aim of this study was to evaluate the effect of prucalopride on the absorption and steady-state pharmacokinetics of oral contraceptives in healthy women.

Methods

Sixteen women (aged 18–45 years) were enrolled in this open-label, two-way crossover trial (ClinicalTrials.gov identifier: NCT01036893) and given two 5-day treatments with a once-daily oral contraceptive (ethinylestradiol 0.035 mg + norethisterone 1 mg), alone and in combination with prucalopride 2 mg once daily. Treatments were separated by a 7 ± 2-day washout period. On days 1 and 5, blood samples were obtained pre-dose and at regular intervals post-dose up to 24 and 48 hours, respectively, to determine ethinylestradiol and norethisterone plasma concentrations. Prucalopride plasma concentrations were determined pre-dose and 3 hours post-dose on days 1 and 5, and 24 hours post-dose on day 6. Safety was assessed.

Results

Thirteen participants completed the study. One participant was thought to be non-compliant on days 3 and/or 4, and was excluded from the day 5 analysis. On days 1 and 5, maximum plasma concentrations of both oral contraceptive constituents were attained in ~1 hour and were unaffected by prucalopride administration. On day 5, steady-state prucalopride and oral contraceptive concentrations had been achieved. Prucalopride did not affect the pharmacokinetics of the oral contraceptives: point estimates for the maximum plasma concentration and area under the plasma concentration–time curve values and their associated 90 % confidence intervals were contained within predefined equivalence limits (80–125 %). Prucalopride was well tolerated, with a safety profile consistent with those observed in previous studies.

Conclusion

Co-administration of prucalopride with an oral contraceptive did not result in any clinically meaningful pharmacokinetic interactions and was well tolerated.

Effects of novel TRPA1 receptor agonist ASP7663 in models of drug-induced constipation and visceral pain

Constipation is a major gastrointestinal motility disorder with clinical need for effective drugs. We previously reported that transient receptor potential ankyrin 1 (TRPA1) is highly expressed in enterochromaffin (EC) cells, which are 5-hydroxytryptamine (5-HT)-releasing cells, and might therefore be a novel target for constipation. Here, we examined the effects of ASP7663, a novel and selective TRPA1 agonist, in constipation models as well as an abdominal pain model. ASP7663 activated human, rat, and mouse TRPA1 and released 5-HT from QGP-1 cells, and oral but not intravenous administration of ASP7663 significantly improved the loperamide-induced delay in colonic transit in mice. While pretreatment with the TRPA1 antagonist HC-030031 and vagotomy both inhibited the ameliorating effect of oral ASP7663 on the colonic transit, both orally and intravenously administered ASP7663 significantly inhibited colorectal distension (CRD)-induced abdominal pain response in rats. Taken together, these results demonstrate that ASP7663 exerts both anti-constipation and anti-abdominal pain actions, the former is likely triggered from the mucosal side of the gut wall via activation of vagus nerves while the latter is assumed to be provoked through systemic blood flow. We conclude that ASP7663 can be an effective anti-constipation drug with abdominal analgesic effect.

Chronic constipation and treatment options (Review)

Chronic constipation (CC) is a highly prevalent heterogeneous disorder. Although CC is not known to be associated with the development of serious disease or with excess mortality, it considerably reduces the patients quality of life. In addition, it represents an economic burden to patients and society. The majority of patients with CC successfully manage the disorder by dietary management and the use of laxatives. Patients with functional CC (slow‑transit and non‑slow transit constipation) do not respond to laxatives and are a small fraction of the total population complaining of constipation. Regardless of the low number of these patients, the intractability of their symptoms causes psychological and social stress and greatly impairs their quality of life. Furthermore, these patients consume a disproportionate quantity of medical resources. It appears that these patients have a disturbance in the serotonin transmission system, which results in a cascade of alterations in a number of gut neuroendocrine hormones/transmitters. The effect of prucalopride, a serotonin receptor agonist, in this category of patients appears to be not only a pharmacological prokinetic action, but also a correction of a pre‑existing disturbance. Linaclotide, a member of the guanylin peptide family, binds to the ligand‑binding region of guanylate cyclase‑C on the luminal surface of gastrointestinal epithelia resulting in increased fluid secretion. This drug has also been found to be effective for the treatment of functional CC. In addition, biofeedback and sacral nerve stimulation are effective in the treatment of CC caused by pelvic floor disorders.

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.

Cellular and molecular basis of chronic constipation: Taking the functional/idiopathic label out

In recent years, the improvement of technology and the increase in knowledge have shifted several strongly held paradigms. This is particularly true in gastroenterology, and specifically in the field of the so-called “functional” or “idiopathic” disease, where conditions thought for decades to be based mainly on alterations of visceral perception or aberrant psychosomatic mechanisms have, in fact, be reconducted to an organic basis (or, at the very least, have shown one or more demonstrable abnormalities). This is particularly true, for instance, for irritable bowel syndrome, the prototype entity of “functional” gastrointestinal disorders, where low-grade inflammation of both mucosa and myenteric plexus has been repeatedly demonstrated. Thus, researchers have also investigated other functional/idiopathic gastrointestinal disorders, and found that some organic ground is present, such as abnormal neurotransmission and myenteric plexitis in esophageal achalasia and mucosal immune activation and mild eosinophilia in functional dyspepsia. Here we show evidence, based on our own and other authors’ work, that chronic constipation has several abnormalities reconductable to alterations in the enteric nervous system, abnormalities mainly characterized by a constant decrease of enteric glial cells and interstitial cells of Cajal (and, sometimes, of enteric neurons). Thus, we feel that (at least some forms of) chronic constipation should no more be considered as a functional/idiopathic gastrointestinal disorder, but instead as a true enteric neuropathic abnormality.

Interpretation of overall colonic transit in defecation disorders in males and females

BACKGROUND

There is little information regarding gender-specific measurements of colonic transit and anorectal function in patients with defecation disorders (DD). To compare overall colonic transit by gender in DD.

METHODS

In 407 patients with constipation due to DD diagnosed by a single gastroenterologist (1994-2012), DD was characterized by anorectal manometry, balloon expulsion test, and colonic transit by scintigraphy. The primary endpoint was overall colonic transit (geometric center, GC) at 24 h (GC24). Effects of gender in DD on colonic transit, and comparison with transit in 208 healthy controls were assessed by Mann-Whitney rank sum test. Secondary endpoints were maximum anal resting (ARP) and squeeze (ASP) pressures. We also tested association of the physiological endpoints among DD females by pregnancy history and among DD patients by colectomy history.

KEY RESULTS

The DD patients were 67 males (M) and 340 females (F). Significant differences by gender in DD patients were observed in GC24 (median: M: 2.2; F: 1.8; P = 0.01), ARP (median: M: 87.8 mmHg; F: 82.4 mmHg; P = 0.04), and ASP (median: M: 182.4 mmHg; F: 128.7 mmHg; P < 0.001). GC24 was slower in DD compared with same-gender healthy controls. GC24 did not differ among DD females by pregnancy history. Anorectal functions and upper GI transit did not differ among DD patients by colectomy history.

CONCLUSIONS & INFERENCES

Patients with DD have slower colonic transit compared with gender-matched controls. Among DD patients, males have higher ARP and ASP, and females have slower colonic transit. Although the clinical significance of these differences may be unclear, findings suggest that interpretation of these tests in suspected DD should be based on same-gender control data.

Systemic sclerosis and the gut

Gastrointestinal involvement (GI) is increasingly recognized as a major cause of both morbidity and mortality in systemic sclerosis (SSc). GI complications are common, second only to skin involvement, and affect up to 90% of patients. Although treatment modalities have changed little for upper gut symptoms such as GI reflux, there are emerging treatment modalities for the common lower gut symptoms (constipation and fecal incontinence), which will be reviewed. The important link between reflux and interstitial lung disease in SSc is also addressed. The aim of this review is to help the clinician understand and manage GI symptoms in SSc.

Randomised clinical trial: macrogol/PEG 3350+electrolytes versus prucalopride in the treatment of chronic constipation -- a comparison in a controlled environment

BACKGROUND

Constipation is a common condition for which PEG 3350 is an established treatment and prucalopride has recently been approved for this indication.

AIM

To compare the efficacy, safety and impact on quality of life (QoL) of PEG 3350 plus electrolytes (PEG 3350+E) vs. prucalopride in females with chronic constipation (CC) in whom laxatives have previously failed to provide adequate relief.

METHODS

In this single-centre, randomised, double-blind, double-dummy study, patients with CC [<3 spontaneous complete bowel movements (SCBM)/week] remained in a controlled environment and received either a 26 g split dose of PEG 3350+E (N = 120) or 1-2 mg prucalopride (N = 120) daily for 28 days following a 14-day run-in period. The primary endpoint was the proportion of patients having ≥3 SCBMs during the last treatment week.

RESULTS

Non-inferiority of PEG 3350+E to prucalopride was demonstrated in the per-protocol population [difference, 10.1% (66.67% vs. 56.52%), 97.5% lower confidence interval (CI) -2.7%, above the preset margin of -20%] and approached superiority in the modified intent-to-treat population (difference, 9.8%, 97.5% lower CI, -3.1%). Statistically significant differences in favour of PEG 3350+E were observed for most secondary variables (bowel movements, stool weight, consistency, time to next SCBM, patient perception of straining and completeness of defecation). Colonic transit time was dramatically reduced in both arms. Both treatments were well tolerated.

CONCLUSION

PEG 3350+E was at least as effective as and generally better tolerated than prucalopride as a treatment for chronic constipation in this study population (NCT01251822; http://www.clinicaltrials.gov).

Primary Care Management of Chronic Constipation in Asia: The ANMA Chronic Constipation Tool

Chronic constipation (CC) may impact on quality of life. There is substantial patient dissatisfaction; possible reasons are failure to recognize underlying constipation, inappropriate dietary advice and inadequate treatment. The aim of these practical guidelines intended for primary care physicians, and which are based on Asian perspectives, is to provide an approach to CC that is relevant to the existing health-care infrastructure. Physicians should not rely on infrequent bowel movements to diagnose CC as many patients have one or more bowel movement a day. More commonly, patients present with hard stool, straining, incomplete feeling, bloating and other dyspeptic symptoms. Physicians should consider CC in these situations and when patients are found to use laxative containing supplements. In the absence of alarm features physicians may start with a 2-4 week therapeutic trial of available pharmacological agents including osmotic, stimulant and enterokinetic agents. Where safe to do so, physicians should consider regular (as opposed to on demand dosing), combination treatment and continuous treatment for at least 4 weeks. If patients do not achieve satisfactory response, they should be referred to tertiary centers for physiological evaluation of colonic transit and pelvic floor function. Surgical referral is a last resort, which should be considered only after a thorough physiological and psychological evaluation.

Spatiotemporal maps reveal regional differences in the effects on gut motility for Lactobacillus reuteri and rhamnosus strains

BACKGROUND

Commensal bacteria such as probiotics that are neuroactive acutely affect the amplitudes of intestinal migrating motor complexes (MMCs). What is lacking for an improved understanding of these motility effects are region specific measurements of velocity and frequency. We have combined intraluminal pressure recordings with spatiotemporal diameter maps to analyze more completely effects of different strains of beneficial bacteria on motility.

METHODS

Intraluminal peak pressure (PPr) was measured and video recordings made of mouse ex vivo jejunum and colon segments before and after intraluminal applications of Lactobacillus rhamnosus (JB-1) or Lactobacillus reuteri (DSM 17938). Migrating motor complex frequency and velocity were calculated.

KEY RESULTS

JB-1 decreased jejunal frequencies by 56% and 34% in colon. Jejunal velocities increased 171%, but decreased 31% in colon. Jejunal PPr decreased by 55% and in colon by 21%. DSM 17938 increased jejunal frequencies 63% and in colon 75%; jejunal velocity decreased 57%, but increased in colon 146%; jejunal PPr was reduced 26% and 12% in colon. TRAM-34 decreased frequency by 71% and increased velocity 200% for jejunum, but increased frequency 46% and velocity 50% for colon; PPr was decreased 59% for jejunum and 39% for colon.

CONCLUSIONS & INFERENCES

The results show that probiotics and other beneficial bacteria have strain and region-specific actions on gut motility that can be successfully discriminated using spatiotemporal mapping of diameter changes. Effects are not necessarily the same in colon and jejunum. Further research is needed on the detailed effects of the strains on enteric neuron currents for each gut region.

[Chronic constipation in adults]

Chronic constipation is a very common condition, which is responsible for a major socioeconomic burden. Primary management must rule out secondary constipation before recognizing chronic idiopathic constipation, which is the most common diagnosis. Initial treatment frequently associates simple lifestyle modifications, whose efficacy is limited, with osmotic laxatives or bulking agents. If those measures do not relieve symptoms, a switch of laxatives or a combination must be proposed. Pharmacological treatments of constipation represent a new alternative approach in case of failure of previously mentioned measures. In case of chronic constipation reluctant to all conservative therapies, specific tests are required before considering biofeedback intervention or exceptionally a surgical option.

Colonic motility-promoting agents for treatment of chronic constipation

Chronic constipation (CC) is one of the most common functional gastroin testinal disorders. Possible etiologies for CC include alterations in gastrointestinal motility and secretion. Research efforts in CC have led to the identification of multifactorial and often overlapping etiologies including abnormalities in myenteric neurons, alterations in neurotransmitters and their receptors, and incoordination of the muscles of the pelvic floor or anorectum. In this article, we review the safety and efficacy of colonic motility-promoting agents, such as 5-HT modulators, motilin agonists, chloride-channel activators, opioid antagonists, uroguanylin and GC-2C receptor agonists, in the management of CC.

Prucalopride: evaluation of the pharmacokinetics, pharmacodynamics, efficacy and safety in the treatment of chronic constipation

INTRODUCTION

Prucalopride is the first member of a novel class of 5-HT(4) receptor agonist which has been extensively evaluated for the treatment of chronic constipation. Predominantly, prucalopride is currently used to treat patients that show an insufficient response to laxatives as an alternative form of therapy.

AREAS COVERED

The following article provides the reader with a systematic review of the literature on prucalopride. Specifically, the article reviews the currently literature on the pharmacokinetics and the pharmacodynamics of the drugs as well as reviewing literature on its efficacy. Furthermore, the authors also highlight the safety and tolerability of the drug that have been demonstrated in its clinical development.

EXPERT OPINION

Prucalopride is an important addition to the therapeutic abilities for treating chronic constipation, especially in females poorly responding to laxatives. The safety profile of the drug, to date, is favorable. There is also the possibility that prucalopride might be of benefit to other disorders of gastrointestinal motility with a number of studies currently in progress, which are evaluating alternative applications.

Levels of satisfaction with current chronic constipation treatment options in Europe - an internet survey

BACKGROUND

Data on treatment satisfaction in European men and women with chronic constipation are limited.

AIM

To assess satisfaction with current treatment among European men and women with chronic constipation.

METHODS

An internet-based survey was conducted in 2009 in 10 European countries: Austria, Germany, France, Ireland, Italy, Spain, Switzerland, the UK, Belgium and the Netherlands. Participants had self-reported chronic constipation (<3 bowel movements/week and ≥1 symptoms for ≥6 months of: pain during defecation; lumpy/hard faeces; and feeling of incomplete evacuation). Demographic data and disease history were collected. For participants using laxatives, drug name/class, satisfaction with treatment and interest in other treatments were collected.

RESULTS

Of the 1941 participants screened, 1355 had chronic constipation and met the inclusion criteria (chronic constipation population). The majority of the chronic constipation population who disclosed their sex (n = 811) were women (82%). Sixty-eight per cent of respondents (n = 855/1255) reported using laxatives, with the proportion of laxative users differing between subsets. Twenty-eight per cent (n = 225/793) were (very) satisfied with their treatment, whereas 44% (n = 345/793) were neutral and 28% (n = 223/793) (very) dissatisfied. There was no relationship between type of laxative and degree of (dis)satisfaction. Interest in other treatments was high with 83% (n = 686/827) of respondents 'absolutely' or 'probably' interested. Respondents dissatisfied with their treatment were more likely to be interested in other treatments.

CONCLUSIONS

Laxative-use is common for chronic constipation. In this large survey, 28% of participants were dissatisfied with their treatment, with the majority interested in other treatments.

Inhibition of aquaporin-3 water channel in the colon induces diarrhea

Aquaporin (AQP) 3, which is predominantly expressed in the colon, is considered to play an important role in regulating the fecal water content in the colon. In this study, the role of AQP3 in the colon was examined using HgCl(2) and CuSO(4), which are known to inhibit AQP3 function. The fecal water content was measured up to 1 h after the rectal administration of HgCl(2) or CuSO(4) to rats. The results showed that the fecal water content in the HgCl(2) administration group increased significantly to approximately 4 times that in the control group, and severe diarrhea was observed. However, no changes were observed in the mRNA expression level of the osmoregulatory genes (sodium myo-inositol transporter and taurine transporter) and the level and distribution of AQP3 protein expression, as determined 1 h after the administration of HgCl(2). Comparable results were observed in the CuSO(4) administration group. The results of this study indicated that the inhibition of AQP3 function in the colon caused diarrhea. Therefore, it has been revealed that the fecal water content in the colon is controlled by the transport of water from the luminal side to the vascular side, which is mediated by AQP3. Our findings suggest that a drug that modulates the function or expression of AQP3 in the colon may represent a new target for the development of laxatives.

Intestinal gas: has diet anything to do in the absence of a demonstrable malabsorption state?

PURPOSE OF REVIEW

To summarize the relevant publications during the last 12 months supporting that diet can influence gas-related symptoms in the absence of a malabsorption state.

RECENT FINDINGS

Gas symptoms during carbohydrate fermentation: a diet incorporating beans is well tolerated by a majority of individuals involved in a program of heart disease biomarkers. By contrast, in patients with irritable bowel syndrome, a diet avoiding fermentable carbohydrates improved gas-related abdominal symptoms. The rate of fermentation determines the production of abdominal symptoms, and many slowly fermentable fibers have a rapid fermentation profile that can generate abdominal symptoms. Modulation of visceral sensitivity: diet can influence gas symptoms by increasing the tolerability of the intestine to gas. Capsaicin decreases visceral hyperalgesia and improved bloating in patients with irritable bowel syndrome. Changes in gas-producing bacteria: different strains of Lactobacillus have antimicrobial properties against gas-forming coliforms. New clinical studies show beneficial effects of prebiotics and probiotics on abdominal bloating.

SUMMARY

Actual data suggest that diet could improve gas-related abdominal symptoms acting on several mechanisms: gas production, visceral hypersensitivity and modulation of gas-producing enteric bacteria.

Regional colon transit in patients with dys-synergic defaecation or slow transit in patients with constipation

OBJECTIVE

To differentiate dys-synergic defaecation (DD) from normal function and slow transit constipation (STC).

METHODS

The medical records of 1411 patients evaluated by a single gastroenterologist over a 16-year period at a tertiary medical centre were reviewed. DD was characterised by anorectal manometry and balloon expulsion test. There were 390 patients with DD, and 61 with STC without DD. Transit data from 211 healthy individuals served as controls. The primary endpoints were overall colonic transit (geometric centre) at 24 h and 48 h (GC24 and GC48). Regional transit was measured as ascending colon half-emptying time (AC t(1/2)) and residual content in descending rectosigmoid colon and stool (DRS).

RESULTS

Age and body mass index were similar in the STC and DD groups. DD was associated with smaller perineal descent and a greater difference in rectoanal pressure than STC. Both STC and DD were associated with lower GC24 and GC48 and slower AC t(1/2) than controls. GC48 differentiated DD from healthy controls (p<0.001) and DD from STC (p=0.007). AC t(1/2) values differentiated healthy controls from DD (p=0.006) and STC (p<0.001) and were associated with constipation (DD vs STC, p=0.007). The regional content of DRS at 48 h discriminated DD from STC (AUC=0.82) and stool content at 48 h, increasing the odds for DD over STC (OR per 5% in stool 2.4, 95% CI 1.1 to 5.5, p=0.03).

CONCLUSIONS

DD is associated with delayed overall colonic transit at 48 h and AC t(1/2) compared with healthy controls. Regional scintigraphic transit profiles differentiate DD from STC and facilitate identification of a subgroup of patients with constipation.

Treating constipation during pregnancy

QUESTION

Many of my patients experience constipation during pregnancy, even after increasing dietary fibre and fluids. Are there any safe treatments I can recommend to them?

ANSWER

Although the recommended first-line therapy for constipation includes increasing fibre, fluids, and exercise, these are sometimes ineffective. Therefore, laxatives such as bulk-forming agents, lubricant laxatives, stool softeners, osmotic laxatives, and stimulant laxatives might be considered. Although few of the various types of laxatives have been assessed for safety in pregnancy, they have minimal systemic absorption. Therefore, they are not expected to be associated with an increased risk of congenital anomalies. However, it is recommended that osmotic and stimulant laxatives be used only in the short term or occasionally to avoid dehydration or electrolyte imbalances in pregnant women.

Functional studies of the gastrointestinal tract in adult surgical clinics: when do they help?

Gut motility and visceral sensation are two important components of normal gastrointestinal (GI) tract function. Disordered gut motility and sensation can cause significant symptoms which not only pose a health burden to patients, but may also mimic structural diseases and may generate many surgical referrals from primary care. Unfortunately, diagnostic testing for disorders of function lags well behind that for structural disease. In this article we review common presentations of functional disorders in surgical clinics, and relevant testing modalities.

Prucalopride: safety, efficacy and potential applications

Chronic constipation is a very common functional gastrointestinal disorder which can be associated with significant impairments in quality of life for some people with the condition. Its management has, traditionally, been based on dietary and lifestyle changes and the use of a variety of laxative agents. The evidence base for the efficacy of the latter is, in many cases, slim. Not surprisingly, many patients remain dissatisfied with laxatives thus leading to the development of more pharmacological approaches. Among these approaches is the use of prokinetic agents; while prior molecules have been troubled by lack of selectivity and cardiac side effects, the new agent, prucalopride, appears to be highly selective for the serotonin 5-HT4 receptor and is, therefore, a potent stimulator of gut motility. In three large pivotal randomized controlled trials, prucalopride has been effective in relieving the cardinal symptoms of chronic constipation; these effects have been sustained in open-label follow up for as long as 18 months. The safety profile has been encouraging and, especially so, the absence of arrhythmogenic potential. Studies in men, in constipation-predominant irritable bowel syndrome and in other motor disorders are eagerly awaited.

Evolving concepts in chronic constipation in Europe and elsewhere: not worlds apart

Chronic constipation (CC) is widely prevalent in the Western world, with a significant negative impact on quality of life, yet new and effective pharmacological and non-pharmacological treatment options have only recently emerged. The article by Tack and colleagues in the current issue of NGM is timely with the recent introduction of the serotonin type 4 receptor agonist prucalopride in Europe and wider acceptance of anorectal biofeedback for patients with pelvic floor dyssynergia. This Editorial (i) highlights the importance of identifying patients with pelvic floor dysfunction who are candidates for pelvic floor retraining programs and (ii) discusses the potential limitations of the 5-HT4 agonist, prucalopride, as an early option in the treatment algorithm for CC.

Current and future therapies for chronic constipation

In this article, traditional and novel therapies for chronic constipation are reviewed. Traditional laxatives are effective at inducing bowel movements, but efficacy in long-term management and efficacy on constipation-associated abdominal symptoms are less well established, with the exception of polyethylene glycol, for which long-term studies confirm sustained efficacy. Recently approved drugs include the colonic secretagogue lubiprostone and the 5-HT4 agonist prucalopride. In controlled trials in chronic constipation, these drugs were shown to significantly improve constipation and its associated symptoms, with a favourable safety record. Methylnaltrexone, a subcutaneously administered peripherally acting mu opioid receptor antagonist, has recently been approved for opioid-induced constipation in terminally ill patients. New agents under evaluation include the 5-HT4 agonists velusetrag and naronapride, the guanylate cyclase-C receptor agonist linaclotide and the peripherally acting mu opioid receptor antagonist alvimopan.