Functional bowel disorders

Lubiprostone: a novel treatment for chronic constipation

Chronic constipation is highly prevalent, reduces patients' quality of life, and imposes a significant health care burden on society. Lifestyle modifications and over-the-counter agents improve symptoms of constipation in some patients, however many patients have persistent symptoms and require the use of prescription medications. Three prescription medications are currently Food and Drug Administration (FDA) approved and available for the treatment of chronic constipation in adults. This review will focus on lubiprostone, the newest medication available for the treatment of chronic constipation. Lubiprostone is a bicyclic fatty acid metabolite analogue ofprostaglandin E1. It activates specific chloride channels in the gastrointestinal tract to stimulate intestinal fluid secretion, increase gastrointestinal transit, and improve symptoms of constipation. This article will provide a brief overview on chloride channel function in the gastrointestinal tract, describe the structure, function, and pharmacokinetics of lubiprostone, and discuss the safety and efficacy of this new medication.

Review article: abdominal bloating and distension in functional gastrointestinal disorders--epidemiology and exploration of possible mechanisms

BACKGROUND

A sensation of abdominal bloating, sometimes accompanied by an increase in girth (distension), is one of the most common and most intrusive features of functional bowel disorders.

AIM

To conduct a systematic, evidence-based review of the epidemiology and pathophysiology of abdominal bloating and its relationship to distension.

METHODS

The terms bloating, distension, functional bowel, irritable bowel syndrome, constipation and diarrhoea were searched on MEDLINE up to 2006. References from selected articles and relevant abstracts were also included.

RESULTS

Approximately 50% of irritable bowel syndrome patients with bloating also experience an increase in abdominal girth and this is more pronounced with constipation than diarrhoea. Bloating appears to be more frequently associated with visceral hypersensitivity, whereas distension is more often related to hyposensitivity and delayed transit. Although there is little evidence for excessive gas as a cause of bloating, gas infusion studies suggest that handling of gas may be impaired in irritable bowel syndrome and there may also be abnormal relaxation of the anterior abdominal musculature in these patients.

CONCLUSIONS

There is unlikely to be a single cause for bloating and distension, which probably have different, but overlapping, pathophysiological mechanisms. Relieving constipation might help distension, but the treatment of bloating may need more complex approaches involving sensory modulation.

Antidepressant therapy (imipramine and citalopram) for irritable bowel syndrome: a double-blind, randomized, placebo-controlled trial

BACKGROUND

The efficacy of antidepressants in irritable bowel syndrome (IBS) is controversial. No trials have directly compared a tricyclic with a selective serotonin reuptake inhibitor. Our aim was to determine whether imipramine and citalopram are efficacious in IBS.

METHODS

This was a randomized, double-blind, placebo-controlled, parallel group pilot trial with imipramine (50 mg) and citalopram (40 mg).

RESULTS

Of 51 IBS patients randomized, baseline characteristics were comparable among the treatment arms; the majority was diarrhea-predominant. Adequate relief of IBS symptoms (primary endpoint) was similar for each treatment arm. Improvements in bowel symptom severity rating for interference (P = 0.05) and distress (P = 0.02) were greater with imipramine versus placebo, but improvements in abdominal pain were not. There was a greater improvement in depression score (P = 0.08) and in the SF-36 Mental Component Score (P = 0.07), with imipramine. Citalopram was not superior to placebo. Approximately 20% of the variance in scores was explained by treatment differences for abdominal pain, bowel symptom severity disability, depression and the mental component of the SF-36.

CONCLUSION

Neither imipramine nor citalopram significantly improved global IBS endpoints over placebo.

Sympathetic (electrodermal) activity during repeated maximal rectal distensions in patients with irritable bowel syndrome and constipation

Irritable bowel syndrome (IBS) is associated with visceral hypersensitivity, stress and autonomic dysfunction. Sympathetic activity during repeated events indicates excitatory or inhibitory mechanisms such as sensitization or habituation. We investigated skin conductance (SC) during repetitive rectal distensions at maximal tolerable pressure in patients with IBS and chronic constipation. Twenty-seven IBS patients, 13 constipation patients and 18 controls underwent two sets of isobaric rectal distensions. First, maximal tolerable distension was determined and then it was repeated five times. Skin conductance was measured continuously. Subjective symptom assessment remained steady in all groups. The baseline values of SC were higher in IBS patients than in patients with constipation and significantly lower in constipation patients than in controls. The maximal SC response to repetitive maximal distensions was higher in IBS patients compared with constipation patients. The amplitude of the initial SC response decreased successively with increased number of distensions in patients with IBS and constipation but not in controls. Irritable bowel syndrome and constipation patients habituated to maximal repetitive rectal distensions with decreasing sympathetic activity. Irritable bowel syndrome patients had higher sympathetic reactivity and baseline activity than constipation patients. A lower basal SC in constipation patients compared with controls suggests an inhibition of the sympathetic drive in constipation patients.

Towards a nondualistic approach to multisystem illness

There is an increasing interest in understanding the etiology and treatment of patients who present with multiple chronic symptoms. The thesis of this comment is that the understanding of these problems and progress on effective treatment will be greatly enhanced by emerging new models that go beyond dualistic distinctions like those between organic versus functional disorders and psychological versus physiological causation. The outline of this new model includes a focus on common neurobiological and behavioral mechanisms that operate across disorders including altered pain modulation, affect regulation, and illness coping. Exciting new areas of research include functional and structural brain imaging studies and more recent studies linking imaging with genetic markers, behavior, and autonomic responses. These new studies, carried out across illness populations, hold great promise to tie together the data on psychosocial, genetic, and biological mechanisms of these complicated clinical problems.

Efficacy of dioctahedral smectite in treating patients of diarrhea-predominant irritable bowel syndrome

BACKGROUND AND AIM

Dioctahedral smectite (DS) is natural adsorbent clay useful in treating acute diarrhea. The aim of this study was to determine DS efficacy on patients with diarrhea-predominant irritable bowel syndrome (D-IBS in a phase III-, 8-week-randomized, double-blind, placebo-controlled trial.

METHODS

The 104 patients who met the D-IBS Rome II criteria were randomized to receive either DS (n = 52) or placebo (n = 52) treatment for 8 weeks (three sachets daily). The primary efficacy endpoint was the changes of the visual analog scale (VAS) score of IBS overall disorder and pain/discomfort-related symptoms after treatment on days 28 and 56, respectively. Other outcome measures included improvement of bowel movement disorders. The therapeutic global response was assessed by the patients and investigators at each visit, as was drug safety.

RESULTS

Both treatments diminished overall disorder at each visit (P < 0.01), with respect to primary efficacy. This effect was further observed in DS-treated patients on day 56 (P = 0.0167). Placebo had no effect on the VAS score of pain/discomfort at any visit, whereas DS improved this score on days 28 and 56, respectively (P < 0.05). DS and placebo similarly diminished bowel disorders at each visit; however, only DS improved abdominal bloating (P < 0.01). The global therapeutic responses evaluated by the patients and investigators were similarly distributed. The study drug was well tolerated during the 8-week period.

CONCLUSION

DS seems acceptable to treat D-IBS patients, particularly for pain-related symptoms.

Standardized concept for the treatment of gastrointestinal dysmotility in critically ill patients--current status and future options

Inhibition of gastrointestinal motility is a major problem in critically ill patients. Motor stasis gives rise to subsequent complications including intolerance to enteral feeding, enhanced permeability of the atrophic intestinal mucosa and conditions as severe as systemic inflammatory response syndrome, sepsis and multiple organ failure. Although the diagnosis of motility disturbances in critically ill patients is difficult, the type and site of the disturbance are important to consider in the analysis of the condition and in the choice of therapeutic approach. The pharmacological treatment of impaired gastrointestinal motility is difficult to handle for the clinician, because the underlying mechanisms are complex and not fully understood and the availability of pharmacological treatment options is limited. In addition, there is a lack of controlled studies on which to build an evidence-based treatment concept for critically ill patients. Notwithstanding this situation, there has been remarkable progress in the understanding of the integrated regulation of gastrointestinal motility in health and disease. These advances, which largely relate to the organization of the enteric nervous system and its signaling mechanisms, enable the intensivist to develop a standardized concept for the use of prokinetic agents in the treatment of impaired gastrointestinal motility in critically ill patients.

Characterisation of colonic accommodation in Wistar Kyoto rats with impaired gastric accommodation

Defective colonic and gastric accommodations have been related to altered viscerosensitivity in irritable bowel syndrome and to functional dyspepsia, respectively. We assessed colonic accommodation in rats with impaired gastric accommodation to determine if altered accommodation can be regarded as a widespread pathophysiological alteration within the gastrointestinal (GI) tract. Colonic accommodation during colorectal distension (CRD) was assessed in Wistar Kyoto rats (WKY), an animal model of impaired gastric accommodation, and in Sprague-Dawley (SD) and Wistar rats, considered normal. CRD (10-80 mmHg)-induced visceral pain responses were also evaluated in the same strains of rats. During gastric distension, WKY rats had lower intra-gastric volume (0.96 +/- 0.22 ml) than SD (1.85 +/- 0.19 ml, P < 0.05) or Wistar rats (2.80 +/- 0.26 ml, P < 0.05), indicating impaired gastric accommodation. In the same animals, pressure-volume curves were constructed during CRD as a measure of colonic accommodation. During short-lasting (1 min) phasic CRD (2-20 mmHg), the pressure-volume curve in WKY rats was displaced to the right compared with SD or Wistar rats, indicative of reduced colonic accommodation (maximal volume: SD, 1.22 +/- 0.05 ml; Wistar, 1.07 +/- 0.04 ml; WKY, 0.87 +/- 0.07 ml; P < 0.01). Pre-treatment with atropine normalised the pressure-volume responses in WKY rats. No differences among strains were observed during the 2-min phasic or ramp-tonic CRD. Visceral pain responses during CRD (10-80 mmHg) were, overall, similar in the three strains, although WKY rats showed lower thresholds for pain (28.0 +/- 4.9 mmHg) than SD (42.3 +/- 6.6 mmHg, P = 0.072) or Wistar rats (48.3 +/- 6.0 mmHg, P < 0.05). WKY rats, although having impaired gastric accommodation, have the ability to fully accommodate the colon to increasing pressures. In WKY rats, impaired accommodation of the smooth muscle might not be a widespread phenomenon along the GI tract but rather a local disturbance.

Why do subjects with irritable bowel syndrome seek health care for their symptoms?

OBJECTIVE

Irritable bowel syndrome (IBS) is common in the population, but not all subjects seek professional health care for their symptoms. The aim of this study was to compare consulters in secondary/tertiary care with those in primary care and non-consulters by using questionnaires to investigate factors of importance for health-care seeking in IBS.

MATERIAL AND METHODS

The study included 218 subjects with IBS: 70 non-consulters, 53 patients from primary care and 95 from secondary/tertiary care. The subjects completed questionnaires on gastrointestinal (GI) and psychological symptoms, coping resources, health-related quality of life (HRQOL) and reasons for not seeking health care.

RESULTS

Consulters (primary and secondary/tertiary care combined) had poorer HRQOL, more severe psychological symptoms, higher levels of GI-specific anxiety and poor coping resources compared with non-consulters, but the GI symptom severity was similar. Mental health and poor social, emotional and physical functioning were independently predictive of being a health-care seeker (r (2)=0.41). Independent predictors for being a consulter in secondary/tertiary care were a high degree of anxiety, low scores on physical functioning, physical role and food (IBSQOL) (r (2)=0.65). Several non-consulters reported mild symptoms and ability to control symptoms as reasons for not seeking health care. Having a close relative with similar symptoms reduced the need to seek health care. Thirty-six non-consulters had sought alternative care or advice from friends and/or relatives about their GI symptoms.

CONCLUSIONS

GI symptom severity alone cannot explain the illness behavior in IBS. HRQOL and psychological symptoms are important for experience of GI symptoms and the health-care seeking pattern in IBS.

Altered rectal perception in irritable bowel syndrome is associated with symptom severity

BACKGROUND & AIMS

Diverging results exist regarding the connection between altered visceral perception and gastrointestinal (GI) symptoms, as well as the effects of psychological status on visceral sensitivity. We sought to investigate different aspects of rectal perception in irritable bowel syndrome (IBS) and the association with GI and psychological symptoms.

METHODS

We included 109 patients with IBS meeting Rome II criteria (77 women; age range, 20-71 years) and 29 healthy controls (21 women; age range, 20-68 years). They underwent rectal balloon distentions determining sensory thresholds for discomfort and pain, the perceived intensity of unpleasantness, and the viscerosomatic referral area. The fifth percentile (thresholds) and 95th percentile (unpleasantness and referral area) in controls were used to define altered perception. Questionnaires were used to assess severity of IBS-related GI symptoms and psychological symptoms.

RESULTS

When combining the 3 aspects of perception, 67 patients (61%) had altered rectal perception. These patients, compared with normosensitive patients, more frequently reported moderate or severe pain (73% vs 44%; P < .01), bloating (73% vs 36%; P < .0001), diarrhea (47% vs 21%; P < .01), satiety (39% vs 13%; P < .01), and clinically significant anxiety (31% vs 12%; P < .05). In a multivariate analysis, only pain and bloating remained associated with altered rectal perception.

CONCLUSIONS

Altered rectal perception is common in IBS and seems to be one important pathophysiologic factor associated with GI symptom severity in general and pain and bloating in particular. It is not just a reflection of the psychological state of the patient.

Irritable bowel syndrome in psychiatric perspectives: a comprehensive review

We comprehensively reviewed the irritable bowel syndrome (IBS) in terms of pathogenesis, psychiatric implications, general management and appropriate role of antidepressants, in particular selective serotonin uptake inhibitors (SSRIs) in the treatment of IBS. English language papers cited in MEDLINE and PychInfo from January 2000 to July 2006 were searched with a combination of the following key words: irritable bowel syndrome, 5-HT, pathogenesis, comorbid, psychiatry, treatment, psychotropic drugs, antidepressant, selective serotonin reuptake inhibitors (fluoxetine, paroxetine, sertraline, fluvoxamine, citalopram and sertraline), tricyclic antidepressants, review, meta-analysis and placebo. The papers on IBS describing the clinical features, pathophysiology, evaluation, management, and clinical trials [randomised placebo-controlled trial (RCT), open-label study or case report] were selected for this review. Further literatures were also detected from references of the identified papers. The epidemiology, diagnostic criteria, pathophysiology, general management, bidirectional comorbidity, summary of currently available RCTs and open-label studies investigating antidepressant efficacy (focusing on SSRIs), and suggestions for SSRI use in IBS were relevantly synthesised based on through review of identified data. This article summarised an up-to-date clinical overview of IBS in psychiatric perspectives as well as to position a current role of SSRIs in the treatment of IBS. From this review, the routine use of SSRIs for IBS treatment cannot be conclusive due to a paucity of RCTs, although a handful of RCTs suggested a potentially beneficial effect of SSRIs over placebo.

Cilansetron in the treatment of diarrhea-predominant irritable bowel syndrome?

Information on the 5-hydroxytryptamine type 3 receptor antagonist cilansetron is scarce and most studies have only been published in abstract form. Results from preclinical and two dose-finding studies have suggested that cilansetron could be effective in the treatment of patients with diarrhea-predominant irritable bowel syndrome. Two large efficacy and safety trials extending over 3 and 6 months revealed a superiority of cilansetron 2 mg orally three-times daily over placebo reflected by numbers needed to treat of 4.8 and 5.6, respectively, for the parameter proportion of patients reporting adequate symptom relief. Dose-ranging studies showed no dose-response relationship. Cilansetron tended to induce constipation but, apart from transient ischemic colitis in four out of 1484 cases, no serious adverse effects were observed. Further trials are underway to fully determine the role of cilansetron in the treatment of diarrhea-predominant irritable bowel syndrome.

Subtyping the irritable bowel syndrome by predominant bowel habit: Rome II versus Rome III

BACKGROUND

The agreement between subtyping irritable bowel syndrome (IBS) patients based on Rome II criteria versus Rome III criteria is unknown.

AIM

To compare IBS subtyping based on Rome II versus III criteria.

METHODS

The Rome II Modular Questionnaire and the Bristol Stool Form Scale (one-week diary cards) were completed by 249 IBS patients. Based on the Rome II criteria, patients were defined as having diarrhoea- or constipation-predominant IBS, or alternating IBS. Based on the Rome III criteria, patients were divided into IBS with constipation, IBS with diarrhoea, mixed IBS or unsubtyped IBS. Agreement between Rome II and Rome III was assessed with kappa statistics.

RESULTS

Based on Rome II there were 92 diarrhoea-predominant IBS, 45 constipation-predominant IBS and 112 alternating IBS, and based on Rome III 97 IBS with diarrhoea, 77 IBS with constipation, 16 mixed IBS and 59 unsubtyped IBS. The agreement between Rome II and Rome III subgroups was 46% (kappa = 0.19). Changes from the constipation to the diarrhoea subgroups and vice versa were uncommon (8% of patients). The majority of changes occurred from/to the alternating IBS, mixed IBS and unsubtyped IBS subgroups.

CONCLUSION

There is poor agreement between subtyping of IBS patients based on Rome II versus Rome III criteria.

Evaluation of the pharmacological profile of ramosetron, a novel therapeutic agent for irritable bowel syndrome

We examined the pharmacological profile of ramosetron, a 5-HT(3)-receptor antagonist for irritable bowel syndrome with diarrhea, comparing it with those of other 5-HT(3)-receptor antagonists, alosetron and cilansetron, and the anti-diarrheal agent loperamide. Ramosetron showed high affinity for cloned human and rat 5-HT(3) receptors, with K(i) values of 0.091 +/- 0.014 and 0.22 +/- 0.051 nmol/L, respectively, while its affinities for other receptors, transporters, ion channels, and enzymes were negligible. Dissociation of ramosetron from the human 5-HT(3) receptor was extremely slow (t(1/2) = 560 min), while alosetron (t(1/2) = 180 min) and cilansetron (t(1/2) = 88 min) dissociated relatively rapidly. Ramosetron competitively inhibited 5-HT-induced contraction of isolated guinea-pig colon, with pA(2) values of 8.6 (8.5 - 9.0). Ramosetron given orally also dose-dependently inhibited the von Bezold-Jarisch reflex in rats, with an ED(50) value of 1.2 (0.93 - 1.6) microg/kg. In addition, oral ramosetron dose-dependently inhibited restraint stress-induced defecation in rats, with an ED(50) value of 0.62 (0.17 - 1.2) microg/kg. In all of these experiments, the potencies of ramosetron were greater than those of alosetron, cilansetron, or loperamide. These results indicate that ramosetron is a highly potent and selective 5-HT(3)-receptor antagonist, with beneficial effects against stress-induced abnormal defecation in rats.

The serotonin reuptake inhibitor citalopram does not affect colonic sensitivity or compliance in rats

Altered serotonin signaling has been implicated in the pathophysiology of irritable bowel syndrome (IBS). Selective serotonin reuptake inhibitors (SSRI) improve IBS symptoms, although the mechanism of action remains unclear. We assessed the effects of the SSRI, citalopram, on colonic sensitivity and compliance in rats after acute and repeated administration. Colorectal distension was performed in conscious rats. Pressure-volume relationships during colorectal distension (2-20 mmHg), fitted using a power exponential model [Vol=V(max)xexp[-(kappaxRelP)(beta)], were used as a measure of colonic compliance. The visceral pain-related visceromotor response during colorectal distension (10-80 mmHg) was used to assess visceral sensitivity. Pressure-volume curves and visceromotor responses were assessed after acute citalopram (3 or 10 mg/kg, ip) or vehicle and after repeated treatment (7 and 14 days; 3 or 10 mg/kg/day). In vehicle-treated animals, pressure-volume curves were similar over time. Citalopram (acute or repeated treatment) did not affect neither the pressure-volume curves nor the visceromotor response to colorectal distension. Thus, citalopram, after acute or repeated administration, had no significant effects on colon compliance or visceral pain during colorectal distension in rats. These results agree with recent observations in humans suggesting that the therapeutic actions of citalopram in IBS are independent of any effects on colonic sensorimotor function.

Effect of 5 days linaclotide on transit and bowel function in females with constipation-predominant irritable bowel syndrome

BACKGROUND & AIMS

Oral linaclotide, a novel agonist of guanylate cylase-C, stimulates intestinal fluid secretion and transit, and decreases visceral hypersensitivity in animal studies. In healthy volunteers, linaclotide was safe, well tolerated, increased stool frequency, and decreased stool consistency and time to first bowel movement. This randomized, double-blind, placebo-controlled study evaluated the effects of oral linaclotide, 100 and 1000 microg once daily, in 36 women with constipation-predominant irritable bowel syndrome; colonic transit was normal in >50% patients.

METHODS

Participants underwent 5-day baseline and 5-day treatment periods; gastrointestinal transit (by validated scintigraphy) and bowel function (by daily diaries) were assessed. Treatment effects were compared using analysis of covariance (baseline colonic transit as covariate) with pairwise comparisons of each dose vs placebo.

RESULTS

There was a significant overall treatment effect on ascending colon emptying half-time (P = .015) and overall colonic transit at 48 hours (P = .02) but not overall transit at 24 hours (P = ns), with a significant acceleration by linaclotide 1000 microg vs placebo (P = .004 and P = .01, respectively) but no significant effect of linaclotide 100-microg dose. There were significant overall treatment effects on stool frequency, stool consistency, ease of passage, and time to first bowel movement with a strong dose response for stool consistency (overall, P < .001). No safety issues were identified.

CONCLUSIONS

In women with constipation-predominant irritable bowel syndrome, linaclotide 1000 microg once daily significantly accelerated ascending colonic transit and altered bowel function. Further randomized controlled trials of clinical efficacy of linaclotide are warranted.

Use of health care resources and cost of care for adults with constipation

BACKGROUND & AIMS

Constipation is a multisymptom disorder that frequently compromises quality of life and leads patients to seek medical advice. To evaluate the clinical and fiscal effects of constipation, we assessed health care resource use by patients with constipation enrolled in a large state Medicaid program.

METHODS

We identified 105,130 patients older than age 18 who saw a physician at least once for constipation and were enrolled in the California Medicaid program (Medi-Cal). We then studied health care resource use and costs (reimbursed by Medi-Cal) in 76,854 patients without supplementary insurance. The 15-month analysis period encompassed 3 months before and 12 months after the first visit. The prevalence of comorbid conditions was assessed in the sample of 105,130 patients.

RESULTS

During the study period, 106,555 physician visits were for constipation; the total associated cost was $3,016,017 ($39/patient). The total cost for gastrointestinal procedures and laboratory testing was $14,052,503 ($183/patient). There were 41,723 over-the-counter and 1665 prescription drug purchases; the total cost was $388,780 ($5/patient). Approximately 0.6% of patients (n = 479) were admitted to the hospital for constipation; the total cost was $1,433,708 ($2993/admission). The total direct health care costs for patients with constipation in the Medi-Cal system for the 15-month period was $18,891,008 ($246/patient). Within 12 months of the first physician visit for constipation, 5657 of 105,130 patients had hemorrhoids and 2288 had intestinal impaction or obstruction.

CONCLUSIONS

Adults seeking treatment for constipation account for significant health care resource use and often have comorbid conditions. The clinical and fiscal burden of constipation in US adults cannot be disregarded or trivialized.

Irritable bowel syndrome: current approach to symptoms, evaluation, and treatment

There are frequent advances in knowledge about the clinical presentation, pathophysiology, and treatment of irritable bowel syndrome. It is important for clinicians to be aware of available therapies and the supporting evidence for those therapies to increase patient satisfaction. This is best achieved with a collaborative and long-term clinician-patient relationship and mutual commitment to modify therapy and try new modalities until the greatest relief of symptoms and improvement in health-related quality of life is achieved. This article reviews symptoms, comorbidities, gender differences, and measure of severity in irritable bowel syndrome and current and evidence-based approaches to evaluation and treatment, and the new symptom-based Rome III diagnostic criteria are reviewed and explained.

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.

The effects of regular consumption of short-chain fructo-oligosaccharides on digestive comfort of subjects with minor functional bowel disorders

A comparative, randomised, double-blind trial was performed in the medical departments of five hospitals to study the effects of regular consumption of short-chain fructo-oligosaccharides (sc-FOS) on the digestive comfort of subjects with minor functional bowel disorders (FBD). In step 1, 2235 subjects were questioned to assess the incidence and intensity of digestive disorders. In step 2, 105 of these patients diagnosed with minor FBD were randomised into two groups to receive either 5 g sc-FOS or 5 g placebo (sucrose and maltodextrins) per d over a 6-week period. The incidence and intensity of digestive disorders were assessed at the end of the treatment period (day 43) using the step 1 questionnaires. A quality-of-life questionnaire was also completed at the start and end of the treatment period to assess potential effects on well-being and social performance. In step 1, 44 % of the subjects questioned presented FBD, of whom 57.1 % suffered from minor FBD. In step 2, on day 43, the intensity of digestive disorders decreased by 43.6 % in the sc-FOS group v. a 13.8 % increase in the placebo group (P = 0.026). Symptoms were experienced less frequently by 75.0 % of subjects in the sc-FOS group, while 53.8 % of controls experienced no change (P = 0.064). Using the functional digestive disorders quality of life questionnaire, the discomfort item scores increased in the sc-FOS group (P = 0.031). However, expressed as change in quality of life (improvement, worsening or unchanged), daily activities were significantly improved in the sc-FOS group (P = 0.022). Regular consumption of sc-FOS may improve digestive comfort in a working population not undergoing medical treatment.

Constipation

Chronic constipation is a common disorder manifested by a variety of symptoms. Assessments of colonic transit and anorectal functions are used to categorize constipated patients into three groups, i.e., normal transit or irritable bowel syndrome, pelvic floor dysfunction (i.e., functional defaecatory disorders) and slow transit constipation. 'Slow transit' constipation is a clinical syndrome attributed to ineffective colonic propulsion and/or increased resistance to propagation of colonic contents. Defaecatory disorders are caused by insufficient relaxation of the pelvic floor muscles or a failure to generate adequate propulsive forces during defaecation. Colonic transit is often delayed in patients with functional defaecatory disorders. Normal and slow transit constipation are generally managed with medications; surgery is necessary for a minority of patients with slow transit constipation. Functional defaecatory disorders are primarily treated with pelvic floor retraining using biofeedback therapy.

Effect of a fermented milk containing Bifidobacterium animalis DN-173 010 on the health-related quality of life and symptoms in irritable bowel syndrome in adults in primary care: a multicentre, randomized, double-blind, controlled trial

BACKGROUND

Health-related quality of life (HRQoL) has been rarely evaluated as a primary endpoint in the assessment of the effect of probiotics on the irritable bowel syndrome (IBS).

AIM

To study the effects of fermented milk containing Bifidobacterium animalis DN-173 010 and yoghurt strains on the IBS in a multicentre, double-blind, controlled trial.

METHODS

A total of 274 primary care adults with constipation-predominant IBS (Rome II) were randomized to consume for 6 weeks either the test fermented milk or a heat-treated yoghurt (control). HRQoL and digestive symptoms were assessed after 3 and 6 weeks on an intention-to-treat population of 267 subjects.

RESULTS

The HRQoL discomfort score, the primary endpoint, improved (P < 0.001) in both groups at weeks 3 and 6. The responder rate for the HRQoL discomfort score was higher (65.2 vs. 47.7%, P < 0.005), as was the decrease in bloating score [0.56 +/- (s.d.)1.01 vs. 0.31 +/- 0.87, P = 0.03], at week 3 in the test vs. the control group. In those subjects with <3 stools/week, stool frequency increased (P < 0.001) over 6 weeks in the test vs. control group.

CONCLUSIONS

This study suggests a beneficial effect of a probiotic food on discomfort HRQoL score and bloating in constipation-predominant IBS, and on stool frequency in subjects with <3 stools/week.

A randomized, double-blind, placebo-controlled study to assess efficacy and safety of 0.5 mg and 1 mg alosetron in women with severe diarrhea-predominant IBS

OBJECTIVE

Alosetron is indicated for women with chronic, severe diarrhea-predominant IBS (d-IBS) who have not responded adequately to conventional therapy. Constipation is the most common adverse event with alosetron treatment. Multiple dosing regimens were assessed in a randomized, double-blind, placebo-controlled study (S3B30040) to determine efficacy, tolerability, and evaluate constipation rate.

METHODS

705 women with severe d-IBS were randomized to placebo, alosetron 0.5 mg once daily, 1 mg once daily, or 1 mg twice daily for 12 wk. The primary end point was the proportion of week 12 responders (patients with moderate or substantial improvement in IBS symptoms) on the 7-point Likert Global Improvement Scale (GIS). Secondary end points were average rate of adequate relief of IBS pain and discomfort, and bowel symptom improvements.

RESULTS

The proportion of GIS responders at week 12 (primary time point) was significantly greater in all alosetron groups compared with placebo (54/176 [30.7%], 90/177 [50.8%], 84/175 [48%], and 76/177 [42.9%] for placebo, 0.5, 1 mg once daily, and 1 mg twice daily alosetron groups, respectively; P< or = 0.02). Results were similar for the average adequate relief rate (treatment effects > or =12%, P< or = 0.038). Bowel symptoms were improved in all alosetron groups. Constipation was the most common adverse event (9%, 16%, and 19% patients in the 0.5 mg, 1 mg once daily, and 1 mg twice daily groups, respectively). One event of intestinal obstruction and one of ischemic colitis occurred in the 0.5 mg group, and one event of fecal impaction occurred in the 1 mg twice-daily group. All were self-limited and resolved without sequelae.

CONCLUSION

Alosetron 0.5 mg and 1 mg once daily as well as 1 mg twice daily are effective in providing global improvement in IBS symptoms, adequate relief of IBS pain and discomfort, and improvement in bowel symptoms in women with severe d-IBS. Lower dosing regimens resulted in a decreased constipation rate.

Overlap of gastro-oesophageal reflux disease and irritable bowel syndrome: prevalence and risk factors in the general population

BACKGROUND

Gastro-oesophageal reflux disease (GERD) and irritable bowel syndrome may occur more often than expected by chance, but little community data exists and risk factors are unknown.

AIM

To determine prevalence and risk factors for overlap of GERD and irritable bowel disease.

METHODS

Population-based, cross-sectional survey was conducted by mailing a valid symptom questionnaire to eligible residents of Olmsted County, MN, aged 30-95 years. Irritable bowel syndrome were defined by Rome III; GERD was defined by weekly or more frequent heartburn and/or acid regurgitation.

RESULTS

2298 questionnaires returned (women 52%, 55% response). Irritable bowel syndrome and GERD occurred together more commonly than expected by chance; the prevalence of irritable bowel syndrome-GERD overlap, GERD alone and irritable bowel syndrome alone were 3%, 15% and 5% in men, and 4%, 14% and 10% in women, respectively. Predictors of irritable bowel syndrome-GERD overlap vs. irritable bowel syndrome alone, and separately, GERD alone, were insomnia (OR 1.3, 95% CI: 1.06-1.70; OR 1.5, 95% CI: 1.13-1.90, respectively) and frequent abdominal pain (OR 3.9, 2.2-6.7; OR 1.8, 1.02-3.2, respectively). An additional predictor of irritable bowel syndrome-GERD overlap vs. GERD alone was higher somatization (OR 1.7, 1.1-2.4) and for irritable bowel syndrome-GERD overlap vs. irritable bowel syndrome alone was a higher body mass index (OR 1.0, 1.003-1.07).

CONCLUSIONS

Irritable bowel syndrome and GERD overlap is common in the population and does not occur by chance.

Irritable bowel syndrome

Irritable bowel syndrome (IBS) is a disease of unclear, complex pathophysiology characterised by abdominal pain and discomfort and altered bowel activity. It affects an estimated 10-15% of individuals worldwide and has a large impact on quality of life (QOL) and both direct and indirect healthcare costs. Symptoms of IBS are usually triggered by disruption of gastrointestinal (GI) function secondary to infection, dietary factors, lifestyle changes or psychological stress. While most currently available pharmacological treatments of IBS focus on symptomatic treatment of the syndrome, agents that attempt to address the pathophysiology of the disease, in particular the role of serotonin, have received much attention in recent years. However, there is growing concern that serotonergic agents as a class may be associated with rare, but serious, episodes of ischaemic colitis, with several cases of this complication having been reported in association with use of serotonergic agents that have reached the market. Thus, there remains an important need for safe and effective agents that treat the symptoms of IBS. Otilonium bromide, a spasmolytic agent, has been widely used worldwide and has been found to be effective and safe for managing abdominal pain. Clinical trials indicate that it improves baseline abdominal pain and distension, and is particularly effective in reducing diarrhoea. Combining otilonium bromide with benzodiazepines, such as diazepam, may improve the efficacy of the agent with respect to GI symptoms, while also treating underlying anxiety disorders. More research is required to confirm the efficacy and mechanisms of action associated with this combination therapy in IBS. Safety data from clinical trials and postmarketing sources indicate that otilonium bromide is well tolerated, with a safety profile comparable to placebo in clinical trials and only two reported cases of adverse reactions (urticaria) among 10-year postmarketing data. This article reviews the pathophysiology and treatment of IBS with a particular focus on the role of otilonium bromide in the management of this condition.

The burden of constipation on quality of life: results of a multinational survey

BACKGROUND

The impact of constipation on quality of life (QoL) may vary in different cultural or national settings.

AIM

We studied QoL in a multinational survey to compare different social and demographic groups with and without constipation (defined according to Rome III criteria) and to detect country-specific differences among the groups studied.

METHODS

Health-related QoL (HRQoL) was assessed with the Short Form 36 (SF-36) questionnaire in 2870 subjects in France, Germany, Italy, UK, South Korea, Brazil and USA. Results Respondents were mainly middle-aged, married or living together and part- or full-time employed. General health status, measured by the SF-36 questionnaire, was significantly worse in the constipated vs. non-constipated populations.

RESULTS

were comparable in all countries. QoL scores correlated negatively with age. Constipated women reported more impaired HRQoL than constipated men. Brazilians were most affected by constipation as to their social functioning (35.8 constipated vs. 51.3 non-constipated) and general health perception (29.4 constipated vs. 54.4 non-constipated).

CONCLUSIONS

There are significant differences in HRQoL between constipated and non-constipated individuals and a significant, negative correlation between the number of symptoms and complaints and SF-36 scores. The study detected a correlation of constipation with QoL and the influence of social and demographic factors on HRQoL in constipated people.

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.

The fecal microbiota of irritable bowel syndrome patients differs significantly from that of healthy subjects

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) is a significant gastrointestinal disorder with unknown etiology. The symptoms can greatly weaken patients' quality of life and account for notable economical costs for society. Contribution of the gastrointestinal microbiota in IBS has been suggested. Our objective was to characterize putative differences in gastrointestinal microbiota between patients with IBS and control subjects. These differences could potentially have a causal relationship with the syndrome.

METHODS

Microbial genomes from fecal samples of 24 patients with IBS and 23 controls were collected, pooled in a groupwise manner, and fractionated according to their guanine cytosine content. Selected fractions were analyzed by extensive high-throughput 16S ribosomal RNA gene cloning and sequencing of 3753 clones. Some of the revealed phylogenetic differences were further confirmed by quantitative polymerase chain reaction assays on individual samples.

RESULTS

The coverage of the clone libraries of IBS subtypes and control subjects differed significantly (P < .0253). The samples were also distinguishable by the Bayesian analysis of bacterial population structure. Moreover, significant (P < .05) differences between the clone libraries were found in several bacterial genera, which could be verified by quantitative polymerase chain reaction assays of phylotypes belonging to the genera Coprococcus, Collinsella, and Coprobacillus.

CONCLUSIONS

The study showed that fecal microbiota is significantly altered in IBS. Further studies on molecular mechanisms underlying these alterations are needed to elucidate the exact role of intestinal bacteria in IBS.

Opioid-induced bowel dysfunction: prevalence, pathophysiology and burden

As a result of the undesired action of opioids on the gastrointestinal (GI) tract, patients receiving opioid medication for chronic pain often experience opioid-induced bowel dysfunction (OBD), the most common and debilitating symptom of which is constipation. Based on clinical experience and a comprehensive MEDLINE literature review, this paper provides the primary care physician with an overview of the prevalence, pathophysiology and burden of OBD. Patients with OBD suffer from a wide range of symptoms including constipation, decreased gastric emptying, abdominal cramping, spasm, bloating, delayed GI transit and the formation of hard dry stools. OBD can have a serious negative impact on quality of life (QoL) and the daily activities that patients feel able to perform. To relieve constipation associated with OBD, patients often use laxatives chronically (associated with risks) or alter/abandon their opioid medication, potentially sacrificing analgesia. Physicians should have greater appreciation of the prevalence, symptoms and burden of OBD. In light of the serious negative impact OBD can have on QoL, physicians should encourage dialogue with patients to facilitate optimal symptomatic management of the condition. There is a pressing need for new therapies that act upon the underlying mechanisms of OBD.

[Stress-mast cell axis and regulation of gut mucosal inflammation: from intestinal health to an irritable bowel]

The functional gastrointestinal disorders and the irritable bowel syndrome, in particular, represent one of the commonest causes of medical consultation and the most frequent diagnosis raised by the gastroenterologists. Despite their high prevalence, the aetiology and pathophysiology of these functional digestive disorders remains unclear and specific diagnostic markers and clearly effective therapeutic options are lacking as well. These factors generate an important impairment in the quality of life in these patients and a growing sanitary burden. Recent studies showing the presence of low grade intestinal mucosal inflammation along with mast cell hyperplasia may contribute to the development and perpetuation of visceral hypersensitivity and dismotility patterns and epithelial barrier abnormalities, characteristic of the irritable bowel syndrome. In this article we will review the role of the stress-mast cell axis in the modulation of the gut mucosal inflammation and in the pathophysiology of the irritable bowel syndrome.

Irritable bowel syndrome and the Rome III criteria: for better or for worse?

The paper by Sperber et al. in this issue is an early evaluation of the Rome III criteria against the Rome II criteria for irritable bowel syndrome that throws up several important observations. A three to four-fold increase was observed in irritable bowel syndrome prevalence with the Rome III criteria. Individuals with the Rome II criteria had more doctor visits, perception of stress and a negative global feeling. There could be a shift of individuals between irritable bowel syndrome and other functional bowel disorder diagnostic groups such as functional constipation and functional bloating. In this review, it is suggested that rigid application of the symptom frequency and duration requirements of the older Rome criteria could have introduced a selection bias for patients with greater psychological disturbance, and that this could have impacted negatively on our perception and management of irritable bowel syndrome. The findings of Sperber et al. suggest that the new Rome III criteria may enable us to pay more attention to the average irritable bowel syndrome patient we see in our clinics as opposed to the chronically severe patient. It is proposed that improved management of our average patient may translate into better outcomes in terms of reduction in specialist referral, unnecessary surgery and potentially harmful alternative treatments.

A comparative reappraisal of the Rome II and Rome III diagnostic criteria: are we getting closer to the 'true' prevalence of irritable bowel syndrome?

OBJECTIVES

Revisions of the diagnostic criteria for irritable bowel syndrome have led to varying prevalence estimates. The Rome III criteria require a lower symptom frequency than Rome II (at least 10% of the time for Rome III, compared with at least 25% of the time for Rome II). In an epidemiological survey of a representative sample of Israeli adults using Rome II, we reported the prevalence for irritable bowel syndrome as 2.9%. The official Rome II integrative questionnaire, used for that study, enables a close approximation of Rome III rates, facilitating a retrospective comparison of these criteria.

METHODS

A representative sample of 1000 adults was interviewed with a validated Hebrew version of the official Rome II integrative questionnaire. The data were re-evaluated retrospectively to compare the Rome II results with a close approximation of the new Rome III criteria.

RESULTS

The prevalence rates for irritable bowel syndrome were 2.9 and 11.4%, respectively, for Rome II and Rome III. The corresponding consultation rates were 57.1 and 41.7%, indicating that the more strict Rome II criteria may select out a group of patients with more severe disease or greater psychosocial problems. Women made up 71.4% of irritable bowel syndrome by Rome II and 62.5% by Rome III.

CONCLUSIONS

In the present retrospective study, the prevalence rate for irritable bowel syndrome in our population is significantly higher by Rome III compared with Rome II. Rome III may more closely reflect the socioeconomic burden of irritable bowel syndrome compared with the overly strict Rome II. Prospective comparative studies should be conducted to confirm these results.

Lubiprostone: a chloride channel activator for treatment of chronic constipation

OBJECTIVE

To review lubiprostone's pharmacology, pharmacokinetics, efficacy, and safety in the treatment of chronic constipation.

DATA SOURCES

A literature search was conducted using PubMed/MEDLINE (1966-January 2007), IngentaConnect, and International Pharmaceutical Abstracts (1977-January 2007). Key words used included lubiprostone, Amitiza, and chronic constipation.

STUDY SELECTION AND DATA EXTRACTION

All articles identified from the data sources that were published in English were evaluated.

DATA SYNTHESIS

Lubiprostone is a chloride channel activator approved by the Food and Drug Administration for the treatment of chronic constipation. A randomized, double-blind, parallel-group, placebo-controlled study evaluating the effect of lubiprostone on gastric function showed slowed gastric emptying and increased small bowel and colonic transit time. Peak plasma concentration was shown to be around 1.14 hours, with a majority of the drug excreted in the urine within 48 hours. Phase III trials have noted that most patients with chronic constipation have a spontaneous bowel movement within 24 hours after taking lubiprostone. The most common adverse events in these trials were nausea, diarrhea, abdominal pain, and headache. Lubiprostone use has not been studied in the pediatric population.

CONCLUSIONS

Lubiprostone may be a reasonable alternative for use in patients who either fail or are intolerant of standard therapy for chronic constipation. Head-to-head comparison studies with conventional therapy are needed to contrast clinical efficacy and safety of this medication.

[Novel therapeutic approaches in the treatment of irritable bowel syndrome]

The treatment of irritable bowel syndrome due to the heterogeneous clinical symptoms and coexisting psychiatric disorders is still controversial. Although several agents with different mechanisms of action are widely used in clinical practice, there are only few drugs available with strong evidence of their efficacy, safety and tolerability at present. The etiology of irritable bowel syndrome is considered to be multifactorial: experimental and clinical research on visceral hypersensitivity, motility and brain-gut axis involving its neurotransmitters and receptors created the foundation of novel therapeutic approaches. Albeit nowadays several drugs (alosetron, tegaserod) have been registered in a few countries for the treatment of irritable bowel syndrome, further large clinical trials are required related to the new chemical entities.

Mitemcinal (GM-611), an orally active motilin agonist, facilitates defecation in rabbits and dogs without causing loose stools

The effects of mitemcinal (GM-611), an orally active motilin agonist, on defecation were investigated in rabbits and dogs. In normal rabbits, within 0-3 h of dosing, orally administered mitemcinal (2.5-10 mg kg(-1)) increased stool weight in a dose-dependent manner without causing loose stools. Sennoside (12-48 mg kg(-1)) also facilitated defecation within 2-9 h of oral administration, but the stools were significantly loosened. In the morphine-induced constipation model, the stool weight of morphine-treated rabbits (1 mg kg(-1)) was only 37.5% of that of untreated animals. Mitemcinal (0.5-20 mg kg(-1)) dose-dependently increased stool weight without increasing stool water content. At the highest dose of mitemcinal, stool weight recovered to 83.9% of that of untreated animals. In normal dogs, mitemcinal (0.3-3 mg kg(-1)) reduced the time to first bowel movement after oral administration without inducing diarrhoea at any dose. These results indicate that mitemcinal facilitates defecation without inducing severe diarrhoea. It is suggested that mitemcinal may be a novel therapeutic agent for constipation that enables easier control of the timing of defecation because of the early onset and short duration of its action, compared with sennoside.

Etiologies and predictors of diagnosis in nonresponsive celiac disease

BACKGROUND & AIMS

Nonresponsive celiac disease (NRCD) is a common problem affecting from 7% to 30% of celiac patients. Because NRCD comprises varied and potentially morbid entities, efficient and cost-effective patient care requires knowledge of the specific causes of this disorder. The aim of this study was to determine the common etiologies of NRCD in a tertiary referral center.

METHODS

All cases of biopsy examination-proven celiac disease (CD) seen at our institution over the preceding 5 years were included in this study. NRCD was defined as a failure to respond to at least 6 months of treatment with a gluten-free diet or the re-emergence of symptoms or laboratory abnormalities typical of CD while still on treatment with a gluten-free diet.

RESULTS

A total of 113 patients with NRCD meeting the earlier-described criteria were seen from a total of 603 patients with CD (19%), however, among patients for whom we provided primary specialist care the incidence of NRCD was 10% (P < .001). Gluten exposure was the most common cause of NRCD (36%), followed by irritable bowel syndrome (22%), refractory CD (10%), lactose intolerance (8%), and microscopic colitis (6%). The mean immunoglobulin A tissue transglutaminase level in the gluten-exposed group was 67 vs 17 U/mL (normal, <20) for other diagnoses (P < .05). Weight loss and male sex were highly predictive of refractory CD (P < .05 and < .001, respectively).

CONCLUSIONS

NRCD is a common phenomenon affecting 10%-19% of celiac patients. A limited number of etiologies account for the majority of cases. Clinical factors may be used to guide evaluation.