Misoprostol in the treatment of chronic refractory constipation: results of a long-term open label trial

Idiopathic Slow Transit Constipation: Pathophysiology, Diagnosis, and Management

Slow transit constipation (STC) has an estimated prevalence of 2-4% of the general population, and although it is the least prevalent of the chronic constipation phenotypes, it more commonly causes refractory symptoms and is associated with significant psychosocial stress, poor quality of life, and high healthcare costs. This review provides an overview of the pathophysiology, diagnosis, and management options in STC. STC occurs due to colonic dysmotility and is thought to be a neuromuscular disorder of the colon. Several pathophysiologic features have been observed in STC, including reduced contractions on manometry, delayed emptying on transit studies, reduced numbers of interstitial cells of Cajal on histology, and reduced amounts of excitatory neurotransmitters within myenteric plexuses. The underlying aetiology is uncertain, but autoimmune and hormonal mechanisms have been hypothesised. Diagnosing STC may be challenging, and there is substantial overlap with the other clinical constipation phenotypes. Prior to making a diagnosis of STC, other primary constipation phenotypes and secondary causes of constipation need to be ruled out. An assessment of colonic transit time is required for the diagnosis and can be performed by a number of different methods. There are several different management options for constipation, including lifestyle, dietary, pharmacologic, interventional, and surgical. The effectiveness of the available therapies in STC differs from that of the other constipation phenotypes, and prokinetics often make up the mainstay for those who fail standard laxatives. There are few available management options for patients with medically refractory STC, but patients may respond well to surgical intervention. STC is a common condition associated with a significant burden of disease. It can present a clinical challenge, but a structured approach to the diagnosis and management can be of great value to the clinician. There are many therapeutic options available, with some having more benefits than others.

Exploring Pharmacological Treatments for Chronic Idiopathic Constipation in Adults: A Look Back to the Future

Despite great progress in pharmaceutical research, the medical treatment of chronic idiopathic constipation is far from ideal. The aim of the present article was to review literature data, focusing on poorly studied or commercially unavailable/unapproved drugs potentially useful for the treatment of chronic idiopathic constipation in adults. An extensive online literature search was conducted using the keywords "chronic constipation", "colon", "constipation", "drugs", "laxatives", and "treatment", in various combinations between January 1960 and December 2022. The literature search showed the presence of some drugs whose efficacy has only recently been demonstrated by modern investigations, and which are likely to be incorporated into future guidelines, of others that are proven effective and potentially effective on constipated patients but limited by small or relatively old studies, or by side effects which could be used in experienced hands, and of others that might be useful but lack a solid scientific background. Looking into the future for patients with chronic constipation might add some more tools to the therapeutic portfolio, especially for certain subgroups of these patients.

Chronic Idiopathic Constipation in Adults: A Review on Current Guidelines and Emerging Treatment Options

Chronic idiopathic constipation (CIC) is a common functional bowel disorder characterized by difficult, infrequent, and/or incomplete defecation. It has a great impact on the quality of life and on health care system and represents a heavy economic burden. The diagnosis is based on symptoms, classified by the Rome IV criteria. The aim of this review was to evaluate the current therapeutic guidelines for adult CIC and highlight new emerging treatments. In detail, European, French, Spanish and Korean guidelines have been identified and compared. Osmotic laxatives, and in particular polyethylene glycol, represent the first-line therapeutic approach. Stimulant laxatives are recommended as a second-line therapy. Pelvic floor rehabilitation is recommended in patients with ano-rectal dyssynergia. In patients who fail to improve with pharmacological therapies sacral nerve stimulation is considered as last chance before surgery. Surgical approach has however limited indications in selected cases. Inertia coli refractory to any approach and obstructed defecation are two subtypes which can benefit from surgery. Among emerging agents, prucalopride, a prokinetic agent, is recommended as a second-line treatment in refractory CIC patients. In addition, the secretagogues linaclotide and plecanatide and the bile acid transported inhibitor elobixibat can be effective in patients not responsive to a second-line therapeutic regimen, although they are not worldwide commercially available.

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.

Pharmacological treatment for antipsychotic-related constipation

BACKGROUND

Antipsychotic-related constipation is a common and serious adverse effect, especially for people taking clozapine. Clozapine has been shown to impede gastrointestinal motility, leading to constipation, and has been reported in up to 60% of patients receiving clozapine. In rare cases, complications can be fatal. Appropriate laxatives should be prescribed to treat constipation in people taking antipsychotics, but there is a lack of guidance on the comparative effectiveness and harms of different agents in this population. An understanding of the effectiveness and safety of treatment for antipsychotic-related constipation is important for clinicians and patients alike.

OBJECTIVES

To evaluate the effectiveness and safety of pharmacologic treatment (versus placebo or compared against another treatment) for antipsychotic-related constipation (defined as constipated patients of any age, who are treated with antipsychotics, regardless of dose, in which constipation is considered to be an antipsychotic-related side effect).

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Trials Register (15 June 2015), which is based on regular searches of MEDLINE, Embase, CINAHL, BIOSIS, AMED, PubMed, PsycINFO, and registries of clinical trials, grey literature, and conference proceedings. There are no language, date, document type, or publication status limitations for inclusion of records in this register. We also handsearched bibliographies and contacted relevant authors for additional information.

SELECTION CRITERIA

We included all published and unpublished randomised controlled trials (RCTs) investigating the efficacy of pharmacological treatments in patients with antipsychotic-related constipation. Pharmacological treatments included laxatives and other medicines that could reasonably be used to combat constipation in this population (e.g. anticholinergic agents, like bethanecol).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from all included studies and assessed trials for risk of bias. A third author reviewed 20% of trials. We analysed dichotomous data using relative risks (RR) and the 95% confidence intervals (CI). We assessed risk of bias for included studies and used GRADE to create a 'Summary of findings' table. We discussed any disagreement, documented decisions, and attempted to contact study authors when necessary.

MAIN RESULTS

We identified two relevant Chinese studies (N = 480) that contributed data to this review. Both studies were over ten years old and poorly reported, lacking descriptions of contemporary CONSORT reporting prerequisites, such as sequence generation, allocation concealment, blinding, participant flow, how the sample size was determined, or how outcomes were measured. The studies also did not report trial registration, pre-specified protocols, consent processes, ethical review, or funding source. We were unsuccessful in making contact with the authors to clarify the missing details. We classified both studies as having an overall high risk of bias.One study compared glycerol suppository with the traditional Chinese medicine (TCM) approaches of tuina massage and acupuncture. Compared to tuina massage, glycerol laxative was less effective in relieving constipation at both two days after treatment (1 RCT; N = 120; RR 2.88, 95% CI 1.89 to 4.39; very low-quality evidence), and three days (1 RCT; N = 120; RR 4.80, CI 1.96 to 11.74, very low-quality evidence). Favourable results were also seen for acupuncture at two days (1 RCT; N = 120; RR 3.50; 95% CI 2.18 to 5.62; very low-quality evidence), and at three days (1 RCT; N = 120; RR 8.00, 95% CI 2.54 to 25.16; very low-quality evidence).The other study compared mannitol, an osmotic laxative, with rhubarb soda or phenolphthalein. Mannitol was more effective than rhubarb soda or phenolphthalein in trelieving constipation within 24 hours of treatment (1 RCT; N = 240; RR 0.07; 95% CI 0.02 to 0.27, very low-quality evidence).No data were reported for our other important outcomes: need for rescue medication, bowel obstruction (a complication of antipsychotic-related constipation), quality of life, adverse events, leaving the study early, and economic costs.

AUTHORS' CONCLUSIONS

We had hoped to find clinically useful evidence appraising the relative merits of the interventions routinely used to manage antipsychotic-related constipation, a common and potentially serious adverse effect of the use of these drugs. The results were disappointing. There were no data comparing the common pharmacological interventions for constipation, such as lactulose, polyethylene glycol, stool softeners, lubricant laxatives, or of novel treatments such as linaclotide. Data available were very poor quality and the trials had a high risk of bias. Data from these biased studies suggested that mannitol, an osmotic laxative, was more effective than rhubarb soda and phenolphthalein in relieving constipation, and a two-week course of glycerol suppositories was less effective than the TCM approaches of tuina massage and acupuncture.Overall, there is insufficient trial-based evidence to assess the effectiveness and safety of pharmacological interventions for treating antipsychotic-related constipation, due to limited, poor quality data (few studies with high risk of bias and no meta-analyses). The methodological limitations in the included studies were obvious, and any conclusions based on their results should be made with caution. Methodologically rigorous RCTs evaluating interventions for treating antipsychotic-related constipation are needed.

Gastrointestinal Dysfunctions in Parkinson's Disease: Symptoms and Treatments

A diagnosis of Parkinson's disease is classically established after the manifestation of motor symptoms such as rigidity, bradykinesia, and tremor. However, a growing body of evidence supports the hypothesis that nonmotor symptoms, especially gastrointestinal dysfunctions, could be considered as early biomarkers since they are ubiquitously found among confirmed patients and occur much earlier than their motor manifestations. According to Braak's hypothesis, the disease is postulated to originate in the intestine and then spread to the brain via the vagus nerve, a phenomenon that would involve other neuronal types than the well-established dopaminergic population. It has therefore been proposed that peripheral nondopaminergic impairments might precede the alteration of dopaminergic neurons in the central nervous system and, ultimately, the emergence of motor symptoms. Considering the growing interest in the gut-brain axis in Parkinson's disease, this review aims at providing a comprehensive picture of the multiple gastrointestinal features of the disease, along with the therapeutic approaches used to reduce their burden. Moreover, we highlight the importance of gastrointestinal symptoms with respect to the patients' responses towards medical treatments and discuss the various possible adverse interactions that can potentially occur, which are still poorly understood.

Opioid-induced bowel dysfunction: epidemiology, pathophysiology, diagnosis, and initial therapeutic approach

Opioids affect motor and sensory function throughout the gastrointestinal tract, and are frequently associated with a number of gastrointestinal symptoms including constipation, which impairs the quality of life and may limit the dose of opioid or result in discontinuation altogether. Patients with opioid-induced constipation should be assessed by careful history and physical examination, and in some cases where the diagnosis is unclear with select diagnostic tests. Few clinical studies have been conducted to assess the efficacy of various treatments. However, it is generally recommended that first-line therapy begin with opioid rotation, as well as with low-cost and low-risk approaches such as lifestyle changes, consumption of fiber-rich food, stool softeners, and laxatives.

Advancing treatment options for chronic idiopathic constipation

INTRODUCTION

Chronic constipation is a global problem affecting all ages and associated with considerable morbidity and significant financial burden for society. Though formerly defined on the basis of a single symptom, infrequent defecation; constipation is now viewed as a syndrome encompassing several complaints such as difficulty with defecation, a sense of incomplete evacuation, hard stools, abdominal discomfort and bloating.

AREAS COVERED

The expanded concept of constipation has inevitably led to a significant change in outcomes in clinical trials, as well as in patient expectations from new therapeutic interventions. The past decades have also witnessed a proliferation in therapeutic targets for new agents. Foremost among these have been novel prokinetics, a new category, prosecretory agents and innovative approaches such as inhibitors of bile salt transport. In contrast, relatively few effective therapies exist for the management of those anorectal and pelvic floor problems that result in difficult defecation.

EXPERT OPINION

Though constipation is a common and often troublesome disorder, many of those affected can resolve their symptoms with relatively simple measures. For those with more resistant symptoms a number of novel, effective and safe options now exist. Those with defecatory difficulty (anismus, pelvic floor dysfunction) continue to represent a significant management challenge.

Current developments in pharmacological therapeutics for chronic constipation

Chronic constipation is a common gastrointestinal disease severely affecting the patient׳s quality of life. The traditional treatment of constipation is the use of laxatives. Recently, several new drugs including lubiprostone, linaclotide and prucalopride have been approved for treatment of chronic constipation. However, a significant unmet medical need still remains, particularly among those patients achieving poor results by current therapies. The 5-HT4 receptor modulators velusetrag and naronapride, the guanylate cyclase C agonist plecanatide and the ileal bile acid transporter inhibitor elobixibat are recognized as the most promising drugs under investigation. Herein, we give a comprehensive review on the pharmacological therapeutics for the treatment of chronic constipation, with the purpose of reflecting the drug development trends in this field.

Epidemiology and management of chronic constipation in elderly patients

Constipation is a common functional gastrointestinal disorder, with prevalence in the general population of approximately 20%. In the elderly population the incidence of constipation is higher compared to the younger population, with elderly females suffering more often from severe constipation. Treatment options for chronic constipation (CC) include stool softeners, fiber supplements, osmotic and stimulant laxatives, and the secretagogues lubiprostone and linaclotide. Understanding the underlying etiology of CC is necessary to determine the most appropriate therapeutic option. Therefore, it is important to distinguish from pelvic floor dysfunction (PFD), slow and normal transit constipation. Evaluation of a patient with CC includes basic blood work, rectal examination, and appropriate testing to evaluate for PFD and slow transit constipation when indicated. Pelvic floor rehabilitation or biofeedback is the treatment of choice for PFD, and its efficacy has been proven in clinical trials. Surgery is rarely indicated in CC and can only be considered in cases of slow transit constipation when PFD has been properly excluded. Other treatment options such as sacral nerve stimulation seem to be helpful in patients with urinary dysfunction. Botulinum toxin injection for PFD cannot be recommended at this time with the available evidence. CC in the elderly is common, and it has a significant impact on quality of life and the use of health care resources. In the elderly, it is imperative to identify the etiology of CC, and treatment should be based on the patient’s overall clinical status and capabilities.

Gastrointestinal Symptoms in Parkinson Disease: Clinical Aspects and Management

Although it is now generally recognized that the clinical spectrum of Parkinson disease (PD) is broader than its defining motor aspects, its various non-motor symptoms are often not routinely assessed in the clinical setting. As most of these symptoms are amenable to treatment, improved recognition would lead to more comprehensive management of the disease, and ultimately improve the quality of life for PD patients. In an attempt to increase the general awareness of physicians caring for these patients, this article focuses on the clinical manifestations and treatment of the gastrointestinal symptoms most commonly experienced by PD patients, as well as on the gastrointestinal side effects of antiparkinsonian treatments.

The management of gastrointestinal symptoms in Parkinson's disease

The involvement of the autonomic nervous system in Parkinson's disease causes many non-motor symptoms, among which gastrointestinal complaints are prominent. Drooling, dyspepsia, constipation, abdominal pain and fecal incontinence are frequently a source of patient distress. Dysphagia is recognized as causing both discomfort and increased risk of serious complications. Although a diagnosis can often be established based on the reports of patients and/or caregivers, and additional testing is seldom required, these diagnoses are clearly under recognized in clinical practice. These symptoms respond to the same treatment measures used in the general population, although certain drugs with a potential to increase parkinsonian symptoms should be avoided. Increased and early identification of these symptoms can result in a significant improvement in the quality of life of Parkinson's disease patients.

Colchicine is effective for short-term treatment of slow transit constipation: a double-blind placebo-controlled clinical trial

PURPOSE

Although colchicine has been tested in clinical trials for treatment of constipation, the index groups in those trials were composed of special patient groups with developmental neuromuscular defects or failed surgical management. The aim of this study is to investigate the efficacy of colchicine in patients with refractory slow transit constipation.

MATERIALS AND METHODS

Sixty patients with chief complaint of chronic constipation due to slow transit consented to be included in the double-blind placebo-controlled clinical trial. These patients were randomly divided into two groups (each containing 30 patients) to receive either colchicine, 1 mg QD, (group A) or placebo (group B) for 2 months. At the end of the study, Knowles-Eccersly-Scot symptom (KESS, a valid technique to assist in the diagnosis and evaluation of symptoms in constipation) scores were compared between the case and control groups.

RESULTS

The mean KESS score measured at the end of 2 months was 11.67 +/- 3.91 for colchicine and 18.66 +/- 3.72 for placebo group (p = 0.0001).

CONCLUSION

This trial shows that low-dose colchicine is effective in treatment of slow transit constipation.

Chronic constipation in the elderly

Chronic constipation is a common problem in the elderly, with a variety of causes, including pelvic floor dysfunction, medication effects, and numerous age-specific conditions. A stepwise diagnostic and therapeutic approach to patients with chronic constipation based on historical and physical examination features is recommended. Prudent use of fiber supplements and laxative agents may be helpful for many patients. Based on their capabilities, patients with pelvic floor dysfunction should be considered for pelvic floor rehabilitation (biofeedback), although efficacy in the elderly is uncertain. Clinical awareness and focused testing to identify the physiologic abnormalities underlying constipation, while being mindful of situations unique to the elderly, facilitate management, and improve patient outcomes.

Palliative care and pain: new strategies for managing opioid bowel dysfunction

Opioid analgesics are a cornerstone of pain therapy in the hospice and palliative care population. However, opioid-induced bowel dysfunction (OBD) is a commonly associated condition that frequently compromises the usefulness of these agents. Although its most common and debilitating symptom is constipation, the impact of OBD extends beyond constipation to encompass a myriad of gastrointestinal (GI) signs and symptoms, ranging from decreased gastric emptying and reflux to abdominal pain, cramping, bloating, nausea, and vomiting. Even after aggressive therapies to improve bowel function have been implemented, many patients continue to experience symptoms of OBD. To avoid these unwanted effects, some even choose to decrease or discontinue therapy with opioid analgesics, and experience inadequate pain control. The net result of OBD is a seriously negative impact on quality of life (QOL). For these reasons, it is important that palliative care practitioners have an adequate understanding of normal GI function and the underlying mechanisms responsible for OBD, the burden of OBD in the context of appropriate and effective pain management, and the benefits provided by effective pharmacotherapy. Several real-world cases are discussed to illustrate the application of optimal symptom management and the use of strategies that minimize the effects of OBD and improve patient QOL.

Dyssynergic defecation and biofeedback therapy

Constipation caused by dyssynergic defecation is common and affects up to one half of patients with this disorder. It is possible to diagnose this problem through history, prospective stool diaries, and anorectal physiologic tests. Randomized controlled trials have now established that biofeedback therapy is not only efficacious but superior to other modalities and that the symptom improvement is caused by a change in underlying pathophysiology. Development of user friendly approaches to biofeedback therapy and use of home biofeedback programs will significantly enhance the adoption of this treatment by gastroenterologists and colorectal surgeons.

[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.

Opioid-induced bowel dysfunction

Opioid-induced bowel dysfunction is a distressing condition that may persist indefinitely in the clinical setting. As we understand more about normal gastrointestinal (GI) physiology, we are also beginning to understand more fully how opioids cause bowel dysfunction. Current therapeutic interventions for opioid-induced bowel dysfunction can be burdensome and sometimes lack efficacy. Systemic opioid antagonists administered orally can induce laxation, but can unpredictably induce systemic or local GI tract withdrawal symptoms. Two new investigational agents, alvimopan and methylnaltrexone, are peripherally acting opioid antagonists that do not cross the blood-brain barrier. Studies to date show promise that these agents may relieve opioid-induced bowel dysfunction in a well-tolerated manner without reversing central analgesia.

Appropriate use of laxatives in the management of constipation

Chronic constipation is a frequent complaint in clinical practice. It is usually amenable to laxatives, which are available with and without prescription. An overemphasis on evidence-based analysis and aggressive marketing of newly developed laxative agents has tilted the recommendations toward more expensive, but not necessarily more effective, agents. This review addresses each of the four classes of laxatives and provides suggestions about their appropriate use in clinical practice.

Does postoperative misoprostol use induce intestinal motility? A prospective randomised double-blind trial

BACKGROUND

Misoprostol has been shown to increase colonic activity and decrease colonic transit time in chronic constipation patients.

AIMS

The aim of this prospective, randomised, double-blind study was to examine the effectiveness of rectally administered misoprostol on inducing intestinal motility after gynaecological surgery.

METHODS

Eighty women who underwent hysterectomy were divided randomly into three groups. Group A received misoprostol 200 microg rectally while group B received 400 microg rectal misoprostol after surgery before leaving the operating room. Patients in group C received no drugs. Bowel sounds in four quadrants were checked every hour and possible side-effects of misoprostol like nausea, vomiting, and distension were evaluated. The time interval between surgery and flatus pass and the need of analgesics were noted. Statistical analyses were done with Mann-Whitney U-test and chi2 tests where available.

RESULTS

The time between surgery and presence of bowel sounds in four quadrants were similar in all groups (2.7 +/- 1.6, 2.9 +/- 1.2, 2.8 +/- 1.3 h, for groups A, B, and C, respectively). No difference was observed in flatus pass time. The incidence of nausea was significantly increased in group B compared to controls (P < 0.01). Additional analgesic need was significantly higher in groups A and B when compared to controls (P < 0.05 and P < 0.01, for groups A and B, respectively).

CONCLUSION

Rectally administered misoprostol does not improve intestinal motility in the early postoperative period and thus, it is not effective in providing early oral food intake. On the contrary, it causes distention that requires additional analgesics and vomiting that naturally limits oral diet intake.

Cancer-related constipation

Cancer-related constipation is common and a significant detractor from patient quality of life. It has many possible causes and is still not well understood. Information is lacking on therapies for cancer-related constipation among current medications approved by the US Food and Drug Administration (FDA). Most agents have only been formally tested in comparison with placebo in chronic idiopathic constipation if at all. Few comparative studies of laxatives have been performed to establish superiority or synergy. As we understand more about the physiology of the gastrointestinal tract, new targeted therapies have become available. These include a selective chloride channel activator, lubiprostone, and a selective 5HT4 serotonin receptor agonist, tegaserod, both of which have been FDA approved for chronic idiopathic constipation. The role of these agents in cancer-related constipation remains to be seen. On the horizon are two investigational peripherally acting opioid receptor antagonists, alvimopan and methylnaltrexone. Preliminary results in cancer-related constipation suggest that these agents may be important additions to our treatment repertoire.

Constipation in Long-Term Care

Constipation is more common in older adults and accounts for increased physician office visits and hospital admissions. There is lack of agreement on the definition of constipation regarding what patients perceive as constipation and what physicians traditionally see as constipation. Constipation is related to multiple factors, and when left untreated or not properly treated, results in complications, such as impaction, even perforation and death. Laxative use increases with age and at times multiple agents are used to relieve symptoms of constipation. Currently the most commonly used laxative is stool softener but it lacks efficacy. From the review of literature, osmotic laxatives are effective in older adults and well tolerated. Psyllium, a bulk laxative, is also effective in the treatment of constipation, while there is limited evidence for stimulants, dioctyl sulfosuccinate, and other bulk laxatives such as calcium polycarbophil and methylcellulose. A new drug, lubiprostone, is a type 2-chloride channel activator and is shown to be effective, safe, and well tolerated in older adults treated for chronic constipation in studies up to a year. It appears to be particularly useful in persons who have recurrent fecal impaction and in those with severe chronic constipation. There is a need for a large-scale trial examining an appropriate cost-effective approach to the management of constipation in the nursing home.

Chronic constipation: advances in management

Only a relatively small percentage of clinically constipated patients seek medical attention and most can be managed satisfactorily with conservative measures. This review mainly addresses those patients who have refractory or difficult-to-manage functional constipation who are referred to gastrointestinal specialists. Areas of review include insights into pathophysiology, the utility of diagnostic testing and the author's opinions concerning available pharmacologic agents, the role of behavioural therapies and the indications for surgical interventions in this heterogeneous group of patients.

Constipation in the primary care setting: current concepts and misconceptions

Constipation is prevalent in Western societies and is a common illness in clinical practice. A broader clinical definition, which encompasses difficult and infrequent defecation, has aligned medical concepts with that of patients and the general population. Unfortunately, there are widespread misconceptions concerning the origins and management of constipation within both the lay and medical communities that influence recommendations by health care practitioners. This review highlights and seeks to correct some of these misconceptions and provide treatment guidelines for the practicing physician.

Pseudo-obstruction intestinale chronique

Chronic intestinal pseudo-obstruction (CIPO) is a disease characterized by episodes resembling mechanical obstruction in the absence of organic, systemic, or metabolic disorders. Pseudo-obstruction is an uncommon condition and can result from primary (40%) or secondary (60%) causes. The most common symptoms are nausea, vomiting, abdominal distension, abdominal pain and constipation or diarrhea. These symptoms are usually present many years before CIPO diagnosis. They can lead to severe electrolyte disorders and malnutrition. Principles for management of patients with CIPO are: to establish a correct clinical diagnosis in excluding mechanical obstruction; to perform a symptomatic and physiologic assessment of the gastrointestinal tract involved; to look for extra-intestinal manifestations, especially for myopathy and neuropathy; to discuss in some cases a surgery for full-thickness intestinal biopsies, and/or a neuromuscular biopsy in case of mitochondrial cytopathy suspicion. The management is primarily focused on symptom control and nutritional support to prevent weight loss and malnutrition. Treatment of CIPO includes prokinetic agents which may help to reduce gastrointestinal symptoms Courses of antibiotics may be needed in patients with symptoms suggestive of bacterial overgrowth. When necessary, enteral nutrition is preferred. In carefully selected patients, feeding jejunostomy with or without decompression gastrostomy may be tried. Long term parenteral nutrition should be reserved for patients who can not tolerate enteral nutrition. Intestinal transplantation can be discussed in selected patients.

Irritable bowel syndrome and chronic constipation: emerging drugs, devices, and surgical treatments

Irritable bowel syndrome (IBS) and chronic constipation (CC) are two of the most common functional disorders of the gut. CC and IBS are estimated to affect up to 20% and 27% of the North American population respectively. Although not life-threatening, CC and IBS can profoundly and negatively affect quality of life and are associated with a significant economic burden related to direct and indirect annual health-care costs. Possible etiologies for IBS and CC include alterations in visceral sensation and gastrointestinal motility. IBS may be caused by disturbances in brain-gut interactions affecting gastrointestinal motility and visceral sensitivity. Research efforts in CC have begun to identify abnormalities in myenteric neurons, alterations in neurotransmitters and their receptors, and incoordination of the muscles of the pelvic floor or anorectum. Both disorders may be influenced by genetic predisposition, environmental factors, and stress. In this article, the safety and efficacy of traditional and emerging therapies for CC and IBS are examined. In addition, their pathophysiology and symptoms are briefly reviewed.

Pathophysiology, diagnosis and current management of chronic constipation

Chronic constipation is prevalent in Western countries and is a complaint that is commonly seen in clinical practice. Only a relatively small percentage of constipated patients seek medical evaluation and most can be managed satisfactorily with first-line, conservative therapy. In patients with severe, refractory constipation, additional studies of colonic and anorectal function have clinical utility, as such patients are candidates for therapies not given to most constipated patients. This article reviews the modern principles and therapies used to manage chronic constipation of varying severities.

New and emerging treatments for irritable bowel syndrome and functional dyspepsia

The symptomatic management of irritable bowel syndrome (IBS) and functional dyspepsia, which often overlap, can be frustrating and difficult. Education and reassurance remain central for management although controlled trials are lacking. Psychological interventions may be useful in select patients but methodological inadequacies in clinical trials limit their interpretability. For symptom exacerbations, drug treatment is reasonable but no current treatment successfully targets the full symptom complex. Bulking agents are not of proven efficacy in IBS; they may improve constipation but worsen bloating and pain. Anticholinergics are of uncertain value in IBS. A meta-analysis of trials of smooth muscle relaxants for IBS has been reported to be positive but the quality of the trials included was poor. Antidepressants for IBS and functional dyspepsia appear to be efficacious based on the limited published evidence; both global symptoms and abdominal pain improve. Selective serotonin reuptake inhibitors (SSRIs) are of uncertain efficacy but anecdotally appear to be useful. Laxatives are not of proven efficacy in IBS. Loperamide improves diarrhea, but not abdominal pain in IBS. No drug is of proven efficacy for bloating. Acid suppression remains the mainstay of therapy for functional dyspepsia but the majority of patients do not have an adequate response. Promising drugs include new prokinetics for constipation-predominant IBS (e.g., tegaserod, a partial 5-HT4 agonist, prucalopride, a full 5-HT4 agonist, and dexloxiglumide, a cholecystokinin1 antagonist), agents for diarrhea-predominant IBS (e.g., 5-HT3 antagonists, alpha2 receptor agonists and corticotrophin receptor-1 antagonists), other visceral analgesics (e.g. tachykinin antagonists, opioid agonists) and in dyspepsia fundus relaxing agents (e.g., 5-HT1 agonists, tegaserod).

The treatment of chronic constipation in elderly people: an update

Constipation is a common problem in elderly persons, with prevalence ranging from 15% to 20% in the community-dwelling elderly population and up to 50% in some studies of nursing home residents. In these patients, constipation results from a combination of risk factors, such as reduced fibre and fluid intake, decreased physical activity resulting from chronic diseases and multiple medications. Despite the high prevalence of constipation, there is surprisingly little evidence available on which to base management decisions of this common condition. Increased fluid intake, regular physical activity and high fibre intake are usually proposed as first step nonpharmacological measures. However, adherence to these measures is limited and pharmacological treatment is frequently required. Data are too limited, especially in elderly persons, to formally recommend one class of laxatives over another or one agent over another within each class. However, bulk-forming and osmotic laxatives are usually recommended as first-line agents, even though data on their effectiveness are limited. The need to maintain good hydration is a limitation in the use of bulk-forming laxatives, in particular, in frail elderly patients. In these patients, polyethylene glycol, an osmotic agent, is an attractive alternative. In addition, it has been shown to relieve faecal impaction in frail patients with neurological disease. Its cost and potential danger in patients at high risk for aspiration is, however, a limitation. Stimulant laxatives are considered mainly as an intermittent treatment in patients who do not respond to bulk-forming or osmotic laxatives. Several promising compounds such as the new serotonin 5-HT4 receptor agonists (tegaserod, prucalopride) and neurotrophin-3 (NT3) have not been adequately tested in older individuals. They are not routinely used and their role in the management of constipation in these patients will be more precisely defined in the future. Other treatment options are available (acupuncture, biofeedback, botulinum toxin and surgery), but experience with these interventions in elderly patients is limited and their indications in this population remain to be clarified. Management of constipation in elderly persons depends largely on experience and beliefs. Several new compounds seem promising but will need to be specifically tested in this population before being recommended.

Treatment options for primary constipation

Patients suffering from primary constipation often show symptom improvement with increased intake of fiber. Bulk laxatives are a core component of treatment if dietary fiber is unsuccessful in alleviating symptoms. Although there are a number of commercial laxative preparations available, only polyethylene glycol (PEG), an osmotic laxative, should be used on a daily basis. For the elderly, saline laxatives may be used on a regular basis, provided there are no cardiac or renal comorbid contraindications. Tegaserod, a 5-HT(4) partial receptor agonist, is approved for the treatment of constipation in female patients. The appropriate role of biofeedback remains to be determined. Surgery should be reserved for patients with slow transit constipation refractory to medical therapy. Patients being considered for surgery should be evaluated at institutions with substantial expertise in the investigation and management of this population.

Constipation: evaluation and treatment

Constipation is a common clinical problem that comprises a constellation of symptoms that include excessive straining, hard stools, feeling of incomplete evacuation, use of digital maneuvers, or infrequent defecation. Although many conditions, such as metabolic problems, fiber deficiency, anorectal problems, and drugs, can cause constipation, when excluded functional constipation consists of two subtypes: slow-transit constipation and dyssynergic defecation. Some patients with irritable bowel syndrome may exhibit features of both types of constipation. The Rome criteria for functional constipation together with modifications proposed here for dyssynergic defecation may serve as useful guidelines for making a diagnosis. Recent advances in technology, together with a better understanding of the underlying mechanisms, have led to real progress in the diagnosis of this condition. Management options are limited, however, and evidence to support these treatments is only modest. The treatment is primarily medical; surgical options should be reserved for refractory disease and after careful diagnostic work-up. Although laxatives remain the mainstay of therapy, prokinetics that are colon-selective are optimal for treating patients with slow-transit constipation, but they are not yet available for clinical use. Recent controlled trials, however, are promising. Biofeedback therapy is the preferred treatment for patients with dyssynergia, but is not widely available. In the near future, user-friendly biofeedback programs including home therapy may facilitate wider use of these methods for patients with dyssynergic defecation.

Pharmacologic therapy for the irritable bowel syndrome

The management of the irritable bowel syndrome (IBS) remains unsatisfactory. For abdominal pain, antispasmodics are, at best, of only modest efficacy. Tricyclic antidepressants in low dose are useful (with the number needed to treat being three), but side effects and patient concerns regarding use of a centrally acting agent for depression remain limitations. Selective serotonin reuptake inhibitors are of uncertain efficacy in IBS. Opioid agonists, especially loperamide, are useful for diarrhea but not for pain in IBS; rebound constipation also remains a problem. Bile salt sequestering agents are not of established value in IBS but seem to be useful clinically in a small group of IBS patients with diarrhea. Aloestron, a 5HT(3) antagonist, should be reserved, if available, for women with severe diarrhea predominant IBS who have failed to respond to conventional therapy, and started at a low dose. Fiber and bulking agents may help constipation in some trials, but the evidence that they are efficacious in IBS is equivocal; they are frequently prescribed as first-line drugs for IBS regardless of the primary bowel disturbance but often increase bloating, gas, and pain. Laxatives are not of established value in IBS but are often taken by patients with constipation predominant IBS. Tegaserod, a partial 5HT(4) agonist, is now available in the United States and other countries for use in women with IBS whose primary bowel symptom is constipation; its efficacy in men and in those with alternating bowel habits is unknown. Probiotics are of uncertain efficacy. Chinese herbal medicine data are insufficient. Other new drugs in development include the cholecystokinin antagonists and novel visceral analgesics. Both current and potential therapies for IBS are reviewed in this article.

Gastrointestinal dysfunction in Parkinson's disease

There is growing recognition that gastrointestinal dysfunction is common in Parkinson's disease (PD). Virtually all parts of the gastrointestinal tract can be affected, in some cases early in the disease course. Weight loss is common but poorly understood in people with PD. Dysphagia can result from dysfunction at the mouth, pharynx, and oesophagus and may predispose individuals to aspiration (accidental inhalation of food or liquid). Gastroparesis can produce various symptoms in patients with PD and may cause erratic absorption of drugs given to treat the disorder. Bowel dysfunction can consist of both slowed colonic transit with consequent reduced bowel-movement frequency, and difficulty with the act of defecation itself with excessive straining and incomplete emptying. Recognition of these gastrointestinal complications can lead to earlier and potentially more effective therapeutic intervention.

Treatment Options for Refractory Childhood Constipation

Constipation in children is very common. Childhood constipation responds successfully to medical therapies, behavioral modifications, or a combination of both in approximately 70% of children within 2 years of diagnosis. Persistence of constipation is associated with fecal incontinence, recurrent fecal impactions, and significant emotional problems. Refractory constipation that interferes with both the child's function and the family's life requires extensive evaluations in order to uncover its cause and devise appropriate therapeutic strategies. Children with persistent constipation can be divided into three broad categories: 1) those who have functional constipation, 2) those affected by enteric neuromuscular disorders, and 3) those whose constipation is associated with neurologic handicaps. Treatment options vary widely. The majority of patients require more aggressive medical and more intense behavioral interventions. Others benefit from novel approaches, including surgical intervention.

Slow Transit Constipation

The diagnosis of slow transit functional constipation is based upon diagnostic testing of patients with idiopathic constipation who responded poorly to conservative measures such as fiber supplements, fluids, and stimulant laxatives. These tests include barium enema or colonoscopy, colonic transit of radio-opaque markers, anorectal manometry, and expulsion of a water-filled balloon. Plain abdominal films can identify megacolon, which can be further characterized by barium or gastrografin studies. Colonic transit of radio-opaque markers identifies patients with slow transit with stasis of markers in the proximal colon. However, anorectal function should be characterized to exclude outlet dysfunction, which may coexist with colonic inertia. Because slow colonic transit is defined by studies during which patients consume a high-fiber diet, fiber supplements are generally not effective, nor are osmotic laxatives that consist of unabsorbed sugars. Stimulant laxatives are considered first-line therapy, although studies often show a diminished colonic motor response to such agents. There is no evidence to suggest that chronic use of such laxatives is harmful if they are used two to three times per week. Polyethylene glycol with or without electrolytes may be useful in a minority of patients, often combined with misoprostol. I prefer to start with misoprostol 200 mg every other morning and increase to tolerance or efficacy. I see no advantage in prescribing misoprostol on a TID or QID basis or even daily because it increases cramping unnecessarily. This drug is not acceptable in young women who wish to become pregnant. An alternative may be colchicine, which is reported to be effective when given as 0.6 mg TID. Long-term efficacy has not been studied. Finally, biofeedback is a risk-free approach that has been reported as effective in approximately 60% of patients with slow transit constipation in the absence of outlet dysfunction. Although difficult to understand conceptually, it is worth attempting and certainly so in patients with associated pelvic floor dyssynergia. Subtotal colectomy with ileorectal anastomosis is often effective in those patients with colonic inertia, normal anorectal function, and lack of evidence of generalized intestinal dysmotility. However, morbidity is significant both early and late in the disease process and must be balanced against current disability. Ileostomy is preferred in the presence of anorectal dysfunction or with associated impairment of continence mechanisms. Similar considerations apply to the patient with disabling functional megacolon. An alternative approach is ileostomy with disconnection of the colon, which is more acceptable to some patients who may hope for future reconnection if recovery occurs. An additional alternative approach for patients with colonic inertia or megacolon who are not good surgical risks is tube cecostomy (or in children, use of the appendix as a conduit to the cecum). This permits either decompression (in megacolon) or antegrade enemas (in colonic inertia). Our surgeons are not enthusiastic about this approach, and I have little experience with it. In general, the use of partial resections of the colon should be discouraged, because marker studies do not define pathophysiology in patients with slow transit constipation.

Serotoninergic neuroenteric modulators

Irritable bowel syndrome (IBS) is common and can be disabling. Several drugs that modulate serotonin (5HT) and other neurotransmitters in the gut (neuroenteric modulators) have either become available or are in development, but progress has been slowed by toxicity. Blockade of 5HT(3) receptors slows colonic transit, increases fluid absorption and increases left colon compliance. Alosetron, a potent 5HT(3) receptor antagonist, has, in women but not in men, a clinically significant but modest therapeutic gain over placebo in the relief of abdominal pain and discomfort and bowel-habit disturbance (but not bloating) in diarrhoea-predominant IBS. However, the drug unexpectedly was associated with ischaemic colitis and, very rarely, severe constipation-induced complications, and alosetron has been withdrawn. Cilansetron may have similar efficacy in men and women. 5HT(4) receptor stimulation results in accelerated colonic transit, and tegaserod, a partial 5HT(4) receptor agonist, has modest but clinically significant advantage over placebo in constipation-predominant IBS; the benefit seems to be confined to females. Long-term published data are lacking and safety concerns have been raised. Prucalopride, a full 5HT(4) agonist that has been promising in idiopathic chronic constipation, may also be limited by toxicity. Other 5HT receptor antagonists and agonists are under development for IBS. However, for modulators of single receptors to achieve a substantial therapeutic gain, and to do so safely, drug targets based on the pathophysiology of IBS need to be better defined.

Review article: the therapy of constipation

Constipation is a common symptom that may be idiopathic or due to various identifiable disease processes. Laxatives are agents that add bulk to intestinal contents, that retain water within the bowel lumen by virtue of osmotic effects, or that stimulate intestinal secretion or motility, thereby increasing the frequency and ease of defecation. Drugs which improve constipation by stimulating gastrointestinal motility by direct actions on the enteric nervous system are under development. Other modalities used to treat constipation include biofeedback and surgery. Laxatives and lavage solutions are also used for colon preparation and evacuation of the bowels after toxic ingestions.

Constipation and fecal incontinence in the elderly

Although constipation and fecal incontinence are common symptoms in the elderly, relatively little research has been done to differentiate physiologic changes in rectoanal function resulting from aging and pathologic changes resulting from diseases occurring as patients age. Certain physiologic changes occur in many older patients and may predispose them to the development of constipation or fecal incontinence. These symptoms need the same thoughtful evaluation and management in the elderly as in younger patients. Results of therapy often can be good, leading to alleviation of suffering and the ability to lead a fuller life.

Association of bowel movement frequency and use of laxatives with the occurrence of symptomatic gallstone disease in a prospective study of women

OBJECTIVES

The authors prospectively examined the association between bowel movement frequency (used as a proxy for intestinal transit), laxative use, and the risk of symptomatic gallstone disease.

METHODS

A total of 79,829 women, aged 36-61 yr, without a history of symptomatic gallstone disease and free of cancer, responded to a mailed questionnaire in 1982 that assessed bowel movement frequency and use of laxatives. Between 1984 and 1996, 4,443 incident cases of symptomatic gallstone disease were documented. Relative risks (RRs) of symptomatic gallstone disease and 95% confidence intervals (CIs) were calculated using logistic regression.

RESULTS

After controlling for age and established risk factors, the multivariate RRs were, compared to women with daily bowel movements, 0.97 (95% CI 0.86-1.08) for women with bowel movements every third day or less, and 1.00 (95% CI 0.91-11.1) for women with bowel movement more than once daily. No trend was evident. As compared to women who never used laxatives in 1982, a significant modest inverse association was seen for monthly laxative use, with a multivariate RR of 0.84 (95% CI 0.72-0.98), and weekly to daily laxative use was associated with a RR of 0.88 (95% CI 0.78-1.02).

CONCLUSIONS

These findings do not support an association between infrequent bowel movements and risk of symptomatic gallstone disease in women, and indicate that simple questions directed at bowel movement frequency are unlikely to enhance our ability to predict risk of symptomatic gallstone disease. The slightly inverse association between use of laxatives and risk of symptomatic gallstone disease may be due to a mechanism that is not related to bowel movement frequency.

Misoprostol therapeutics revisited

Misoprostol, a prostaglandin E1 analog, is a racemate of four stereoisomers. On administration it rapidly de-esterifies to its active form, misoprostolic acid. Misoprostolic acid is 85% albumin bound and has a half-life of approximately 30 minutes. It is excreted in urine as inactive metabolites. No significant drug interactions have been reported. Besides its gastrointestinal protective and uterotonic activities, misoprostol regulates various immunologic cascades. It inhibits platelet-activating factor and leukocyte adherence, and modulates adhesion molecule expression. It protects against gut irradiation injury, experimental gastric cancer, enteropathy, and constipation. It improves nutrient absorption in cystic fibrosis. Misoprostol has utility in acetaminophen and ethanol hepatotoxicity, hepatitis, and fibrosis. It is effective in asthmatics and aspirin-sensitive asthmatic and allergic patients. It lowers cholesterol and severity of peripheral vascular diseases, prolongs survival of cardiac and kidney transplantation, synergizes cyclosporine, and protects against cyclosporine-induced renal damage. It works against drug-induced renal damage, interstitial cystitis, lupus nephritis, and hepatorenal syndrome. It is useful in periodontal disease and dental repair. Misoprostol enhances glycosoaminoglycan synthesis in cartilage after injury. It prevents ultraviolet-induced cataracts and reduces intraocular pressure in glaucoma and ocular hypertension. It synergizes antiinflammatory and analgesic effects of diclofenac or colchicine and has been administered to treat trigeminal neuralgic pain. It reduces chemotherapy-induced hair loss and recovery time from burn injury, and is effective in treating sepsis, multiple sclerosis, and pancreatitis.

Approach to patients with refractory constipation

Constipation is a very frequent problem, particularly in elderly patients. Constipation is a common reason for patients to seek medical advice, and it accounts for a large number of different prescription and over-the-counter medications. In many cases, no definite cause can be found. Most patients respond to conservative therapy with increased fiber and fluid intake alone. Patients with constipation that is more difficult to control or with alarm symptoms (eg, blood in stool, sudden onset, weight loss, or decreasing stool caliber) warrant further investigation. A variety of medical, behavioral, and surgical therapies can be employed to help these more refractory patients.

Functional gut disorders: from motility to sensitivity disorders. A review of current and investigational drugs for their management

Functional gut disorders include several clinical entities defined on the basis of symptom patterns (e.g., functional dyspepsia, irritable bowel syndrome, functional abdominal pain, functional abdominal bloating), for which there is no established pathophysiological mechanism. Because there is no well-defined pathophysiological target, treatment should be aimed at symptom improvement. Prokinetics and antispasmodics have been widely used in the treatment of functional gut disorders on the assumption that disordered motility is the underlying cause of symptoms, and symptom improvement is indeed achievable with these compounds in some, but not all, patients with features of hypo- or hypermotility, respectively. In the first part of this review, we cover the basic pharmacology and discuss the rationale for the clinical use of prokinetics and antispasmodics. On the other hand, in the past few years, the explosive growth in the research focusing on visceral sensitivity and visceral reflexes has suggested that at least some patients with functional gut disorders have altered visceral perception. Thus, the second part of the review covers these developments and focuses on studies addressing the issue of drugs modulating visceral sensitivity.