Physiology of refractory chronic constipation

Rome IV Functional Defecation Disorder: Time for a Change in Symptom Criteria for Improved Clinical Relevance?

INTRODUCTION

Defecatory disorders are common affecting up to 8% of the population. Rome IV diagnostic criteria are used to define this condition and, therefore, select patients for the gold standard therapy, anorectal biofeedback. The aim of this study was to test the current Rome IV Functional Defecation Disorder (FDD) criteria in a real-world population by using the response to biofeedback as a validation tool.

METHODS

A total of 485 patients (female 437, mean age 50 ± 17.6 years) with defecatory symptoms presenting to a neurogastroenterology clinic underwent anorectal biofeedback therapy regardless of whether they met formal Rome IV FDD criteria or not. Patients were assessed extensively with the Rome questionnaire, constipation questionnaire, and visual analog scales for satisfaction, control, quality of life, and anorectal manometry.

RESULTS

Rome IV FDD was no better at predicting response to biofeedback compared with non-Rome IV FDD ( P = NS). Digitation ( P = 0.043) and increasing cumulative number of defecatory symptoms ( P = 0.038) were correlated with improvement in biofeedback (≥2-point increase in bowel satisfaction). Those with abnormal physiology only responded well to biofeedback (83% response rate), but this was not statistically different from no Rome IV physiology patients (73%). There was a trend for increasing cumulative number of abnormal physiology factors to correlate with biofeedback ( P = 0.086).

DISCUSSION

Rome IV symptom criteria need revision to include more defecatory symptoms, include all subtypes of irritable bowel syndrome, and be inclusive of those with either loose stools or more frequent stools such as those previously labeled with "pseudodiarrhea" or "hyperdefecation." Continuing to include physiology criteria in the Rome diagnosis of FDD seems valid.

Prevalence and Risk Factors of Constipation Symptoms among Patients Undergoing Colonoscopy: A Single-Center Cross-Sectional Study

INTRODUCTION

Constipation is one of the most common gastrointestinal symptoms. It may compromise quality of life and social functioning and result in increased healthcare use and costs. We aimed to evaluate the prevalence and risk factors of constipation symptoms, as well as those of refractory constipation symptoms among patients who underwent colonoscopy.

METHODS

Over 4.5 years, patients who underwent colonoscopy and completed questionnaires were analyzed. Patients' symptoms were evaluated using the Gastrointestinal Symptoms Rating Scale.

RESULTS

Among 8,621 eligible patients, the prevalence of constipation symptoms was 33.3%. Multivariate analysis revealed female sex (odds ratio [OR] 1.7, p < 0.001), older age (OR 1.3, p < 0.001), cerebral stroke with paralysis (OR 1.7, p = 0.009), chronic renal failure (OR 2.6, p < 0.001), ischemic heart disease (OR 1.3, p = 0.008), diabetes (OR 1.4, p < 0.001), chronic obstructive pulmonary disease (OR 1.5, p = 0.002), benzodiazepine use (OR 1.7, p < 0.001), antiparkinsonian medications use (OR 1.9, p = 0.030), and opioid use (OR 2.1, p = 0.002) as independent risk factors for constipation symptoms. The number of patients taking any medication for constipation was 1,134 (13.2%); however, refractory symptoms of constipation were still present in 61.4% of these patients. Diabetes (OR 1.5, p = 0.028) and irritable bowel syndrome (OR 3.1, p < 0.001) were identified as predictors for refractory constipation symptoms.

CONCLUSIONS

Constipation occurred in one-third of patients, and more than half of patients still exhibited refractory symptoms of constipation despite taking laxatives. Multiple medications and concurrent diseases seem to be associated with constipation symptoms.

Optimizing the Utility of Anorectal Manometry for Diagnosis and Therapy: A Roundtable Review and Recommendations

BACKGROUND & AIMS

Anorectal manometry (ARM) is a comprehensive diagnostic tool for evaluating patients with constipation, fecal incontinence, or anorectal pain; however, it is not widely utilized for reasons that remain unclear. The aim of this roundtable discussion was to critically examine the current clinical practices of ARM and biofeedback therapy by physicians and surgeons in both academic and community settings.

METHODS

Leaders in medical and surgical gastroenterology and physical therapy with interest in anorectal disorders were surveyed regarding practice patterns and utilization of these technologies. Subsequently, a roundtable was held to discuss survey results, explore current diagnostic and therapeutic challenges with these technologies, review the literature, and generate consensus-based recommendations.

RESULTS

ARM identifies key pathophysiological abnormalities such as dyssynergic defecation, anal sphincter weakness, or rectal sensory dysfunction, and is a critical component of biofeedback therapy, an evidence-based treatment for patients with dyssynergic defecation and fecal incontinence. Additionally, ARM has the potential to enhance health-related quality of life and reduce healthcare costs. However, it has significant barriers that include a lack of education and training of healthcare providers regarding the utility and availability of ARM and biofeedback procedures, as well as challenges with condition-specific testing protocols and interpretation. Additional barriers include understanding when to perform, where to refer, and how to use these technologies, and confusion over billing practices.

CONCLUSIONS

Overcoming these challenges with appropriate education, training, collaborative research, and evidence-based guidelines for ARM testing and biofeedback therapy could significantly enhance patient care of anorectal disorders.

Altered Gut Microbic Flora and Haemorrhoids: Could They Have a Possible Relationship?

To date, the exact pathophysiology of haemorrhoids is poorly understood. The different philosophies on haemorrhoids aetiology may lead to different approaches of treatment. A pathogenic theory involving a correlation between altered anal canal microflora, local inflammation, and muscular dyssynergia is proposed through an extensive review of the literature. Since the middle of the twentieth century, three main theories exist: (1) the varicose vein theory, (2) the vascular hyperplasia theory, and (3) the concept of a sliding anal lining. These phenomena determine changes in the connective tissue (linked to inflammation), including loss of organization, muscular hypertrophy, fragmentation of the anal subepithelial muscle and the elastin component, and vascular changes, including abnormal venous dilatation and vascular thrombosis. Recent studies have reported a possible involvement of gut microbiota in gut motility alteration. Furthermore, dysbiosis seems to represent the leading cause of bowel mucosa inflammation in any intestinal district. The alteration of the gut microbioma in the anorectal district could be responsible for haemorrhoids and other anorectal disorders. A deeper knowledge of the gut microbiota in anorectal disorders lays the basis for unveiling the roles of these various gut microbiota components in anorectal disorder pathogenesis and being conductive to instructing future therapeutics. The therapeutic strategy of antibiotics, prebiotics, probiotics, and fecal microbiota transplantation will benefit the effective application of precision microbiome manipulation in anorectal disorders.

Dyssynergic Defecation: A Comprehensive Review on Diagnosis and Management

About one-third of chronically constipated patients have an evacuation disorder, and dyssynergic defecation is a common cause of the evacuation disorder. In dyssynergic defecation, the coordination between abdominal and pelvic floor muscles during defecation is disrupted and patients cannot produce a normal bowel movement. The etiology of dyssynergic defecation is still unknown. Although a detailed history taking and a careful examination including digital rectal examination could be useful, other modalities such as anorectal manometry and balloon expulsion test are necessary for the diagnosis. Biofeedback therapy is one of the most effective and safe treatments. Here, we provide an overview of dyssynergic defecation as well as how to diagnose and manage this condition.

Diagnosis and treatment of constipation: a clinical update based on the Rome IV criteria

The aim of this study was to evaluate the published professional association guidelines regarding the current diagnosis and treatment of functional intestinal constipation in adults and to compare those guidelines with the authors’ experience to standardize actions that aid clinical reasoning and decision-making for medical professionals. A literature search was conducted in the Medline/PubMed, Scielo, EMBASE and Cochrane online databases using the following terms: chronic constipation, diagnosis, management of chronic constipation, Roma IV and surgical treatment. Conclusively, chronic intestinal constipation is a common condition in adults and occurs most frequently in the elderly and in women. Establishing a precise diagnosis of the physiopathology of functional chronic constipation is complex and requires many functional tests in refractory cases. An understanding of intestinal motility and the defecatory process is critical for the appropriate management of chronic functional intestinal constipation, with surgery reserved for cases in which pharmacologic intervention has failed. The information contained in this review article is subject to the critical evaluation of the medical specialist responsible for determining the action plan to be followed within the context of the conditions and clinical status of each individual patient.

Co‑expression network analysis identified specific miRNAs and genes in association with slow‑transit constipation

The pathogenesis of slow-transit constipation (STC) remains largely unclear, with the roles of microRNAs (miRs/miRNAs) yet to be determined. Co-expression network analysis of miRNAs in STC is crucial to elucidating potential underlying mechanisms. Weighted gene correlation network analysis was performed in the miRNA expression profile of STC (GSE57969). The key miRNA target genes were further functionally enriched by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO). A Protein-Protein Interaction (PPI) network was constructed, with a total of 12 color-clustered modules determined. Seven key miRNAs were established, including five miRNAs from the turquoise module (hsa-miR-20b, hsa-miR-128, hsa-miR-129-3p, hsa-miR-30b and hsa-miR-340), one miRNA from the blue module (hsa-miR-619) and one from the black module (hsa-miR-486-3p). A total of 2,077 key miRNA target genes were predicted. GO analysis revealed that the ‘protein modification process’ and ‘cellular protein modification process’ were the most significantly enriched processes in the ‘Biological Processes’ category, whereas the ‘nucleoplasm’ in ‘Cellular Components’ and ‘enzyme binding’ in ‘Molecular Functions’ were the most significantly enriched processes. The ‘cAMP signalling pathway’ was the top KEGG pathway. The hub genes identified from the PPI network included calmodulin (CALM)2, CALM1, histone deacetylase (HDAC)3, glycogen synthase kinase 3 β, HDAC9, heat-shock protein family A member 8, G-protein subunit γ (GNG)13, HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1, GNG10 and GNG7. This bioinformatics analysis demonstrated co-expressed miRNA networks with insightful genes and pathways associated with STC.

Mechanisms, Evaluation, and Management of Chronic Constipation

With a worldwide prevalence of 15%, chronic constipation is one of the most frequent gastrointestinal diagnoses made in ambulatory medicine clinics, and is a common source cause for referrals to gastroenterologists and colorectal surgeons in the United States. Symptoms vary among patients; straining, incomplete evacuation, and a sense of anorectal blockage are just as important as decreased stool frequency. Chronic constipation is either a primary disorder (such as normal transit, slow transit, or defecatory disorders) or a secondary one (due to medications or, in rare cases, anatomic alterations). Colonic sensorimotor disturbances and pelvic floor dysfunction (such as defecatory disorders) are the most widely recognized pathogenic mechanisms. Guided by efficacy and cost, management of constipation should begin with dietary fiber supplementation and stimulant and/or osmotic laxatives, as appropriate, followed, if necessary, by intestinal secretagogues and/or prokinetic agents. Peripherally acting μ-opiate antagonists are another option for opioid-induced constipation. Anorectal tests to evaluate for defecatory disorders should be performed in patients who do not respond to over-the-counter agents. Colonic transit, followed if necessary with assessment of colonic motility with manometry and/or a barostat, can identify colonic dysmotility. Defecatory disorders often respond to biofeedback therapy. For specific patients, slow-transit constipation may necessitate a colectomy. No studies have compared inexpensive laxatives with newer drugs with different mechanisms. We review the mechanisms, evaluation, and management of chronic constipation. We discuss the importance of meticulous analyses of patient history and physical examination, advantages and disadvantages of diagnostic testing, guidance for individualized treatment, and management of medically refractory patients.

Chronic Constipation

Constipation is a common symptom that may be primary (idiopathic or functional) or associated with a number of disorders or medications. Although most constipation is self-managed by patients, 22% seek health care, mostly to primary care physicians (>50%) and gastroenterologists (14%), resulting in large expenditures for diagnostic testing and treatments. There is strong evidence that stimulant and osmotic laxatives, intestinal secretagogues, and peripherally restricted μ-opiate antagonists are effective and safe; the lattermost drugs are a major advance for managing opioid-induced constipation. Constipation that is refractory to available laxatives should be evaluated for defecatory disorders and slow-transit constipation using studies of anorectal function and colonic transit. Defecatory disorders are often responsive to biofeedback therapies, whereas slow-transit constipation may require surgical intervention in selected patients. Both efficacy and cost should guide the choice of treatment for functional constipation and opiate-induced constipation. Currently, no studies have compared inexpensive laxatives with newer drugs that work by other mechanisms.

A Randomized Double-blind Placebo-controlled Trial on the Effect of Magnesium Oxide in Patients With Chronic Constipation

Background/Aims

Magnesium oxide (MgO) has been frequently used as a treatment for chronic constipation (CC) since the 1980s in Japan. The aim of this study is to evaluate its therapeutic effects of MgO in Japanese CC patients.

Methods

We conducted a randomized, double-blind placebo-controlled study. Thirty-four female patients with mild to moderate constipation were randomly assigned to either placebo (n = 17) or MgO group (n = 17) 0.5 g × 3/day for 28 days. Primary endpoint was overall improvement over the 4-week study period. Secondary endpoints were changes from baseline in spontaneous bowel movement (SBM), response rates of complete spontaneous bowel movement (CSBM), stool form, colonic transit time (CTT), abdominal symptom, and quality of life.

Results

One patient failed to complete the medication regimen and was omitted from analysis: data from 16 placebo and 17 MgO patients were analyzed. The primary endpoint was met by 25.0% of placebo vs 70.6% of MgO group (P = 0.015). MgO significantly improved SBM changes compared to placebo (P = 0.002). However, MgO did not significantly improved response rates of CSBM compared to placebo (P = 0.76). In addition, MgO significantly improved Bristol stool form scale changes (P < 0.001) and significantly improved CTT compared to the placebo group (P < 0.001). MgO significantly improved the Japanese version of the patient assessment of constipation quality of life (P = 0.003).

Conclusion

Our placebo-controlled study demonstrated that MgO was effective treatment for improving defecation status and shortened CTT in Japanese CC patients with mild to moderate symptoms.

Home Biofeedback for the Treatment of Dyssynergic Defecation: Does It Improve Quality of Life and Is It Cost-Effective?

OBJECTIVES

Biofeedback therapy, whether administered at home or in office settings, is effective for dyssynergic defecation (DD). Whether home biofeedback improves quality of life (QOL) and is cost-effective when compared with office biofeedback is unknown.

METHODS

QOL was assessed in 8 domains (SF-36) at baseline and after treatment (3 months), alongside economic evaluation during a randomized controlled trial (RCT) comparing home and office biofeedback in patients with DD (Rome III). Costs related to both biofeedback programs were estimated from the hospital financial records, study questionnaires, and electronic medical records. A conversion algorithm (Brazier) was used to calculate the patient's quality-adjusted life years (QALYs) from SF-36 responses. Cost-effectiveness was expressed as incremental costs per QALY between the treatment arms.

RESULTS

One hundred patients (96 female patients, 50 in each treatment arm) with DD participated. Six of the 8 QOL domains improved (P < 0.05) in office biofeedback, whereas 4 of the 8 domains improved (P < 0.05) in home biofeedback; home biofeedback was noninferior to office biofeedback. The median cost per patient was significantly lower (P < 0.01) for home biofeedback ($1,112.39; interquartile range (IQR), $826-$1,430) than for office biofeedback ($1,943; IQR, $1,622-$2,369), resulting in a cost difference of $830.11 The median QALY gained during the trial was 0.03 for office biofeedback and 0.07 for home biofeedback (P = NS). The incremental cost-effectiveness ratio was $20,752.75 in favor of home biofeedback.

DISCUSSION

Biofeedback therapy significantly improves QOL in patients with DD regardless of home or office setting. Home biofeedback is a cost-effective treatment option for DD compared with office biofeedback, and it offers the potential of treating many more patients in the community.

Home-based versus office-based biofeedback therapy for constipation with dyssynergic defecation: a randomised controlled trial

BACKGROUND

Office-based biofeedback therapy is effective for constipation with dyssynergic defecation, but must be performed by skilled staff, is only available in selected centres, and requires multiple visits. The efficacy of home-based biofeedback therapy is unknown. We compared clinical and subjective outcomes with home-based and office-based approaches.

METHODS

In this randomised controlled trial, eligible patients were adult outpatients (age 18-80 years) who met the Rome III criteria for functional constipation and who had been referred to a tertiary-care centre after non-response to routine management, and who had dyssynergic defecation. Patients were randomly assigned according to a schedule generated in advance by the study biostatistician, in permuted blocks of four, to receive office-based or home-based biofeedback therapy. Office-based biofeedback comprised therapist-guided pelvic floor training for six sessions over 3 months (visits every 2 weeks). Home-based biofeedback comprised 20 min self-training sessions twice per day, in which a self-inserted probe was used to provide visual feedback via a handheld monitoring device of anal sphincter pressure and push effort. Patients recorded in diaries the time of each defecation attempt, stool consistency, straining effort, feeling of incomplete evacuation, need for digital assistance with stooling, and satisfaction with bowel function, from 1 week before enrolment to the end of follow-up. Treatment responders were defined post hoc as those with normalisation of dyssynergic defecation and an increase in the number of complete spontaneous bowel movements per week by 3 months. Cost outcomes calculated from health-care costs and loss of salary were assessed from hospital billing and medical records and questionnaires. Primary outcome measures were the presence of a dyssynergic pattern during attempted defecation, balloon expulsion time, the number of complete spontaneous bowel movements per week, and satisfaction with bowel function, assessed by intention to treat (non-inferiority) and per protocol. This trial is registered with ClinicalTrials.gov, number NCT03202771.

FINDINGS

Of 300 patients screened we enrolled 100, from Jan 7, 2005, to Jan 31, 2010. 83 patients completed training (38 [76%] of 50 in the home-based biofeedback group and 45 [90%] of 50 in the office-based biofeedback group). 34 (68%) patients in the home-based group and 35 (70%) in the office-based group were classified as responders. All primary outcomes improved significantly from baseline in the two treatment groups (all p<0·0001). Home-based biofeedback therapy was non-inferior to office-based therapy for number of complete spontaneous bowel movements per week, satisfaction with bowel function, and balloon expulsion time in the intention-to-treat and per-protocol analyses, and for dyssynergia in the per-protocol analysis. No adverse events were reported. The median cost of home-based biofeedback therapy was significantly lower than that for office-based treatment (US$1081·70, IQR 794·90-1399·30 vs $1942·50, 1621·70-2369·00, p=0·009).

INTERPRETATION

Home-based and office-based biofeedback therapy for dyssynergic defecation improved bowel symptoms and physiology with similar efficacy. A home-based programme could substantially broaden the availability and use of this treatment.

FUNDING

National Institutes of Health.

Update on the Pathophysiology and Management of Anorectal Disorders

Anorectal disorders are common and present with overlapping symptoms. They include several disorders with both structural and functional dysfunction(s). Because symptoms alone are poor predictors of the underlying pathophysiology, a diagnosis should only be made after evaluating symptoms and physiologic and structural abnormalities. A detailed history, a thorough physical and digital rectal examination and a systematic evaluation with high resolution and/or high definition three-dimensional (3D) anorectal manometry, 3D anal ultrasonography, magnetic resonance defecography and neurophysiology tests are essential to correctly identify these conditions. These physiological and imaging tests play a key role in facilitating a precise diagnosis and in providing a better understanding of the pathophysiology and functional anatomy. In turn, this leads to better and more comprehensive management using medical, behavioral and surgical approaches. For example, patients presenting with difficult defecation may demonstrate dyssynergic defecation and will benefit from biofeedback therapy before considering surgical treatment of coexisting anomalies such as rectoceles or intussusception. Similarly, patients with significant rectal prolapse and pelvic floor dysfunction or patients with complex enteroceles and pelvic organ prolapse may benefit from combined behavioral and surgical approaches, including an open, laparoscopic, transabdominal or transanal, and/or robotic-assisted surgery. Here, we provide an update on the pathophysiology, diagnosis, and management of selected common anorectal disorders.

Refractory Constipation: What is the Clinician to Do?

Most clinicians will agree that chronic constipation is characterized by abnormal bowel movement consistency and/or frequency plus or minus evacuation symptoms, but patient perception of constipation varies widely and includes symptoms that may or may not meet official defining criteria. Although intermittent constipation is extremely common, only a small minority of patients seek care for their symptoms. Among these patients, dissatisfaction with the currently available laxative options is not uncommon, and many patients will require specialized care for severe or refractory symptoms-especially those with abdominal pain, irritable bowel syndrome overlap, bloating or distention, and psychological comorbidities. This review outlines a physiological assessment of the patient with refractory constipation, exploring treatment options among patients with slow transit, rectal evacuation disorders, and normal transit. In addition, we explore nonlaxative approaches to normal-transit patients bothered by ongoing symptoms, with an emphasis on the biopsychosocial model of functional gastrointestinal disease and treatment of visceral hypersensitivity using neuromodulators. Finally, we propose a comprehensive evaluation algorithm for the management of patients with refractory slow-transit constipation considering surgery and examine surgical options including colectomy and cecostomy using an antegrade continent enema.

Plecanatide: a new guanylate cyclase agonist for the treatment of chronic idiopathic constipation

Chronic constipation affects millions of Americans, consumes significant healthcare resources, and significantly affects quality of life (QOL). Recently, several new treatment options have become available for the treatment of constipation, including intestinal secretagogues such as lubiprotone, and linaclotide, prokinetics such as prucalopride, and bile acid transporter antagonists. Plecanatide is the newest of the secretagogue class of compounds that has been approved by the US Food and Drug Administration for the treatment of adults with chronic idiopathic constipation (CIC) in the USA. It is a guanylate cyclase agonist, and a 16 amino acid synthetic peptide that is a structural analog of human uroguanylin. Two large randomized, double-blind, placebo-controlled studies assessed the efficacy and safety of plecanatide in CIC patients (Rome III). Both doses of plecanatide, 3 mg and 6 mg resulted in a significantly greater percentage of patients who were durable overall complete spontaneous bowel movement (CSBM) responders (primary endpoint) compared with those who received placebo (plecanatide 3 mg, 21.0%; plecanatide 6 mg, 19.5%; placebo, 10.2%; p < 0.001 for each drug dose versus placebo). Plecanatide treatment also significantly reduced the severity of other CIC symptoms (straining effort, stool consistency, bloating). Also, plecanatide-treated patients reported high levels of satisfaction and improved QOL and desire to continue treatment. The rate of treatment-emergent adverse events with plecanatide was low, including rates of diarrhea (5%). Plecanatide is a luminally acting secretagogue that is efficacious and safe for the treatment of CIC. This article provides an overview of plecanatide in the management of adults with CIC.

Factors Associated With Response to Biofeedback Therapy for Dyssynergic Defecation

BACKGROUND & AIMS

Biofeedback therapy is effective for dyssynergic defecation (DD), but it is not widely available or reimbursed, and is labor intensive. It is therefore important to select the appropriate patients for this treatment. We investigated symptoms and demographic, manometric, and other factors associated with outcomes of biofeedback therapy in patients with DD.

METHODS

We performed a post hoc analysis of 2 prospective studies of biofeedback therapy in 127 adult outpatients (18-75 years old, 120 female) with chronic constipation who failed to respond to treatment with dietary fiber or laxatives (>1 year) and were diagnosed with DD based on standard criteria. In each study, patients received 1-hour, biweekly office biofeedback therapy (6 sessions) or home biofeedback therapy with a device. A therapist used visual feedback, postural, and diaphragmatic breathing techniques to teach subjects to improve defecation. Treatment success was defined by a composite of normalization of dyssynergia pattern and increase of 20 mm in baseline bowel satisfaction score. Factors were compared between the treatment success and failure groups. Intention-to-treat analysis was performed.

RESULTS

Of the 127 patients enrolled, 77 (61%) had treatment success. Dyssynergia was corrected in 78% of patients and bowel satisfaction improved in 64% of patients. Baseline demographic features, constipation symptoms, manometric and sensory parameters, balloon expulsion time, and colonic transit results were similar between treatment failure and success groups. Patients with lower baseline bowel satisfaction score (P = .008) and patients who used digital maneuvers (P = .04) were more likely to have successful biofeedback therapy.

CONCLUSIONS

Biofeedback therapy is successful in more than 60% of patients with DD. Patients who used digital maneuvers and patients with lower baseline levels of bowel satisfaction were more likely to have treatment success, whereas other factors were not associated with success. Biofeedback therapy should be offered to all patients with DD, irrespective of baseline symptoms or anorectal physiology findings.

Balloon Expulsion Test Does Not Seem to Be Useful for Screening or Exclusion of Dyssynergic Defecation as a Single Test

Background/Aims

Balloon expulsion test (BET) is regarded as a screening tool of dyssynergic defecation (DD). However, some patients with normal BET results may be treated effectively by biofeedback training. This study aims to validate BET as a single screening test.

Methods

Two hundred and thirty-two patients who were diagnosed with functional constipation or irritable bowel syndrome with constipation who underwent anorectal manometry (ARM) and BET at Seoul National University Hospital were enrolled. We evaluated the validity of BET based on ARM and electromyography (EMG) during biofeedback training.

Results

If BET ≤ 1 minute was defined as normal, sensitivity and negative predictive value (NPV) of BET in predicting paradoxical contraction based on ARM findings were 71.4% and 13.9%. If BET ≤ 3 minutes was defined as normal, sensitivity and NPV were 35.2% and 6.6%. Specificity and positive predictive value (PPV) of BET ≤ 3 minutes criteria were 84.8% and 93.3%. Same analysis was conducted in 107 patients who underwent EMG during biofeedback training. With 1-minute criteria, sensitivity and NPV of BET were 70.3% and 14.3%. With 3 minutes criteria, sensitivity and NPV of BET was 38.6% and 8.8%. Specificity and positive predictive values were both 100.0%.

Conclusions

Based on either ARM or EMG during biofeedback training, sensitivity was at most 71.4% and NPV was less than 15.0% irrespective of whether BET was within 1minute or within 3 minutes. BET seems to have a limitation as both a screening test for dyssynergic defecation and a simple assessment to rule out the necessity of biofeedback training.

Luminally Acting Agents for Constipation Treatment: A Review Based on Literatures and Patents

Constipation is one of the most frequently reported gastrointestinal (GI) disorders that negatively impacts quality of life and is associated with a significant economic burden to the patients and society. Traditional treatments including lifestyle modification and laxatives are often ineffective in the more severe forms of constipation and over the long term. New medications targeting at intestinal chloride channels and colonic serotonin receptors have been demonstrated effective in recent years. Emerging agents focusing on improving intestinal secretion and/or colonic motility have been shown effective in animal models and even in clinical trials. Recognization of the role of cystic fibrosis transmembrane regulator (CFTR) and calcium-activated chloride channels (CaCCs) in intestine fluid secretion and motility modulation makes CFTR and CaCCs promising molecule targets for anti-constipation therapy. Although there are multiple choices for constipation treatment, there is still a recognized need for new medications in anti-constipation therapy. The present review covers the discovery of luminally acting agents for constipation treatment described in both patents (2011–present) and scientific literatures.

Perspective on Physical Therapist Management of Functional Constipation

Functional constipation is a common bowel disorder leading to activity restrictions and reduced health-related quality of life. Typically, this condition is initially managed with prescription of laxatives or fiber supplementation, or both. However, these interventions are often ineffective and fail to address the underlying pathophysiology and impairments contributing to this condition. Physical therapists possess the knowledge and skills to diagnose and manage a wide range of musculoskeletal and motor coordination impairments that may contribute to functional constipation. Relevant anatomic, physiologic, and behavioral contributors to functional constipation are discussed with regard to specific constipation diagnoses. A framework for physical therapist examination of impairments that can affect gastrointestinal function, including postural, respiratory, musculoskeletal, neuromuscular, and behavioral impairments, is offered. Within the context of diagnosis-specific patient cases, multifaceted interventions are described as they relate to impairments underlying functional constipation type. The current state of evidence to support these interventions and patient recommendations is summarized. This perspective article aims not only to heighten physical therapists' awareness and management of this condition, but also to stimulate clinical questioning that will open avenues for future research to improve patient care.

Functional Disorders of Constipation: Paradoxical Puborectalis Contraction and Increased Perineal Descent

Paradoxical puborectalis contraction (PPC) and increased perineal descent (IPD) are subclasses of obstructive defecation. Often these conditions coexist, which can make the evaluation, workup, and treatment difficult. After a thorough history and examination, workup begins with utilization of proven diagnostic modalities such as cinedefecography and anal manometry. Advancements in technology have increased the surgeon's diagnostic armamentarium. Biofeedback and pelvic floor therapy have proven efficacy for both conditions as first-line treatment. In circumstances where PPC is refractory to biofeedback therapy, botulinum toxin injection is recommended. Historically, pelvic floor repair has been met with suboptimal results. In IPD, surgical therapy now is directed toward the potentially attendant abnormalities such as rectoanal intussusception and rectal prolapse. When these associated abnormalities are not present, an ostomy should be considered in patients with IPD as well as medically refractory PPC.

Chronic Constipation: a Review of Current Literature

Chronic constipation is a common health condition representing a substantial proportion of primary care visits and referrals to specialist providers. Chronic constipation can have a significant negative effect on health-related quality of life and has been associated with psychological distress in severely affected patients. It has the potential to cause patients to curtail work, school, and social activities. While different pathophysiological mechanisms have been implicated in the development of chronic constipation, in some instances, the causes of chronic constipation are not easily determined. Expenditures for the evaluation and management of chronic constipation represent a significant burden on patients and payers, and it is important for clinicians to have a clear understanding of the different pathophysiological mechanisms associated with constipation, understand the different testing modalities and treatments that are available including their appropriateness and limitations, and tailor that knowledge to the management of individual patients.

Diagnosis and Treatment of Dyssynergic Defecation

Dyssynergic defecation is common and affects up to one half of patients with chronic constipation. This acquired behavioral problem is due to the inability to coordinate the abdominal and pelvic floor muscles to evacuate stools. A detailed history, prospective stool diaries, and a careful digital rectal examination will not only identify the nature of bowel dysfunction, but also raise the index of suspicion for this evacuation disorder. Anorectal physiology tests and balloon expulsion test are essential for a diagnosis. Newer techniques such as high-resolution manometry and magnetic resonance defecography can provide mechanistic insights. Recently, randomized controlled trials have shown that biofeedback therapy is more effective than laxatives and other modalities, both in the short term and long term, without side effects. Also, symptom improvements correlated with changes in underlying pathophysiology. Biofeedback therapy has been recommended as the first-line of treatment for dyssynergic defecation. Here, we provide an overview of the burden of illness and pathophysiology of dyssynergic defecation, and how to diagnose and treat this condition with biofeedback therapy.

Biomarkers to distinguish functional constipation from irritable bowel syndrome with constipation

Treatments for functional constipation (FC) and irritable bowel syndrome with constipation (IBS-C) differ, but symptom criteria do not reliably distinguish between them; some regard FC and IBS-C as parts of a single constipation spectrum. Our goal was to review studies comparing FC and IBS-C to identify possible biomarkers that separate them. A systematic review identified 15 studies that compared physiologic tests in FC vs IBS-C. Pain thresholds were lower in IBS-C than FC for 3/5 studies and not different in 2/5. Colonic motility was decreased more in FC than IBS-C for 3/3 studies, and whole gut transit was delayed more in FC than IBS-C in 3/8 studies and not different in 5/8. Pelvic floor dyssynergia was unrelated to diagnosis. Sympathetic arousal, measured in only one study, was greater in IBS-C than FC. The most reliable separation of FC from IBS-C was shown by a novel new magnetic resonance imaging technique described in this issue of the journal. These authors showed that drinking one liter of polyethylene glycol laxative significantly increased water content in the small intestine, volume of contents in the ascending colon, and time to first evacuation in FC vs IBS-C; and resulted in less colon motility and delayed whole gut transit in FC compared to IBS-C. Although replication is needed, this well-tolerated, non-invasive test promises to become a new standard for differential diagnosis of FC vs IBS-C. These data suggest that FC and IBS-C are different disorders rather than points on a constipation spectrum.

Bowel Disorders

Functional bowel disorders are highly prevalent disorders found worldwide. These disorders have the potential to affect all members of society, regardless of age, gender, race, creed, color or socioeconomic status. Improving our understanding of functional bowel disorders (FBD) is critical as they impose a negative economic impact to the global health care system in addition to reducing quality of life. Research in the basic and clinical sciences during the past decade has produced new information on the epidemiology, etiology, pathophysiology, diagnosis and treatment of FBDs. These important findings created a need to revise the Rome III criteria for FBDs, last published in 2006. This manuscript classifies the FBDs into five distinct categories: irritable bowel syndrome (IBS); functional constipation (FC); functional diarrhea (FDr); functional abdominal bloating/distention (FAB/D); and unspecified FBD (U-FBD). Also included in this article is a new sixth category, opioid induced constipation (OIC) which is distinct from the functional bowel disorders (FBDs). Each disorder will first be defined, followed by sections on epidemiology, rationale for changes from prior criteria, clinical evaluation, physiologic features, psychosocial features and treatment. It is the hope of this committee that this new information will assist both clinicians and researchers in the decade to come.

Clinical utility of colonic manometry in slow transit constipation

BACKGROUND

The clinical significance of colorectal sensorimotor evaluation in patients with slow transit constipation (STC) is unclear. We investigated whether colonic manometric evaluation is useful for characterizing colonic sensorimotor dysfunction and for guiding therapy in STC.

METHODS

24-h ambulatory colonic manometry was performed in 80 patients (70 females) with STC by placing a six sensor solid-state probe, along with assessment of colonic sensation with barostat. Anorectal manometry was also performed. Manometrically, patients were categorized as having colonic neuropathy or myopathy based on gastrocolonic response, waking response and high amplitude propagated contractions (HAPC); and based on colonic sensation, as colonic hyposensitivity or hypersensitivity. Clinical response to pharmacological, biofeedback, and surgical treatment was assessed at 1 year and correlated with manometric findings.

KEY RESULTS

Forty seven (59%) patients who had abnormal colonic manometry, with features suggestive of neuropathy (26%), and myopathy (33%); 41% had normal colonic manometry. Patients who had abnormal colonic sensation were 74% and 61% had overlapping dyssynergic defecation. Patients with neuropathy were more likely to have colonic hyposensitivity. Sixty-four percent of patients with colonic myopathy or normal manometry improved with medical/biofeedback therapy when compared to 15% with colonic neuropathy (P < 0.01). Selected patients with colonic neuropathy had excellent response to surgery, but many developed bacterial overgrowth.

CONCLUSIONS & INFERENCES

Colonic manometry demonstrates significant colonic sensorimotor dysfunction in STC patients and reveals considerable pathophysiological heterogeneity. It can be useful for characterizing the underlying pathophysiology and for guiding clinical management in STC, especially surgery.

Fiber and functional gastrointestinal disorders

Despite years of advising patients to alter their dietary and supplementary fiber intake, the evidence surrounding the use of fiber for functional bowel disease is limited. This paper outlines the organization of fiber types and highlights the importance of assessing the fermentation characteristics of each fiber type when choosing a suitable strategy for patients. Fiber undergoes partial or total fermentation in the distal small bowel and colon leading to the production of short-chain fatty acids and gas, thereby affecting gastrointestinal function and sensation. When fiber is recommended for functional bowel disease, use of a soluble supplement such as ispaghula/psyllium is best supported by the available evidence. Even when used judiciously, fiber can exacerbate abdominal distension, flatulence, constipation, and diarrhea.

The physiology of human defecation

Human defecation involves integrated and coordinated sensorimotor functions, orchestrated by central, spinal, peripheral (somatic and visceral), and enteric neural activities, acting on a morphologically intact gastrointestinal tract (including the final common path, the pelvic floor, and anal sphincters). The multiple factors that ultimately result in defecation are best appreciated by describing four temporally and physiologically fairly distinct phases. This article details our current understanding of normal defecation, including recent advances, but importantly identifies those areas where knowledge or consensus is still lacking. Appreciation of normal physiology is central to directed treatment of constipation and also of fecal incontinence, which are prevalent in the general population and cause significant morbidity.

Diagnosis and treatment of chronic constipation--a European perspective

BACKGROUND

Although constipation can be a chronic and severe problem, it is largely treated empirically. Evidence for the efficacy of some of the older laxatives from well-designed trials is limited. Patients often report high levels of dissatisfaction with their treatment, which is attributed to a lack of efficacy or unpleasant side-effects. Management guidelines and recommendations are limited and are not sufficiently current to include treatments that became available more recently, such as prokinetic agents in Europe.

PURPOSE

We present an overview of the pathophysiology, diagnosis, current management and available guidelines for the treatment of chronic constipation, and include recent data on the efficacy and potential clinical use of the more newly available therapeutic agents. Based on published algorithms and guidelines on the management of chronic constipation, secondary pathologies and causes are first excluded and then diet, lifestyle, and, if available, behavioral measures adopted. If these fail, bulk-forming, osmotic, and stimulant laxatives can be used. If symptoms are not satisfactorily resolved, a prokinetic agent such as prucalopride can be prescribed. Biofeedback is recommended as a treatment for chronic constipation in patients with disordered defecation. Surgery should only be considered once all other treatment options have been exhausted.

Prucalopride: the evidence for its use in the treatment of chronic constipation

Introduction:

Chronic constipation is a common condition that is difficult to treat. Existing options for the treatment of patients with different subgroups of constipation are limited. A new efficacious and safe drug is needed to limit the frequently observed adverse effects induced by laxatives, to improve general wellbeing and quality of life, and to provide an alternative for enemas or even resectional surgery in patients in whom stimulant laxatives cause disabling adverse effects or fail to increase bowel movement frequency.

Aims:

The purpose of this article is to assess the current evidence supporting the use of the selective and high affinity serotonin-4 (5-HT₄) receptor agonist prucalopride in the management of chronic constipation.

Evidence review:

There are now convincing data from phase II and multicenter phase III randomized, double-blind, placebo-controlled trials that prucalopride treatment results in a clinically meaningful increase in the number of spontaneous complete bowel movements, a reduction of perceived severity of symptoms and improved disease-related quality of life in a significant proportion of patients. There is a rapid onset of the effect and the improvement is maintained for at least 12 weeks.

Prucalopride in a dose of up to 4 mg per day appeared generally well tolerated and devoid of serious cardiac events. Adverse events, most frequently headache and nausea, are usually mild or moderate and occur mainly during the first days of treatment. Prucalopride should be used with prudence and with careful assessment of the benefit-risk ratio until more clinical and electrophysiologic data become available, because relatively few patients have been exposed to the drug for long periods of time.

Place in therapy:

Prucalopride 1–2 mg once daily may be given to patients suffering from chronic constipation for whom laxatives do not provide adequate relief of their symptoms. Patients with severe constipation and slow transit, who frequently develop tolerance to stimulant laxatives, are also eligible for prucalopride treatment.

Gastrointestinal issues in the older female patient

As the body ages, it undergoes a multitude of changes. Some of these changes are visible, whereas others are not and may be elicited during the patient encounter. Some gastrointestinal issues may be more common in the elderly population and possibly in older women. These issues range from motility disorders, such as fecal incontinence and constipation, to changes in neuropeptide function and its effect on the anorexia of aging. This article comprehensively reviews gastrointestinal issues that commonly afflict the elderly female population.

Rectal sensorimotor dysfunction in constipation

The pathophysiological mechanisms underlying chronic constipation in both adults and children remain to be unravelled. This is a not inconsiderable challenge, but is fundamental to improving management of such patients. Rectal sensorimotor function, which encompasses both sensation and motility, as well as biomechanical components (compliance, capacity), is now strongly implicated in the pathogenesis of constipation. Rectal hyposensitivity, rectal hypercompliance, increased rectal capacity, rectal motor dysfunction (phasic contractility and tone), and altered rectoanal reflex activity are all found in constipated patients, particularly in association with 'functional' disorders of defaecation (i.e. pelvic floor dyssynergia). This review covers contemporary understanding of how components of rectal sensorimotor function may contribute to symptom development in both adult and paediatric populations. The complex interaction between sensory/motor/biomechanical domains, and how best to measure these functions are addressed, and where data exist, the impact of sensorimotor dysfunction on therapeutic outcomes is highlighted.

Long-term efficacy of biofeedback therapy for dyssynergic defecation: randomized controlled trial

OBJECTIVES

Although biofeedback therapy is effective in the short-term management of dyssynergic defecation, its long-term efficacy is unknown. Our aim was to compare the 1-year outcome of biofeedback (manometric-assisted pelvic relaxation and simulated defecation training) with standard therapy (diet, exercise, laxatives) in patients who completed 3 months of either therapy.

METHODS

Stool diaries, visual analog scales (VASs), colonic transit, anorectal manometry, and balloon expulsion time were assessed at baseline, and at 1 year after each treatment. All subjects were seen at 3-month intervals and received reinforcement. Primary outcome measure (intention-to-treat analysis) was a change in the number of complete spontaneous bowel movements (CSBMs) per week. Secondary outcome measures included bowel symptoms, changes in dyssynergia, and anorectal function.

RESULTS

Of 44 eligible patients with dyssynergic defecation, 26 agreed to participate in the long-term study. All 13 subjects who received biofeedback, and 7 of 13 who received standard therapy, completed 1 year; 6 failed standard therapy. The number of CSBMs per week increased significantly (P<0.001) in the biofeedback group but not in the standard group. Dyssynergia pattern normalized (P<0.001), balloon expulsion time improved (P=0.0009), defecation index increased (P<0.001), and colonic transit time normalized (P=0.01) only in the biofeedback group.

CONCLUSIONS

Biofeedback therapy provided sustained improvement of bowel symptoms and anorectal function in constipated subjects with dyssynergic defecation, whereas standard therapy was largely ineffective.

Pathophysiology of evacuation disorders

This review details our contemporary knowledge of the mechanisms underlying evacuatory disorders. There is confusion concerning terminology and classification, which is based upon both an incomplete understanding of the multiple mechanisms involved in evacuation, and that current tests to investigate it are not physiological. Nevertheless, despite the need for more research, significant advances have been made and current assessments can direct therapy.

No role for increased rectal compliance in pediatric functional constipation

BACKGROUND & AIMS

Increased rectal compliance has been proposed to contribute to pediatric functional constipation (FC). We evaluated the clinical relevance of increased rectal compliance and assessed whether regular use of enemas improves rectal compliance in children with FC.

METHODS

A prospective longitudinal study was conducted on children (8-18 years old) with FC. Pressure-controlled rectal distensions were performed at baseline and at 1 year. Rectal compliance was categorized into 3 groups: normal, moderately increased, or severely increased. Patients were randomly assigned to groups given conventional therapy or rectal enemas and conventional therapy. Clinical success was defined as >or=3 spontaneous defecations per week and fecal incontinence <1 per week.

RESULTS

Baseline measurements were performed in 101 children (11.0 +/- 2.1 years); rectal compliance was normal in 36%, moderately increased in 40%, and severely increased in 24%. Patients with severely increased rectal compliance had lower defecation frequency (P = .03), more fecal incontinence (P = .04), and more rectal fecal impaction (P < .001). After 1 year, success values were similar between groups: 42% normal, 41% moderately increased, and 40% with severely increased compliance. Barostat studies performed after 1 year in 80 children (37 conventional therapy and 43 rectal enemas in addition to conventional therapy) revealed that rectal compliance had not changed in either group and had not improved in successfully treated patients.

CONCLUSIONS

Constipated children with severely increased rectal compliance have severe symptoms. However, increased rectal compliance is not related to treatment failure. Regular use of enemas to avoid rectal fecal impaction does not improve rectal compliance in pediatric FC.

Chronic constipation: overview and challenges

Despite its high prevalence and cost implications, our understanding of the pathophysiology of constipation remains primitive, and available therapies have limited efficacy. The purpose of this supplement is to address critically the reasons for the current lack of understanding and to propose avenues of future research to address these deficiencies.

Constipation in old age

The prevalence of constipation increases with age. However, constipation is not a physiological consequence of normal ageing. Indeed, the aetiology of constipation in older people is often multifactorial with co-morbid diseases, impaired mobility, reduced dietary fibre intake and prescription medications contributing significantly to constipation in many instances. A detailed clinical history and physical examination including digital rectal examination is usually sufficient to uncover the causes of constipation in older people; more specialized tests of anorectal physiology and colonic transit are rarely required. The scientific evidence base from which to develop specific treatment recommendations for constipation in older people is, for the most part, slim. Constipation can be complicated by faecal impaction and incontinence, particularly in frail older people with reduced mobility and cognitive impairment; preventative strategies are important in those at risk.

Small bowel motility in functional chronic constipation

In functional constipation, three pathophysiological subgroups have been identified: slow-transit constipation (STC); normal-transit constipation (NTC) and outlet delay (OD). Extracolonic manifestations, especially disturbed small bowel motility, are well known to occur in STC, but have rarely been studied in NTC and OD. To perform 24-h-ambulatory jejunal manometry in a large prospective series of clinical patients with chronic constipation of all subtypes. A total of 61 consecutive patients, referred to our tertiary gastroenterologic centre for chronic constipation (48 female, 13 male; mean age 57 (range 20-87) years), underwent jejunal 24-h-ambulatory manometry (standardized meal) after a transit-time study (radio-opaque markers), anorectal manometry, defecography and colonoscopy. Computerized and visual analysis by two independent observers was compared with the normal range of manometric variables, defined by data previously obtained in 50 healthy subjects (Gut 1996;38:859). Five patients were excluded from the study because of coexistence of OD and STC. No patient with OD (n = 8), but all patients with STC (n = 32) and 94% of patients with NTC (n = 16) showed small bowel motor abnormalities; both in postprandial response and fasting motility. The abnormal findings ranged from severe disturbances with complete loss of MMC to subtle changes of contraction parameters that could only be assessed by computerized analysis. No significant differences between STC- and NTC-patients were found. Most findings pointed to an underlying enteric neuropathy. Intestinal prolonged-ambulatory manometry adds valuable information to the pathophysiologic understanding of functional chronic constipation of STC- and NTC-type, however there are no distinct manometric features to differentiate between both.

A new technique for suture rectopexy without resection for rectal prolapse

BACKGROUND

We surmised that if rectopexy was performed without dissection of the lateral rectal stalks in patients with full-thickness rectal prolapse and normal preoperative transit, sigmoid resection may not be required. This study evaluated a new approach to abdominal suture rectopexy for rectal prolapse.

METHODS

A total of 81 patients (57 male, 24 female; median age 37 years, range 5-82 years) with rectal prolapse were assessed by clinical examination, anal manometry (maximum resting pressure, MRP, and squeeze pressure, MSP) and radioopaque marker transit studies. Of the 81 patients, 70 with normal preoperative transit underwent suture fixation alone, without resection, performed under spinal anaesthesia, through a 7-cm transverse left lower quadrant incision gaining access to the presacral space via a left pararectal "window", preserving the lateral stalks.

RESULTS

Average surgical time was 50 min, mortality was zero, and morbidity was 9% (three patients with wound infection, four with urinary retention). Anal incontinence improved in 43 of 53 patients (81%, p=0.001). MRP and MSP had improved at 3 months after surgery: MRP from a mean of 27.6+/-1.4 mmHg (range 2-30 mmHg) before surgery to 32.5+/-2.21 mmHg (2-60 mmHg) after surgery (p=0.008); MSP from 69.25+/-6.4 mmHg (8-153 mmHg) before surgery to 79+/-4.77 mmHg (35-157 mmHg) after surgery (p=0.001).. Transit was unchanged in 18 of 20 patients (90%) who were evaluated before and after surgery; none was constipated after surgery. At 56 months, prolapse had recurred in five patients (7%).

CONCLUSION

Abdominal suture rectopexy with a left pararectal approach without sigmoid resection in those with normal preoperative transit resulted in an improvement in anal incontinence and satisfactory long-term control of prolapse. The operation did not alter transit and did not result in significant constipation.

Management of chronic constipation in the elderly

Constipation is a significant healthcare problem in the elderly. However, while undoubtedly common in the elderly, data on the prevalence of constipation in general and of its subtypes vary considerably, depending on the nature of the study population and their location. Furthermore, the complexity of the pathophysiology of constipation in this age group is little appreciated. Assumptions regarding 'age-related changes in colorectal physiology' are, for the most part, not supported by scientific evidence and may serve to distract the clinician from uncovering the contributions of co-morbid diseases and the impact of iatrogenic factors. The evidence base from which one can develop recommendations on the management of constipation in the elderly is, for the most part, slim. This becomes most starkly apparent when one attempts to critically assess specific approaches to management. There is insufficient evidence to support the use of many commonly used laxatives both in the general population and in the elderly. Lifestyle interventions have value for some patients but data are lacking on the benefits of these interventions for patients with chronic constipation. Data in the elderly do not exist for most new pharmacological approaches to constipation. Pending the availability of good data, management of constipation in the elderly should be tailored to each individual's needs and expectations, regardless of age or place of residence. In certain situations, constipation may be complicated by the development of impaction; preventive strategies are important in this context. We urge enrolment of many more elderly individuals with chronic constipation in clinical trials designed to address their particular needs.

Constipation: evaluation and treatment of colonic and anorectal motility disorders

This article focuses on the colonic and anorectal motility disturbances that are associated with chronic constipation and their management. Functional chronic constipation consists of three overlapping subtypes: slow transit constipation, dyssynergic defecation, and irritable bowel syndrome with constipation. The Rome criteria may serve as a useful guide for making a clinical diagnosis of functional constipation. Today, an evidence-based approach can be used to treat patients with chronic constipation. The availability of specific drugs for the treatment of chronic constipation, such as tegaserod and lubiprostone, has enhanced the therapeutic armamentarium for managing these patients. Randomized controlled trials have also established the efficacy of biofeedback therapy in the treatment of dyssynergic defecation.

Clinical presentation and patterns of slow transit constipation do not predict coexistent upper gut dysmotility

BACKGROUND

Slow transit constipation (STC) is associated with upper gastrointestinal tract motor abnormalities in a subset of patients. This could influence the clinical approach, particularly in those rare cases where surgical management is considered.

AIMS

To identify factors that predict proximal gut dysmotility in patients with STC.

METHODS

Esophageal and small bowel motor function were evaluated in 77 patients with STC. Severity and pattern of colonic transit delay, prevalence of a co-existent rectal evacuatory disorder, and type (if present), and duration, and onset of constipation symptoms were compared.

RESULTS

Of the 77 patients studied, 43% exhibited altered motor function in the esophagus and/or small bowel. Frequency of defecation was lower in these patients than in those without upper gastrointestinal dysmotility (0.5 +/- 0.1 vs. 1.3 +/- 0.3 bowel movements/per week, respectively; P = 0.04). Severity and patterns of colonic transit delay and the mechanism associated with the onset of constipation symptoms or with their duration were similar in subjects with or without upper gastrointestinal tract dysmotility. Small bowel but not esophageal motor dysfunction was more frequently associated with a co-existent rectal evacuatory disorder (P = 0.01).

CONCLUSION

Upper gastrointestinal tract dysmotility in patients with STC is frequent, but prediction on the basis of clinical history and characteristics of colonic transit is problematic.

Lubiprostone for chronic idiopathic constipation and irritable bowel syndrome with constipation

Lubiprostone, a locally acting highly selective type-2 chloride channel activator, has been US FDA approved since January 2006 for the treatment of adults with chronic idiopathic constipation and FDA approved since April 2008 for the treatment of woman aged 18 years or older suffering from irritable bowel syndrome (IBS) with constipation. Through activation of the type-2 chloride channels located on the luminal side of intestinal epithelial cells, it promotes fluid secretion, increasing the liquid content of stool and accelerating small bowel as well as colonic transit. Lubiprostone has demonstrated efficacy with respect to increasing weekly spontaneous bowel movements and improving stool consistency, straining and constipation severity, both in short- and long-term studies. It has also demonstrated efficacy in the treatment of IBS with constipation, with beneficial effects on global symptoms, abdominal pain, constipation-related symptoms and overall quality of life. There is no evidence of a rebound in constipation or IBS symptoms following cessation of lubiprostone. In general, lubiprostone is well tolerated, with the most common side effects including nausea, headache and diarrhea.

[The Latin-American Consensus on Chronic Constipation]

The Latin-American Consensus on Chronic Constipation aimed to establish guidelines to improve the identification, diagnosis and treatment of this disorder in the region. Two coordinators and an honorary coordinator established the process and the topics to be discussed, based on a systematic review of the literature published in the previous 10 years, since 1995. Seventeen members participated with the support of their local gastroenterology societies. The members reviewed the different subjects based on the levels of evidence and grades of recommendation; the topics were then discussed in a plenary session. A written report was drafted and the coordinators prepared the final declarations to be submitted to a vote by all the members in October 2006. The consensus concluded that chronic constipation has an estimated prevalence of 5-21% in the region, with a female-to-male ratio of 3:1. Among individuals with constipation, 75% use some type of medication, with more than 50% using home remedies. A diagnosis based on Rome Criteria was recommended and diagnostic testing only in persons older than 50 years or with alarm symptoms. The use of barium enema as an initial investigation was recommended only in countries with a high prevalence of idiopathic megacolon or Chagas' disease. Recommendations on treatment included an increase in dietary fiber of up to 25-30 g/day (grade C). No evidence was found to recommend measures such as exercise, increased water intake, or frequent visits to the toilet. Fiber supplements such as Psyllium received a grade B and pharmacological treatments such as tegaserod and polyethylene glycol, both grade A. There was insufficient evidence to recommend lactulose, but the consensus did not disadvise its use when necessary. Complementary investigations such as colonic transit followed by anorectal manometry and defecography were only recommended to rule out colonic inertia and/or obstructive defecation in patients not responding to treatment. Biofeedback was recommended (grade B) for those with pelvic dyssynergia.

Functional defecation disorder as a clinical subgroup of chronic constipation: analysis of symptoms and physiological parameters

OBJECTIVE

Patients with functional constipation can be classified according to symptoms and physiological parameters as either having a disorder of defecation or having normal defecation. It is hypothesized that the disordered defecation, where it exists, is a causative factor of the constipation. However, the utility of this classification has yet to be proven in terms of predicting response to therapy. The definitions are non-specific and based on tests that are done in an artificial setting and with derived normal ranges. It is therefore possible that the symptoms and physiological parameters of a defecatory disorder may occur as a continuous spectrum in these patients, rather than defining a discrete entity or subtype. The aim of this study was to use cluster analysis and factor analysis of defecatory symptoms and physiological parameters to look for evidence of subgroups in patients with functional constipation.

MATERIAL AND METHODS

Consecutive patients presenting to a specialist constipation clinic and satisfying the inclusion criteria were assessed to determine the severity of defecatory symptoms, and underwent isotope defecating proctography and the Sitzmark transit study. Assessments were made contemporaneously and results of any test not performed within 6 weeks of the initial assessment were excluded. Principle components analysis and cluster analysis were performed to look for evidence of subgroups. Relationships between evacuatory symptoms, index parameters, and test results were explored. The detailed and unselected nature of the analyses produced hundreds of test results, and statistically significant results were critically evaluated in this context.

RESULTS

A total of 116 patients were studied (age range 18-73 years, mean 40.5 years). Based on the results of the transit study and proctography, 38% of patients showed evidence of slow transit constipation, 20% FDD (functional defecation disorder), 29% both, and 12% neither. Principle components analysis did not demonstrate an obvious dimension reduction for the variables tested. Cluster analysis (over 150 solutions tested) failed to show evidence of clustering. There were no useful predictive relationships between evacuatory symptoms, index parameters and test results.

CONCLUSIONS

We used multiple statistical analyses to look for clustering and predictive relationships between clinical and physiological parameters in consecutive patients with functional constipation and found no evidence of the existence of a subgroup of patients with a defecatory disorder. This may be due to weaknesses in the study design, poor validity of the assessments performed, or that defecatory features do not identify a distinct pathophysiological entity, but rather are manifested variably as a continuous spectrum.