Functional bowel disorders

Chronic constipation: a survey of the patient perspective

BACKGROUND

Constipation is a common, often chronic, gastrointestinal motility disorder characterized by such symptoms as straining, hard stool, and infrequent defecation. Published literature is limited regarding symptom prevalence, healthcare-seeking behaviour, and patient satisfaction with traditional therapies for chronic constipation.

AIM

To assess the prevalence of chronic constipation among a random sample of Americans, to identify the frequency, severity and bothersomeness of their symptoms, and to assess satisfaction levels with traditional treatments.

METHODS

All members (N = 37,004) of the Knowledge Networks Panel, representative of the US population, participated in a web-based survey. Eligibility was established using a six-question screener.

RESULTS

Of the 24,090 panellists consenting to participate, 557 met eligibility requirements and took the 45-question survey. The most prevalent symptom was straining (79%). Hard stool and straining were the top two severe symptoms, and bloating, straining and hard stool were the top three bothersome symptoms. Symptoms affected quality of life of more than half (52%) the respondents. Among those who worked or went to school, 12% experienced reduced productivity and a mean of 2.4 days of absence in the month before the survey. Most respondents had used (96%) or were using (72%) constipation relief therapy; however, nearly half (47%) were not completely satisfied, mainly because of efficacy (82%) and safety (16%) concerns.

CONCLUSIONS

Chronic constipation is common. Individual symptoms are often severe and bothersome, and many patients are dissatisfied with traditional treatment options, primarily because of lack of efficacy.

The management of constipation in hospital inpatients

This article reviews the causes of constipation in hospital and how it can be prevented with simple measures. A review of laxatives available on hospital words is provided for the reader and recommendations are made.

New insights into the pathogenesis and pathophysiology of irritable bowel syndrome

The pathogenesis and pathophysiology of irritable bowel syndrome is complex and still incompletely known. Potential pathogenetic factors include genes, infectious events, psychological symptoms and other loosely defined environmental factors. Both alterations at the central and peripheral level are thought to contribute to the symptoms of irritable bowel syndrome, including psychosocial factors, abnormal gastrointestinal motility and secretion, and visceral hypersensitivity. Today irritable bowel syndrome is viewed upon as a disorder of dysregulation of the so-called brain-gut axis, involving abnormal function in the enteric, autonomic and/or central nervous systems, with peripheral abnormalities probably dominating in some patients and disturbed central processing of signals from the periphery in others. Lines of evidence also suggest that inflammation within the gastrointestinal tract may be of great importance in at least subgroups of irritable bowel syndrome patients. To conclude, a complex picture of the pathogenesis and pathophysiology of irritable bowel syndrome is emerging, with interactions between several different alterations resulting in the divergent symptom pattern in these patients.

Efficacy of tegaserod for functional constipation in Chinese subjects: a randomized double-blind controlled trial in a single centre

BACKGROUND

Tegaserod has been shown to be effective in chronic constipation in Western population. Aim We investigated if tegaserod is equally effective in Chinese population.

MATERIALS AND METHODS

Two hundred and fifty patients were randomized to a double-blinded 8-week treatment of tegaserod 6 mg b.d. or placebo. Response during weeks 1-4 was defined as an increase in complete spontaneous bowel motion >/=1/week. Secondary efficacy included response during weeks 1-8, individual symptoms and scores, quality of life and global assessment of bowel habits and constipation.

RESULTS

One hundred and nine patients from the treatment group and 107 from the placebo group completed the 8-week treatment. Responder rates was 47.7% vs. 29% for the treatment and placebo groups (P = 0.005). The sustained complete spontaneous bowel motion rate was 29.4% vs. 15.7% in the two groups (P = 0.016). The response rates were higher than that reported previously in the Caucasian studies. There was improvement in the scores for stool form scale, bothersomeness of constipation, abdominal distension/bloating and satisfaction of bowel habit (P < 0.05). The mental score was higher in the treatment group (46.8 +/- 9 vs. 43.6 +/- 10, P = 0.01).

CONCLUSIONS

Tegaserod is effective in relieving chronic constipation in Chinese population. The efficacy observed may be higher than that in Western population.

A randomized, double-blind, placebo-controlled trial assessing the efficacy and safety of tegaserod in patients from China with chronic constipation

AIM

To evaluate the efficacy and safety of tegaserod, 6 mg twice daily (b.i.d.), in men and women with chronic constipation (CC) from China.

METHODS

This was a multicenter, double-blind, placebo-controlled study. Following a 2-wk treatment-free baseline period, patients were randomized to receive either tegaserod (6 mg b.i.d.) or placebo (b.i.d.) for 4 wk. An analysis of covariance with repeated measures was used to determine the overall effect of treatment for the primary efficacy variable; the change from baseline in the number of complete spontaneous bowel movements (CSBMs) during the 4-wk treatment period. Secondary efficacy endpoints included other measures of response in terms of CSBMs, and patients' daily and weekly assessment of bowel habits. Safety was also assessed, based on the incidence and severity of adverse events (AEs).

RESULTS

A total of 607 patients were randomized to receive either tegaserod (n = 304) or placebo (n = 303). Tegaserod treatment resulted in a rapid and significant increase from baseline in the adjusted mean number of CSBMs per week over wk 1-4 compared with placebo (1.39 vs 0.91, P = 0.0002). A statistically significant difference in favor of tegaserod was also observed for a mean increase > or = 1 CSBM/wk over wk 1-4 (47.7% vs 35.0%, tegaserod vs placebo, respectively, P = 0.0018) and for the absolute number of > or = 3 CSBMs/wk over wk 1-4 (25.0% vs 14.5%, tegaserod vs placebo, respectively, P = 0.0021). Improvements in other symptoms of CC were also seen in the tegaserod group, including improved stool form and reduced straining. In addition, more patients in the tegaserod group reported satisfactory relief from their constipation symptoms. The frequency and severity of AEs was comparable between tegaserod and placebo groups, with the exception of a greater incidence of diarrhea in patients receiving tegaserod (3.6%) compared with placebo (1.7%).

CONCLUSION

Tegaserod treatment improved multiple symptoms of CC and was associated with a favorable safety profile.

Mechanisms of Disease: genetics of functional gastrointestinal disorders—searching the genes that matter

There is evidence to suggest that genetic factors contribute to the manifestation of functional gastrointestinal disorders (FGID). As such, it is important to note that FGID are heterogeneous; they have quite different clinical features and (probably) different underlying pathophysiologic mechanisms. Evidence from family and twin studies indicates that there is clustering of FGID in families and increased concordance in monozygotic compared with dizygotic twins. The clinical features of FGID implicate polymorphisms in the genes that encode adrenergic, opioidergic or serotonergic receptors, as well as in the G-protein beta3 subunit (GNB3) gene and serotonin-transporter genes, in their manifestations. As mediators or regulators of mucosal inflammation can trigger events that ultimately result in manifestations of FGID, polymorphisms in genes that encode proteins with immunomodulatory and/or neuromodulatory features (e.g. OPRM1, IL4, IL4R, TNF) might also have a role in the manifestation of FGID. A two-step model for the role of genetic factors in the manifestation of functional gastrointestinal pain can, therefore, be proposed. In the presence of specific hereditary factors, environmental factors that do not usually cause long-term functional alterations are linked to the manifestation of symptoms.

Change over time of bowel habit in irritable bowel syndrome: a prospective, observational, 1-year follow-up study (RITMO study)

BACKGROUND

Evolution of bowel habit in irritable bowel syndrome (IBS) is not well known.

AIM

To evaluate the change over time of bowel habit in IBS patients followed-up during 1 year.

METHODS

Five hundred and seventeen patients with IBS were prospectively included in an observational study with five evaluations over a 1-year period. Symptoms were recorded daily in diary cards during four 4-week periods along the study. Bristol Stool Scale (BSS) was used to define bowel habit.

RESULTS

Four-hundred patients completed the study. Rome II showed low-moderate agreement (42%) with BSS to define bowel habit. Frequency of constipation and diarrhoea showed little changes throughout the study. Over 50% of the patients had the same bowel habit when each diary was compared with the next one. A third of patients maintained the same habit throughout the study. Most changes occurred from/to mixed or unsubtyped IBS. Only 14% of cases changed from constipation to diarrhoea or vice versa. This change was associated to female gender (OR: 2.65).

CONCLUSIONS

The frequency of constipation and diarrhoea remains relatively stable over time. Changes in IBS subtypes are common, but changes between constipation and diarrhoea are rare. Alternating IBS is more frequent in women.

Differential diagnosis between functional and organic intestinal disorders: Is there a role for non-invasive tests?

Abdominal pain and bowel habits alterations are common symptoms in the general population. The investigation to differentiate organic from functional bowel disorders represents a considerable burden both for patients and public health service. The selection of patients who should undergo endoscopic and/or radiological procedures is one of the key points of the diagnostic process, which should avoid the abuse of invasive and expensive tests as well as the underestimation of potentially harmful diseases. Over the coming years, clinicians and researchers will be challenged to develop strategies to increase the patient’s compliance and to reduce the economic and social costs of the intestinal diseases.

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.

Role of corticotropin-releasing hormone in irritable bowel syndrome and intestinal inflammation

Corticotropin-releasing hormone (CRH) is a major mediator of stress response in the brain-gut axis. Irritable bowel syndrome (IBS) is presumed to be a disorder of the brain-gut link associated with exaggerated response to stress. We first showed that peripheral administration of CRH aggravated visceral sensorimotor function as well as adrenocorticotropic hormone (ACTH) response in IBS patients. We then administered alpha-helical CRH (alphahCRH), a non-selective CRH receptor antagonist among IBS patients. Electrical stimulation of the rectum induced significantly higher motility indices of the colon in IBS patients than in the controls. This response was significantly suppressed in IBS patients but not in the controls after administration of alphahCRH. Administration of alphahCRH induced a significant increase in the barostat bag volume of the controls but not in that of IBS patients. alphahCRH significantly reduced the ordinate scale of abdominal pain and anxiety evoked by electrical stimulation in IBS patients. Plasma ACTH and serum cortisol were generally not suppressed by alphahCRH. Last, administration of CRH1-receptor (CRH-R1) specific antagonist blocked colorectal distention-induced sensitization of the visceral perception in rats. Moreover, pretreatment with CRH-R1 antagonist blocked colorectal distention-induced anxiety, which was measured with elevated plus-maze, in rats. Evidence supporting the concept that peripheral CRH and CRH-R1 play important roles in brain-gut sensitization is increasing. Several studies have identified immunoreactive CRH and urocortin as well as CRH-R1 and CRH-R2 mRNAs in human colonic mucosa. In addition, reverse transcription-polymerase chain reaction has revealed the expression of CRH-R1 mRNA in both the myenteric and submucosal plexus in the guinea pig. Application of CRH has been shown to evoke depolarizing responses associated with elevated excitability in both myenteric and submucosal neurons. On the other hand, peripheral injection of CRH has been reported to induce discrete effects on colonic secretory and motor function, and permeability. There are functional differences between CRH-R1 and CRH-R2. For instance, activation of CRH-R1 causes a proinflammatory response, whereas stimulation of CRH-R2 provokes anti-inflammatory changes. In addition, there is evidence of the contrasting roles of CRH-R1 and CRH-R2 in visceral nociception. While CRH-R1 is involved in the pro-nociceptive effects of visceral pain, CRH-R2 mediates an anti-nociceptive response. These findings suggest the major role of CRH in stress-related pathophysiology of IBS and possibly in inflammation of the intestinal mucosa.

Almost all irritable bowel syndromes are post-infectious and respond to probiotics: consensus issues

Several reports have described post-infectious irritable bowel syndrome (Pi-IBS), while many animal and human studies have shown the presence of increased infiltration of inflammatory cells and hyperplasia of enterochromaffin cells in the intestinal mucosa after acute gastroenteritis. The potential value of probiotic bacteria in restoring normal gut function has been demonstrated by animal models of Pi-IBS. In humans, Pi-IBS can be prevented utilizing probiotics to reduce the duration of acute gastroenteritis, despite the variable efficacy shown in randomized control trials evaluating unspecified IBS. Here, advances in the pathophysiology supporting the post-infectious hypothesis are considered. In addition, the current role of probiotics in the management of Pi-IBS is discussed.

The corner of the coloproctologist: what to ask to radiologist

Defecation disorders, fecal incontinence, often associated to urinary and genital dysfunction, represent symptoms of a large number of functional and structural alterations of pelvic floor. They can be evaluated by functional and morphologic tests. A perfect anatomic and functional knowledge of the anorectum and pelvic floor is indispensable for a correct diagnostic and therapeutic path. Incontinence due to sphincter lesions can be diagnosed only by imaging techniques. In defecation disorders the issue is complex because functional and anatomic alterations can coexist. The radiological diagnosis of dyssynergic defecation is a diagnosis of confidence that enhances its value when manometric and electromyographic evidence of pelvic dyssynergia are detected. When anatomical alterations are detected the aim is to understand their physiopathology, to make a more precise diagnosis and treatment, and to minimize the errors of an inappropriate therapy. Our attention is focused on the information provided by imaging techniques about anorectum and pelvic floor abnormalities for optimal therapeutic planning.

Role of motility in chronic diarrhoea

Patients complaining of 'chronic diarrhoea' usually mean the passage of loose, urgent stools. Chronic diarrhoea is a feature of malabsorption; it may also be seen in the 'dumping syndrome' which follows gastric surgery, small intestinal bacterial overgrowth, bile salt malabsorption and in malabsorption of simple sugars including most commonly lactose, fructose and sorbitol. Excessively rapid entry of chyme into the small or large intestine generates propulsive motor patterns leading to accelerated transit. Inflammation is associated with decreased normal mixing motor patterns but increased propulsive motility including high amplitude propagated contractions (HAPCs). Evidence for abnormal small intestinal motility in the diarrhoea associated with irritable bowel syndrome (IBS) is conflicting and any difference appears small. Increased colonic HAPCs with increased propulsion is seen in IBS with diarrhoea (IBS-D). Stress-induced colonic motility is increased in IBS-D with hyper-responsiveness to corticotrophin releasing factor (CRF). Long-lasting increases in mucosal serotonin availability may contribute to the chronic diarrhoea seen in IBS-D and coeliac disease. Treatments for abnormal motility in chronic diarrhoea include those designed to correct specific underlying abnormalities including octreotide, antibiotics, colestyramine, specific food avoidance and anti-inflammatory agents. There are also treatments aimed primarily at altering motility directly including opiates, 5HT3 receptor antagonists and amitriptyline.

5-HT in the enteric nervous system: gut function and neuropharmacology

In recent times, the perception of functional gastrointestinal disorders such as irritable bowel syndrome (IBS) has shifted fundamentally. Such disorders are now thought of as serious diseases characterized by perturbations in the neuronal regulation of gastrointestinal function. The concept of visceral hypersensitivity, the characterization of neuronal networks in the 'brain-gut axis' and the identification of several novel 5-HT-mediated mechanisms have contributed to this shift. Here, we review how some of the more promising of these new mechanisms (e.g. those involving 5-HT transporters and the 5-HT(2B), 5-HT(7) and putative 5-HT(1p) receptors) might lead to a range of second-generation therapies that could revolutionize the treatment of functional gastrointestinal disorders, particularly IBS.

Biofeedback therapy for dyssynergic defecation

Dyssynergic defecation is one of the most common forms of functional constipation both in children and adults; it is defined by incomplete evacuation of fecal material from the rectum due to paradoxical contraction or failure to relax pelvic floor muscles when straining to defecate. This is believed to be a behavioral disorder because there are no associated morphological or neurological abnormalities, and consequently biofeedback training has been recommended for treatment. Biofeedback involves the use of pressure measurements or averaged electromyographic activity within the anal canal to teach patients how to relax pelvic floor muscles when straining to defecate. This is often combined with teaching the patient more appropriate techniques for straining (increasing intra-abdominal pressure) and having the patient practice defecating a water filled balloon. In adults, randomized controlled trials show that this form of biofeedback is more effective than laxatives, general muscle relaxation exercises (described as sham biofeedback), and drugs to relax skeletal muscles. Moreover, its effectiveness is specific to patients who have dyssynergic defecation and not slow transit constipation. However, in children, no clear superiority for biofeedback compared to laxatives has been demonstrated. Based on three randomized controlled studies in the last two years, biofeedback appears to be the preferred treatment for dyssynergic defecation in adults.

Irritable Bowel Syndrome: A Practical Review

The epidemiology and current understanding of the pathophysiology of irritable bowel syndrome is reviewed, beginning with a historical perspective. The roles of genetics, environment, allergy, infection and inflammation, bacterial overgrowth, hormones and motility abnormalities are discussed. Using the current evidence-based literature, the practical approach of diagnosis and treatment is outlined, including traditional modalities and newer therapeutic agents such as serotonin modulators.

Treating chronic constipation : How should we interpret the recommendations?

Chronic constipation is a multisymptom gastrointestinal motility disorder that negatively impacts the lives of those affected. New recommendations on diagnosing and treating this condition have recently been published. This review aims to assist clinicians in applying these recommendations in clinical practice. Although lifestyle interventions and bulking agents help some patients with constipation, data are lacking to support their efficacy in those with chronic constipation. If empirical treatment of patients with chronic constipation fails, osmotic laxatives (e.g. lactulose and polyethylene glycol), a serotonin (5-HT4) receptor agonist (e.g. tegaserod) or a chloride channel activator (e.g. lubiprostone) can be considered. Osmotic laxatives, though effective at increasing stool frequency, are often associated with adverse effects such as bloating and diarrhoea and typically do not effectively relieve the multiple symptoms of chronic constipation. Use of tegaserod and the recently approved lubiprostone is supported by high-quality evidence, and these agents have acceptable safety profiles in patients with chronic constipation. Recent advances in the definition of chronic constipation and in its pharmacological management have led to refinements in identifying the appropriate treatment needs of patients with this condition. It is hoped that these advancements will help clinicians select effective medical regimens for patients with chronic constipation.