Systematic review: the efficacy of treatments for irritable bowel syndrome--a European perspective

Otilonium bromide in irritable bowel syndrome: A dose-ranging randomized double-blind placebo-controlled trial

AIM: To examine the efficacy and safety of otilonium bromide (OB) in treatment-sensitive functional irritable bowel syndrome (IBS) clinical parameters.

METHODS: Ninety-three patients (44.8 ± 12.6 years, 69% female) with IBS symptoms complying with Rome II criteria participated in this double-blind, placebo-controlled, randomised, dose-ranging phase I/II study. Patients were administered OB 20 mg (n = 24), 40mg (n = 23) and 80 mg (n = 23) tid or placebo (n = 23) in 4 parallel groups for 4 wk. Primary efficacy variables included abdominal discomfort, intestinal habits, number of daily evacuations and stool consistency. Secondary efficacy measures included return to regular intestinal habits and global discomfort. Safety was also assessed.

RESULTS: Baseline clinical characteristics were similar among the 4 groups. Although individual parameters such as intensity and frequency of abdominal discomfort, bloating or pain were reduced by OB over the 4 wk, no significant differences were observed between groups. Similarly, no difference was observed between OB treatment or placebo for mucus in stool and incomplete or difficulty of evacuation. However, evacuation frequency was significantly reduced after 4 wk by 80 mg OB compared to placebo (-8.36% for placebo vs -41.9% for 80 mg OB, P < 0.01). While 21.7% of patients in the placebo group experienced regular intestinal habits after 4 wk, this improvement was greater for patients treated with 40 mg OB (P < 0.01 vs placebo). Furthermore, a dose-dependent reduction in frequency of diarrhoea (χ²-test for trend = 11.5, P < 0.001) and an increase in normal stool frequency was observed. Combining individual variables into a global discomfort index revealed significant improvement among increasing OB doses, favouring 40 mg (P = 0.013) and 80mg OB (P = 0.001) over placebo. No difference was observed between frequency of adverse events for placebo vs OB.

CONCLUSION: This dose-ranging study demonstrates that OB at 40 and 80 mg can improve individual and global clinical symptoms of IBS compared to placebo over a 4-wk period.

Efficacy and safety of PPC-5650 on experimental rectal pain in patients with irritable bowel syndrome

PPC-5650 is a new pharmacological agent that can modulate acid-sensing ion channel activity, leading to a reduction in the pain signal under up-regulated conditions. The non-clinical programme for PPC-5650 supported a role for this novel agent in the treatment of pain in patients with irritable bowel syndrome (IBS). In patients with IBS, the aims of the study were: (1) to assess the efficacy of a single bolus of PPC-5650 locally applied in the rectum using multi-modal stimulations of the recto sigmoid and (2) to assess the safety profile of PPC-5650. The study was a randomized, double-blind, placebo-controlled, cross-over trial in patients with IBS, excluding females of child-bearing potential. The study consisted of a training visit, study visit 1 and 2 and a follow-up visit. Rectosigmoid electrical, thermal and mechanical stimulations were performed, pain perception was rated on a pain intensity scale and referred pain areas were assessed. All adverse events were registered. Twenty-five patients with IBS were enrolled and completed the study (9 women and 16 men; mean age 50.4 ± 12.7 years). No effects of the study drug were found on any of the rectal stimulations or for referred pain areas (all p > 0.05). No significant or clinically relevant treatment-related differences were seen for the laboratory safety variables or any other reported adverse event. In conclusion, in patients with IBS on rectal sensitivity to multi-modal stimulations, PPC-5650 did not produce efficacy relative to placebo. The overall safety and tolerability of PPC-5650 was acceptable.

Irritable bowel syndrome: A disease still searching for pathogenesis, diagnosis and therapy

Irritable bowel syndrome (IBS) is the most frequently diagnosed functional gastrointestinal disorder in primary and secondary care. It is characterised by abdominal discomfort, pain and changes in bowel habits that can have a serious impact on the patient’s quality of life. The pathophysiology of IBS is not yet completely clear. Genetic, immune, environmental, inflammatory, neurological and psychological factors, in addition to visceral hypersensitivity, can all play an important role, one that most likely involves the complex interactions between the gut and the brain (gut-brain axis). The diagnosis of IBS can only be made on the basis of the symptoms of the Rome III criteria. Because the probability of organic disease in patients fulfilling the IBS criteria is very low, a careful medical history is critical and should pay particular attention to the possible comorbidities. Nevertheless, the severity of the patient’s symptoms or concerns sometimes compels the physician to perform useless and/or expensive diagnostic tests, transforming IBS into a diagnosis of exclusion. The presence of alarming symptoms (fever, weight loss, rectal bleeding, significant changes in blood chemistry), the presence of palpable abdominal masses, any recent onset of symptoms in patient aged over 50 years, the presence of symptoms at night, and a familial history of celiac disease, colorectal cancer and/or inflammatory bowel diseases all warrant investigation. Treatment strategies are based on the nature and severity of the symptoms, the degree of functional impairment of the bowel habits, and the presence of psychosocial disorders. This review examines and discusses the pathophysiological aspects and the diagnostic and therapeutic approaches available for patients with symptoms possibly related to IBS, pointing out controversial issues and the strengths and weaknesses of the current knowledge.

Clinical characteristics of elderly patients with proton pump inhibitor-refractory non-erosive reflux disease from the G-PRIDE study who responded to rikkunshito

BACKGROUND

The incidence and severity of gastroesophageal reflux disease (GERD) in Japan tends to increase in elderly women. Rikkunshito (RKT), a traditional Japanese medicine, acts as a prokinetic agent and improves gastric emptying and gastric accommodation. Our previous prospective randomized placebo-controlled study showed that RKT combined with a standard-dose of rabeprazole (RPZ) significantly improved the acid-related dysmotility symptoms (ARD) in elderly patients with proton pump inhibitor (PPI)-refractory non-erosive reflux disease (NERD). This study aimed to evaluate clinical characteristics of elderly PPI-refractory NERD patients with ARD symptoms who responded to RKT.

METHODS

Two hundred forty-two patients with PPI-refractory NERD were randomly assigned to 8 weeks of either RPZ (10 mg/q.d.) + RKT (7.5 g/t.i.d.) (RKT group) or RPZ + placebo (PL group). Among them, 95 were elderly (≥65 years) with ARD (RKT group: n = 52; PL group: n = 43). We analyzed the changes using the 12 subscale score of frequency scale for the symptoms of GERD (FSSG) and 15 items of the Gastrointestinal Symptom Rating Scale at 4 and 8 weeks and compared the therapeutic efficacy between the 2 groups.

RESULTS

There were no marked differences in baseline demographic or clinical characteristics in the 2 groups except for rate of current smoking. The FSSG score (mean ± SD at 0, 4, and 8 weeks) in both the RKT (16.0 ± 7.0; 9.9 ± 8.4; 7.0 ± 6.4) and PL (15.1 ± 6.4; 10.9 ± 6.7, 11.1 ± 8.5) groups significantly decreased after treatment. However, the degree of improvement of total and ARD scores of FSSG after the 8-week treatment was significantly greater in the RKT group than in the PL group. Combination therapy with RKT for 8 weeks showed significant improvement in 3 subscale scores (abdominal bloating, heavy feeling in stomach and sick feeling after meals) of the ARD domain and 1 subscale score (heartburn after meals) of the reflux symptom domain.

CONCLUSIONS

RKT may be useful for improving GERD symptoms in elderly PPI-refractory NERD patients with ARD. Thus, RKT was particularly effective for resolving postprandial GERD symptoms (heavy feeling in stomach, sick feeling, and heartburn after meals).

TRIAL REGISTRATION

(UMIN000005880).

Linaclotide: A new drug for the treatment of chronic constipation and irritable bowel syndrome with constipation

INTRODUCTION

Linaclotide is the first member of a novel class of drugs to be extensively evaluated for the treatment of chronic constipation (CC) and irritable bowel syndrome with constipation (IBS-C).

AIM

To provide a comprehensive overview of the current state of knowledge on linaclotide, its pharmacological properties, mode of action and efficacy in clinical trials to date.

METHODS

We conducted a systematic review of the literature.

RESULTS

The survey revealed that linaclotide is a minimally absorbed, 14-amino acid peptide which acts in the intestinal lumen on guanylate cyclase-C (GC-C). This results in generation of cyclic guanosine monophosphate (cGMP), which stimulates chloride secretion, resulting in increased luminal fluid secretion and an acceleration of intestinal transit. In animal models, linaclotide also decreased visceral hypersensitivity. Linaclotide softened stool and increased transit in CC and in IBS-C. Phase II and phase III clinical studies established efficacy of linaclotide in CC (linaclotide 145 µg daily approved in the United States for CC) and in IBS-C (linaclotide 290 µg daily US Food and Drug Administration-approved for IBS-C, with favourable recommendation for the European Medicines Agency Committee for Medicinal Products for Human Use (CHMP). Linaclotide showed a favourable safety profile, and the main treatment-emerging adverse event was diarrhea, leading to discontinuation rates of up to 5%. Linaclotide is an important addition to the therapeutic possibilities for treating IBS-C and CC.

Irritable bowel syndrome: The evolution of multi-dimensional looking and multidisciplinary treatments

Irritable bowel syndrome (IBS) is common in the society. Among the putative pathogeneses, gut dysmotility results in pain and disturbed defecation. The latter is probably caused by the effect of abnormal gut water secretion. The interaction between abnormal gas accumulation, abdominal pain and bloating remains controversial. Visceral hypersensitivity and its modification along with the central transmission are the characteristics of IBS patients. The identification of biologic markers based on genetic polymorphisms is undetermined. Imbalanced gut microbiota may alter epithelial permeability to activate nociceptive sensory pathways which in turn lead to IBS. Certain food constituents may exacerbate bowel symptoms. The impact of adult and childhood abuses on IBS is underestimated. Using the concept of biopsychosocial dysfunction can integrate multidimensional pathogeneses. Antispasmodics plus stool consistency modifiers to treat the major symptoms and defecation are the first-line drug treatment. New drugs targeting receptors governing bowel motility, sensation and secretion can be considered, but clinicians must be aware of their potential serious side effects. Psychiatric drugs and modalities may be the final options for treating intractable subjects. Probiotics of multi-species preparations are safe and worth to be considered for the treatment. Antibiotics are promising but their long-term safety and effectiveness are unknown. Diet therapy including exclusion of certain food constituents is an economic measure. Using relatively safe complementary and alternative medicines (CAMs) may be optional to those patients who failed classical treatment. In conclusion, IBS is a heterogeneous disorder with multidimensional pathogeneses. Personalized medicines with multidisciplinary approaches using different classes of drugs, psychiatric measures, probiotics and antibiotics, dietary therapy, and finally CAMs, can be considered.

On-demand treatment with alverine citrate/simeticone compared with standard treatments for irritable bowel syndrome: results of a randomised pragmatic study

BACKGROUND

In routine practice, irritable bowel syndrome (IBS) symptoms are often difficult to be relieved and impair significantly patients' quality of life (QoL). A randomised, double-blind, placebo-controlled study has shown the efficacy of alverine citrate/simeticone (ACS) combination for IBS symptom relief.

AIM

As IBS symptoms are often intermittent, this pragmatic study was designed to compare the efficacy of an on-demand ACS treatment vs. that of usual treatments.

METHODS

Rome III IBS patients were enrolled by 87 general practitioners who were randomly allocated to one of two therapeutic strategies: on-demand ACS or usual treatment chosen by the physician. The primary outcome measure was the improvement of the IBSQoL score between inclusion and month 6.

RESULTS

A total of 436 patients (mean age: 54.4 years; women: 73.4%) were included, 222 in the ACS arm and 214 patients in the usual treatment arm, which was mainly antispasmodics. At 6 months, improvement of IBSQoL was greater with ACS than with the usual treatment group (13.8 vs. 8.4; p < 0.0008). The IBS-severity symptom score (IBS-SSS) was lower with ACS than in the usual treatment arm with a mean (SE) decrease of 170.0 (6.6) vs. 110.7 (6.7), respectively (p = 0.0001). An IBS-SSS < 75 was more frequent in the ACS group (37.7% vs. 16.0%; p < 0.0001). Improvement of both abdominal pain and bloating severity was also greater with the on-demand ACS treatment, which was associated with both lower direct and indirect costs.

CONCLUSIONS

After 6 months, on-demand ACS treatment led to a greater improvement of QoL, reduced the burden of the disease and was more effective for IBS symptom relief than usual treatments.

Irritable bowel syndrome: focus on otilonium bromide

Irritable bowel syndrome is a prevalent and chronic disorder, characterized by recurrent abdominal pain/discomfort, bloating and altered bowel habits. This condition affects an estimated 10-15% of the population worldwide and impacts heavily on a patient's daily life and ability to work, as well as healthcare resource utilization. Drug therapy aimed at correcting the primary symptoms of diarrhea/constipation/bloating may have little effect on abdominal pain, which results from visceral hypersensitivity. Smooth muscle relaxants or antispasmodics decrease the tone and contractility of intestinal smooth muscle, effectively managing abdominal pain. Otilonium bromide has been widely used worldwide and has been found to be safe and well tolerated, and superior to placebo for the reduction of symptoms and the prevention of symptom relapse in patients with irritable bowel syndrome.

A randomized controlled trial of brief psychoanalytic psychotherapy in patients with functional dyspepsia

Functional dyspepsia (FD) is a common cause of upper gastrointestinal symptoms and discomfort. The present study aimed to assess the effectiveness of brief core conflictual relationship theme (CCRT) psychoanalytic psychotherapy on changing gastrointestinal symptoms, alexithymia, and defense mechanisms in patients with FD. In a randomized controlled trial study, 49 patients with FD were randomly assigned to medical treatment with brief psychodynamic therapy (24 subjects) or medical treatment alone (25 subjects). Gastrointestinal symptoms, defense mechanisms, and alexithymia were assessed before the trial, after treatment, and at 1- and 12-month follow-ups. The results showed that brief psychodynamic therapy improved all of the gastrointestinal symptoms, including heartburn, nausea, fullness, bloating, upper abdominal pain, and lower abdominal pain, after treatment and at two follow-ups. The CCRT therapy significantly improved many psychological symptoms, including mature defenses, neurotic defenses, immature defenses, difficulties in identifying feelings, difficulties in describing feelings, and total alexithymia score. In conclusion, brief psychodynamic therapy is a reliable method to improve gastrointestinal symptoms, mature defenses, and alexithymia scores in patients with functional dyspepsia.

IBS and the role of otilonium bromide

INTRODUCTION

Awareness of the seriousness of irritable bowel disorder (IBS) remains low among clinicians. In this review, we summarize the current knowledge of IBS and highlight the major personal, economic, and social burden of the disease, and the importance of adequate treatment of what is still often viewed as a trivial disorder. In fact, IBS is a major reason for referral.

PATHOPHYSIOLOGY

It is crucial that the varied pathophysiologies of this complex heterogeneous disease are understood in order to be able to treat both the presenting symptoms (pain, bloating, flatulence, abnormal defecation, diarrhea, constipation) and the underlying disorder effectively. Low-grade inflammatory and immune activation has been observed, but the precise triggers and mechanisms, and the relevance to symptom generation, remain to be established.

TREATMENT

IBS patients require different treatment strategies according to the pattern, severity, frequency, and symptoms. While initial therapy traditionally targets the most bothersome symptom, long-term therapy aims at maintaining symptom control and preventing recurrence. In addition to dietary/lifestyle interventions and psychosocial strategies, a wide range of pharmacologic therapies are approved for use in IBS depending on the symptoms reported. Musculotropic spasmolytics, which act directly on intestinal smooth muscle contractility, such as otilonium bromide, are effective, particularly in the relief of abdominal pain and bloating, and are well tolerated in IBS. THE OBIS TRIAL: The recent large placebo-controlled Otilonium Bromide in Irritable Bowel Syndrome study demonstrated the superiority of otilonium bromide versus placebo not only in the reduction of pain and bloating, but also in protection from relapse due to the long-lasting effect.

Antibiotics for irritable bowel syndrome: rationale and current evidence

Irritable bowel syndrome (IBS) is the most common gastrointestinal condition effecting adults in developed countries worldwide. Over the last decade, evidence has emerged suggesting that gut bacteria play a role in the pathophysiology of IBS. While difficult to identify using noninvasive means, one of the most common attributable bacterial concepts in IBS is the small intestinal bacterial overgrowth hypothesis (SIBO). In this article, we review the different mechanisms by which gut flora and, specifically, SIBO may contribute to IBS and the evidence supporting the use of various antibiotic therapies in treating IBS.

Nutrient intake in patients with irritable bowel syndrome compared with the general population

BACKGROUND

Food and diet are central issues that concern patients with irritable bowel syndrome (IBS). Few studies have thoroughly analyzed dietary intake in IBS. Our aims were to determine the nutrient intake in IBS patients in comparison to the general population, assess nutritional differences between IBS subgroups based on the predominant bowel habit or symptom severity, as well as to evaluate if their nutrient intake meet nutrition recommendations.

METHODS

We included 187 IBS patients (mean 40.2 years; 139 women). They completed a 4-days food registration record, which was compared with an age-, and gender-matched control group (n = 374; 278 women) from a nation-wide dietary survey and with Nordic Nutrient Recommendations.

KEY RESULTS

Daily nutrient intake in IBS patients was similar to the general population and met national nutrients recommendations. Irritable bowel syndrome patients had similar energy distribution from macronutrients compared to the control group, but the protein percentage tended to be higher. Irritable bowel syndrome patients also had significantly higher daily intake of vitamin E, folate, iron, vitamin C, and dietary fibers, as well as lower intake of vitamin A, riboflavin, calcium, and potassium. There was no association between nutrient intake and IBS subtypes or symptom severity.

CONCLUSIONS & INFERENCES

Although many IBS patients state that they avoid food items, this does not seem to influence their intake of nutrients to any large extent. The observed minor differences in nutrient intake indicate a tendency toward higher intake of fruit and vegetables and a lower intake of meat and dairy products in IBS patients.

Treatment of irritable bowel syndrome: sex and gender specific aspects

Patients with functional gastrointestinal disorders constitute the majority of patients seeking healthcare for gastrointestinal symptoms in primary and secondary care. Of these disorders irritable bowel syndrome (IBS) is one of the most common and affects 10-20% in the Western world. IBS is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. Sex and gender aspects are important in understanding differences between men and women in their risk and experience of IBS. Relative to men, women are diagnosed more frequently with IBS. Female patients are more likely to be constipated, complain of abdominal distension and of certain extracolonic symptoms. Given the variability of IBS, the most successful treatment will be comprehensive, involving multiple strategies. Efficacy, safety and tolerability are important in the evaluation of IBS therapies, as patients are likely to require long-term treatment. Laxatives, antidiarrheals or antispasmodics are common in the treatment of IBS but the majority of patients receive antispasmodics followed by prokinetic agents. In treatment of IBS there appears to be a greater clinical response to serotonergic agents developed for IBS in women compared to men. There is an absence of drugs licensed specifically for the treatment of IBS. Further studies with novel agents are needed, to evaluate new approaches to IBS management including gender specific behavioral therapies and better characterization of patient subgroups with regard to drug therapy so that personalized therapy can be tested.

A clinicopathological study of serotonin of sigmoid colon mucosa in association with chronic symptoms in uncomplicated diverticulosis

INTRODUCTION

Neurotransmitter imbalance is hypothesised as a pathogenetic mechanism in several bowel conditions. We previously reported increased 5-HT in the sigmoid mucosa of colon resected for complicated diverticular disease (DD). We aimed to identify if abnormal 5-HT expression is associated with symptoms of uncomplicated DD.

METHODS

This was a prospective, comparative study and follow-up survey of symptoms. We examined the differences in 5-HT between DD patients and controls, as well as the presence of bowel symptoms at time of endoscopy and also 2 years later. Sigmoid biopsies were collected at colonoscopy. Immunohistochemical staining for 5-HT cells was performed.

RESULTS

Eighty-seven patients were recruited, 37 (42.5 %) DD and 50 (57.5 %) controls. No patients underwent surgery. There was no significant difference in total mean number of 5-HT-positive cells in DD compared to controls or between patients and controls with abdominal symptoms. Forty-one patients (47.1 %) responded to questionnaires at median 57.8 months from biopsy. Eighteen (43.9 %) were DD and 23(56.1 %) controls. 5-HT counts showed no significant association to symptom persistence.

DISCUSSION

Although 5-HT expression has previously been found to be increased in complicated DD in whole bowel-resected specimens, the same is not confirmed on colonic mucosal biopsies. This raises the suggestion that 5-HT may be involved in the development of acute complications but may not be involved in the pathogenesis of chronic symptoms.

Characteristics of deslanoside-induced modulation on jejunal contractility

AIM: To characterize the dual effects of deslanoside on the contractility of jejunal smooth muscle.

METHODS: Eight pairs of different low and high contractile states of isolated jejunal smooth muscle fragment (JSMF) were established. Contractile amplitude of JSMF in different low and high contractile states was selected to determine the effects of deslanoside, and Western blotting analysis was performed to measure the effects of deslanoside on myosin phosphorylation of jejunal smooth muscle.

RESULTS: Stimulatory effects on the contractility of JSMF were induced (45.3% ± 4.0% vs 87.0% ± 7.8%, P < 0.01) by deslanoside in 8 low contractile states, and inhibitory effects were induced (180.6% ± 17.8% vs 109.9% ± 10.8%, P < 0.01) on the contractility of JSMF in 8 high contractile states. The effect of deslanoside on the phosphorylation of myosin light chain of JSMF in low (78.1% ± 4.1% vs 96.0% ± 8.1%, P < 0.01) and high contractile state (139.2% ± 8.5% vs 105.5 ± 7.34, P < 0.01) was also bidirectional. Bidirectional regulation (BR) was abolished in the presence of tetrodotoxin. Deslanoside did not affect jejunal contractility pretreated with the Ca²⁺ channel blocker verapamil or in a Ca²⁺-free assay condition. The stimulatory effect of deslanoside on JSMF in a low contractile state (low Ca²⁺ induced) was abolished by atropine. The inhibitory effect of deslanoside on jejunal contractility in a high contractile state (high Ca²⁺ induced) was blocked by phentolamine, propranolol and L-NG-nitro-arginine, respectively.

CONCLUSION: Deslanoside-induced BR is Ca²⁺ dependent and is related to cholinergic and adrenergic systems when JSMF is in low or high contractile states.

Osteopathy improves the severity of irritable bowel syndrome: a pilot randomized sham-controlled study

BACKGROUND

Effective therapies for irritable bowel syndrome (IBS) are disappointing. Therefore, IBS patients have a growing interest for alternative medicines including osteopathy.

AIM

We aimed to evaluate the effect of osteopathy on the severity of IBS in a randomized sham-controlled trial.

METHODS

We prospectively assigned 30 patients with IBS (23F, 7M, mean age 45.8±16.4 years) fulfilling the Rome III criteria in a 2/1 ratio to receive either osteopathy or sham osteopathy. Two separate sessions were performed at a 7-day interval (days 0 and 7) with a further 3 weeks of follow-up (day 28). The primary outcome included at least a 25% improvement in the IBS severity score at day 7. The secondary outcomes included the impact of IBS on quality of life, psychological factors, and bowel habits.

RESULTS

The severity of IBS decreased in both groups at days 7 and 28. At day 7, this decrease was significantly more marked in patients receiving osteopathy compared with those receiving the sham procedure (-32.2±29.1 vs. -9.0±16.0, mean difference normalized to the baseline P=0.01). This difference did not persist at day 28 (P=0.4). Both anxiety and depression scores decreased without difference between groups. Stool frequency and consistency were not significantly modified.

CONCLUSION

Osteopathy improves the severity of IBS symptoms and its impact on quality of life. Osteopathy should therefore be considered for future research as an effective complementary alternative medicine in the management of IBS symptoms.

Effect of antispasmodic agents, alone or in combination, in the treatment of Irritable Bowel Syndrome: systematic review and meta-analysis

INTRODUCTION

Irritable bowel syndrome (IBS) is characterized by recurrent abdominal pain, bloating, and changes in bowel habit.

AIMS

To determine the clinical effectiveness of the antispasmodic agents available in Mexico for the treatment of IBS.

METHODS

We carried out a systematic review and meta-analysis of randomized controlled clinical trials on antispasmodic agents for IBS treatment. Clinical trials identified from January 1960 to May 2011 were searched for in MEDLINE, the Cochrane Library, and in the ClinicalTrials.gov registry. Treatment response was evaluated by global improvement of symptoms or abdominal pain, abdominal distention/bloating, and frequency of adverse events. The effect of antispasmodics vs placebo was expressed in OR and 95% CI.

RESULTS

Twenty-seven studies were identified, 23 of which fulfilled inclusion criteria. The studied agents were pinaverium bromide, mebeverine, otilonium, trimebutine, alverine, hyoscine, alverine/simethicone, pinaverium/simethicone, fenoverine, and dicyclomine. A total of 2585 patients were included in the meta-analysis. Global improvement was 1.55 (CI 95%: 1.33 to 1.83). Otilonium and the alverine/simethicone combination produced significant values in global improvement while the pinaverium/simethicone combination showed improvement in bloating. As for pain, 2394 patients were included with an OR of 1.52 (IC 95%: 1.28 a 1.80), favoring antispasmodics.

CONCLUSIONS

Antispasmodics were more effective than placebo in IBS, without any significant adverse events. The addition of simethicone improved the properties of the antispasmodic agents, as seen with the alverine/simethicone and pinaverium/simethicone combinations.

Anxiety-depressive disorders among irritable bowel syndrome patients in Guilan, Iran

BACKGROUND

Psychiatric disorders are common in irritable bowel syndrome (IBS) patients. The prevalence of psychiatric disorders in IBS patients varies in different cultures. We conducted this study to determine the prevalence of psychiatric disorders

METHODS

In a cross-sectional study, 256 IBS patients were selected (using the criteria of Rome III) and evaluated for psychiatric disorders. In the first phase, subjects were screened using the General Health Questionnaire 28 (GHQ28). In the second phase, those who had scores ≥ 23 were assessed through semi-structured psychiatric interviews.

RESULTS

Thirty out of 256 subjects had no significant psychiatric symptoms after performing GHQ28. In further psychiatric evaluation of the remaining subjects (226) who suffered from some degree of a psychiatric problem, 36 were diagnosed without Anxiety/Depressive disorder. Thus 66 subjects (25.8%) were known as a group without any significant psychiatric problem. A total of 190 subjects (74.2%) with anxiety-depressive problems were diagnosed; 89 were suffering from pure anxiety disorders, 41 were suffering from depressive disorders and 60 had co-morbid anxiety-depressive disorders. When comparing anxiety-depressive patients (n = 190) with normal subjects (n = 66), gender (P = 0.016), occupation (P = 0.002) and intensity of IBS (P < 0.001) showed statistically significant differences.

CONCLUSION

The high prevalence of anxiety-depressive disorders in this study indicates the necessity of psychiatric assessment, early diagnosis and treatment of the patients with IBS. It may improve management of the patients suffering from IBS.

Crofelemer for the treatment of secretory diarrhea

Secretory diarrhea is a leading cause of morbidity and mortality worldwide. Crofelemer is a first-in-class antidiarrheal agent that simultaneously targets two distinct channels, the cystic fibrosis conductance regulator and calcium-activated chloride channel, responsible for chloride and fluid secretion in the GI tract. Crofelemer is a novel compound extracted from the stem bark latex of the Croton lechleri tree found in the western Amazonian region of South America. There is little to no systemic absorption of crofelemer when given orally and studies have shown minimal toxicity beyond mild gastrointestinal effects. In studies in diarrheal illness associated with primarily a secretory component, such as cholera, travelers' diarrhea and acute infectious diarrhea, crofelemer has shown improvements in stool consistency and duration of symptoms. Less clear, but interesting, results have been observed in other diarrheal diseases associated with a mixed pathology, including diarrhea in patients with HIV and diarrhea-predominant irritable bowel syndrome.

Treatment of IBS-D with 5-HT3 receptor antagonists vs spasmolytic agents: similar therapeutical effects from heterogeneous pharmacological targets

There is still no agreement over optimal pharmacological treatment for irritable bowel syndrome (IBS). Patients with IBS and diarrhea (IBS-D) demonstrate both visceral hypersensitivity and impaired colonic motility with increased frequency and amplitude of giant migrating contractions (GMCs) which cause mass movements, propulsion of stools and initiation of defecation. Both antispasmodics and 5-HT3 receptor antagonists can improve the symptoms and the impaired colonic motility of patients with IBS-D though through very different mechanisms. Antispasmodics act by directly relaxing the colonic smooth muscle cells or antagonizing the excitatory neuromuscular neurotransmission. In contrast, the mechanism of action of 5HT3 antagonists is much more complex and subtle as they inhibit the ascending excitatory component of the peristaltic reflex and GMCs. There are some concerns about the safety of 5HT3 antagonists in long-term treatment. Most of the studies on the treatment of IBS have followed the pharmacological strategy of looking for big clinical effects acting on a single receptor/target. We propose a pharmacologic strategy which uses different drugs for pain and dysmotility in the same patient and includes specific drugs acting on smooth muscle cells, neuromuscular transmission, synaptic transmission and intrinsic afferents. The clinical effect on IBS symptoms would be found in the sum of all these smaller effects on multiple targets.

Bulking agents, antispasmodics and antidepressants for the treatment of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder. The role of pharmacotherapy for IBS is limited and focused mainly on symptom control.

OBJECTIVES

The objective of this systematic review was to evaluate the efficacy of bulking agents, antispasmodics and antidepressants for the treatment of irritable bowel syndrome.

SEARCH STRATEGY

Computer assisted structured searches of MEDLINE, EMBASE, The Cochrane library, CINAHL and PsychInfo were conducted for the years 1966-2009. An updated search in April 2011 identified 10 studies which will be considered for inclusion in a future update of this review.

SELECTION CRITERIA

Randomized controlled trials comparing bulking agents, antispasmodics or antidepressants with a placebo treatment in patients with irritable bowel syndrome aged over 12 years were considered for inclusion. Only studies published as full papers were included. Studies were not excluded on the basis of language. The primary outcome had to include improvement of abdominal pain, global assessment or symptom score.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from the selected studies. Risk Ratios (RR) and Standardized Mean Differences (SMD) with 95% confidence intervals (CI) were calculated. A proof of practice analysis was conducted including sub-group analyses for different types of  bulking agents, spasmolytic agents or antidepressant medication. This was followed by a proof of principle analysis where only the studies with adequate allocation concealment were included.

MAIN RESULTS

A total of 56 studies (3725 patients) were included in this review. These included 12 studies of bulking agents (621 patients), 29 of antispasmodics (2333 patients), and 15 of antidepressants (922 patients). The risk of bias was low for most items. However, selection bias is unclear for many of the included studies because the methods used for randomization and allocation concealment were not described. No beneficial effect for bulking agents over placebo was found for improvement of abdominal pain (4 studies; 186 patients; SMD 0.03; 95% CI -0.34 to 0.40; P = 0.87), global assessment (11 studies; 565 patients; RR 1.10; 95% CI 0.91 to 1.33; P = 0.32) or symptom score (3 studies; 126 patients SMD -0.00; 95% CI -0.43 to 0.43; P = 1.00). Subgroup analyses for insoluble and soluble fibres also showed no statistically significant benefit. Separate analysis of the studies with adequate concealment of allocation did not change these results. There was a beneficial effect for antispasmodics over placebo for improvement of abdominal pain (58% of antispasmodic patients improved compared to 46% of placebo; 13 studies; 1392 patients; RR 1.32; 95% CI 1.12 to 1.55; P < 0.001; NNT = 7), global assessment (57% of antispasmodic patients improved compared to 39% of placebo; 22 studies; 1983 patients; RR 1.49; 95% CI 1.25 to 1.77; P < 0.0001; NNT = 5) and symptom score (37% of antispasmodic patients improved compared to 22% of placebo; 4 studies; 586 patients; RR 1.86; 95% CI 1.26 to 2.76; P < 0.01; NNT = 3). Subgroup analyses for different types of antispasmodics found statistically significant benefits for cimteropium/ dicyclomine, peppermint oil, pinaverium and trimebutine. Separate analysis of the studies with adequate allocation concealment found a significant benefit for improvement of abdominal pain. There was a beneficial effect for antidepressants over placebo for improvement of abdominal pain (54% of antidepressants patients improved compared to 37% of placebo; 8 studies; 517 patients; RR 1.49; 95% CI 1.05 to 2.12; P = 0.03; NNT = 5), global assessment (59% of antidepressants patients improved compared to 39% of placebo; 11 studies; 750 patients; RR 1.57; 95% CI 1.23 to 2.00; P < 0.001; NNT = 4) and symptom score (53% of antidepressants patients improved compared to 26% of placebo; 3 studies; 159 patients; RR 1.99; 95% CI 1.32 to 2.99; P = 0.001; NNT = 4). Subgroup analyses showed a statistically significant benefit for selective serotonin releasing inhibitors (SSRIs) for improvement of  global assessment and for tricyclic antidepressants (TCAs) for improvement of abdominal pain and symptom score. Separate analysis of studies with adequate allocation concealment found a significant benefit for improvement of symptom score and global assessment. Adverse events were not assessed as an outcome in this review.

AUTHORS' CONCLUSIONS

There is no evidence that bulking agents are effective for treating IBS.  There is evidence that antispasmodics are effective for the treatment of IBS. The individual subgroups which are effective include: cimetropium/dicyclomine, peppermint oil, pinaverium and trimebutine. There is good evidence that antidepressants are effective for the treatment of IBS. The subgroup analyses for SSRIs and TCAs are unequivocal and their effectiveness may depend on the individual patient. Future research should use rigorous methodology and valid outcome measures.

Randomised clinical trial: otilonium bromide improves frequency of abdominal pain, severity of distention and time to relapse in patients with irritable bowel syndrome

BACKGROUND

Otilonium bromide (OB) is a spasmolytic agent that blocks L-Type Calcium channels in human colonic smooth muscle.

AIM

To study the efficacy of OB in symptom control in irritable bowel syndrome (IBS).

METHODS

A total of 356 patients (46.16±19years, 71% female) with IBS participated in a double-blind, randomised, parallel placebo-controlled phase IV study. OB (40mg t.d.s.) or placebo was administered for 15weeks, and follow-up was extended 10 additional weeks.

RESULTS

Otilonium bromide (n=179) and placebo (n=177) groups had comparable demographics, symptom severity and IBS subtype. Both OB and placebo reduced abdominal pain and IBS symptoms. The effect of OB was significantly greater than placebo in the reduction of weekly frequency of episodes of abdominal pain at the end of treatment period (primary endpoint, -0.90±0.88 vs. -0.65±0.91, P=0.03), reduction of abdominal bloating (-1.2±1.2 vs. -0.9±1.1, P=0.02) and global efficacy by patient assessment (1.3±1.1 vs. 1.0±1.1, P=0.047). Intensity of abdominal pain, proportion of patient responders, safety and quality of life scores were similarly affected by OB and placebo. During follow-up, the therapeutic effect of OB remained greater than placebo in terms of withdrawal rate due to symptom relapse (10% vs. 27%, P=0.009), global efficacy of treatment and relapse-free probability (P=0.038).

CONCLUSIONS

This placebo-controlled double-blind study shows that otilonium bromide is safe, well tolerated and superior to placebo in reducing the frequency of abdominal pain, severity of abdominal bloating and protecting from symptom relapse in IBS. These results further confirm that patients with IBS can improve during and following treatment with otilonium bromide.

[Guidelines for the treatment of irritable bowel syndrome]

Traditional symptom-based therapies of irritable bowel syndrome (IBS) are directed at the relief of individual IBS symptoms, but they are often of limited efficacy in addressing the entire symptom complex. Combinations of drugs to target bothersome symptoms are suggested as the first-line pharmacologic treatment. Increasing knowledge of the pathophysiology and molecular mechanisms of IBS has resulted in the development of several new therapeutic approaches. Thirteen consensus statements for the treatment of IBS were developed using the modified Delphi approach. Exclusion diets have modest efficacy in improving symptoms in some IBS patients. Symptom-based therapies with dietary fiber, bulking agents, laxatives, antispasmodics and laxatives are effective in the improvement of some individual symptoms, e.g. dietary fiber and bulking agents for constipation, laxatives for constipation, antispasmodics for abdominal pain and discomfort, antidiarrheals for diarrhea. 5HT3 receptor antagonists and 5HT((4)) receptor agonists are effective in the relief of global IBS symptoms and individual symptoms such as abdominal pain and abnormal bowel habits. A short term course of nonabsorbable antibiotics may improve global IBS symptoms, particularly in patients with diarrhea- predominant IBS. Some probiotics appear to have the potential benefit in improving global IBS symptoms. Selective C-2 chloride channel activator is more effective than placebo at relieving global IBS symptoms in patients with constipation-predominant IBS. Both tricyclic antidepressants and selective serotonin reuptake inhibitors are equally effective in relieving global IBS symptoms, and have some benefits in treating abdominal pain. Certain types of psychologic therapy may be effective in improving global symptoms in some IBS patients. Further studies are strongly needed to develop better treatment strategies for Korean patients with IBS.

Review article: the pathogenesis of diverticular disease--current perspectives on motility and neurotransmitters

BACKGROUND

Low-fibre diet, structural abnormalities and ageing are traditional aetiological factors implicated in the development of diverticular disease. More recently, motility disorders are implicated in its causation leading to speculation that neurotransmitters play a role in mediating these disturbances.

AIMS

To draw together studies on the role of neurotransmitters in the development of diverticular disease and its symptoms.

METHODS

Medline, GoogleScholar and Pubmed were searched for evidence on this subject using the terms neurotransmitters, motility, diverticular disease and pathogenesis. Articles relevant to the subject were cited and linked references were also reviewed.

RESULTS

Serotonin, which has been found to be an excitatory colonic neurotransmitter, has been found in early studies to be increased in colonic enterochromaffin cells. Acetylcholine, which is thought to be an excitatory neurotransmitter and cholinergic activity, has also seen to be increased in diverticular disease. These findings may suggest that an increase in excitatory neurotransmitters may result in the hypersegmentation thought to cause pulsion diverticula. Similarly, a decrease in nitric oxide which is inhibitory is found.

CONCLUSIONS

There is some evidence that neurotransmitters may play a role in the motility disturbances seen in diverticular disease; however, a clear role is yet to be ascertained.

Dysfunctional cognitions, anxiety and depression in irritable bowel syndrome

GOALS AND BACKGROUND

Patients with irritable bowel syndrome (IBS) have significantly impaired quality of life (QoL). We investigated the presence of dysfunctional cognitions, anxiety, and depression symptoms and their impact on daily symptoms and QoL in a large IBS cohort.

STUDY

A total of 268 IBS patients (Rome II criteria, age 18 to 65 y) were included. Patients completed a 2-week daily symptom diary. The Short Form-36 was used to score QoL. The 31-items Cognitive Scale for Functional Bowel Disorders (CSFBD) and the Hospital Anxiety and Depression Scale (HADS) were used to analyze the psychological factors.

RESULTS

Possible anxiety and depression disorders were present in 30% and 22% of IBS patients, respectively. Patients with anxiety and depression had significantly higher mean symptom scores, impaired QoL, and higher CSFBD scores (P<0.01). Physical and mental QoL were both affected by depression (HADS-D) and dysfunctional cognitions (P<0.01). Only physical QoL, not mental QoL, was affected by referral type (hospital setting vs. community based; P<0.01). Only mental QoL was affected by anxiety (HADS-A) (P<0.01). Dysfunctional cognitions independently of anxiety and depression influenced QoL and IBS symptoms.

CONCLUSIONS

In this IBS cohort, dysfunctional cognitions independently influence physical and mental QoL and symptom severity. Presence of possible anxiety and depression disorders resulted in higher symptoms, lower QoL, and higher CSFBD scores. The results point toward an important role of psychological factors, especially dysfunctional cognitions on QoL and symptom scores in IBS patients.

Effectiveness of trimebutine maleate on modulating intestinal hypercontractility in a mouse model of postinfectious irritable bowel syndrome

Trimebutine maleate, which modulates the calcium and potassium channels, relieves abdominal pain in patients with irritable bowel syndrome. However, its effect on postinfectious irritable bowel syndrome is not clarified. The aim of this study was to investigate the effectiveness of trimebutine maleate on modulating colonic hypercontractility in a mouse model of postinfectious irritable bowel syndrome. Mice infected up to 8 weeks with T. spiralis underwent abdominal withdrawal reflex to colorectal distention to evaluate the visceral sensitivity at different time points. Tissues were examined for histopathology scores. Colonic longitudinal muscle strips were prepared in the organ bath under basal condition or to be stimulated by acetylcholine and potassium chloride, and consecutive concentrations of trimebutine maleate were added to the bath to record the strip responses. Significant inflammation was observed in the intestines of the mice infected 2 weeks, and it resolved in 8 weeks after infection. Visceral hyperalgesia and colonic muscle hypercontractility emerged after infection, and trimebutine maleate could effectively reduce the colonic hyperreactivity. Hypercontractility of the colonic muscle stimulated by acetylcholine and high K(+) could be inhibited by trimebutine maleate in solution with Ca(2+), but not in Ca(2+) free solution. Compared with 8-week postinfectious irritable bowel syndrome group, 2-week acute infected strips were much more sensitive to the stimulators and the drug trimebutine maleate. Trimebutine maleate was effective in reducing the colonic muscle hypercontractility of postinfectious irritable bowel syndrome mice. The findings may provide evidence for trimebutine maleate to treat postinfectious irritable bowel syndrome patients effectively.

Effect of otilonium bromide on contractile patterns in the human sigmoid colon

BACKGROUND

The mechanism of action of the spasmolytic compound otilonium bromide (OB) on human colonic motility is not understood. The aim of our study was to characterize the pharmacological effects of OB on contractile patterns in the human sigmoid colon.

METHODS

Circular sigmoid strips were studied in organ baths. Isolated smooth muscle cells from human sigmoid colon were examined using the calcium imaging technique.

KEY RESULTS

Otilonium bromide inhibited by 85% spontaneous non-neural rhythmic phasic contractions (RPCs), (IC(50) = 49.9 nmol L(-1)) and stretch-induced tone (IC(50) = 10.7 nmol L(-1)) with maximum effects at micromolar range. OB also inhibited by 50% both on- (IC(50) = 38.0 nmol L(-1)) and off-contractions induced by electrical stimulation of excitatory motor neurons. In contrast, the inhibitory latency period prior to off-contractions was unaffected by OB. OB inhibited acetylcholine-, substance P-, and neurokinin A-induced contractions. The L-type Ca(2+) channel agonist BayK8644 reversed the effects of OB on RPCs, on- and off-contractions. Hexamethonium, atropine, the NK(2) antagonist, or depletion of intracellular Ca(2+) stores by thapsigargin did not prevent the inhibitory effect of OB on RPCs and electrical contractions. KCl-induced calcium transients in isolated smooth muscle cells were also inhibited by OB (IC(50) = 0.2 micromol L(-1)).

CONCLUSIONS & INFERENCES

Otilonium bromide strongly inhibited the main patterns of human sigmoid motility in vitro by blocking calcium influx through L-type calcium channels on smooth muscle cells. This pharmacological profile may mediate the clinically observed effects of the drug in patients with irritable bowel syndrome.

Treatment of psychological co-morbidities in common gastrointestinal and hepatologic disorders

Anxiety and depressive disorders frequently coexist with gastrointestinal and hepatologic conditions. Despite their high prevalence, approach to treating these co-morbidities is not always straightforward. This paper aims to review the current literature into etiology of psychological co-morbidities and their treatment in three conditions commonly encountered at gastroenterology outpatient clinics, namely inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) and chronic hepatitis C (HepC). The paper demonstrates that although psychotherapy (and cognitive-behavioural therapy in particular) has been established as an effective treatment in IBS, more studies are needed in HepC and IBD. Antidepressants have been recognized as an effective treatment for psychological and somatic symptoms in IBS and for depression in HepC, but good quality studies in IBD are lacking despite the promising preliminary findings from animal models and case studies. Further studies in this area are needed.

Clinical trial: the efficacy of alverine citrate/simeticone combination on abdominal pain/discomfort in irritable bowel syndrome--a randomized, double-blind, placebo-controlled study

BACKGROUND

Alverine citrate and simeticone combination has been used for almost 20 years in irritable bowel syndrome (IBS), but supportive scientific evidence of efficacy was limited.

AIM

To evaluate the efficacy of alverine citrate and simeticone combination in patients with IBS-related abdominal pain/discomfort.

METHODS

A total of 412 IBS patients meeting ROME III criteria were included in this double-blind randomized placebo-controlled study if their abdominal pain/discomfort intensity was at least 60 mm on a 0-100 mm visual analogue scale (VAS) during a 2-week run-in treatment-free period. Patients were randomly assigned through the use of Interactive Voice Response System to receive either alverine citrate 60 mg with simeticone 300 mg three times daily or matching placebo for 4 weeks.

RESULTS

The full analysis set included 409 patients (71.4% female: mean age: 46.2 +/- 13.9 years). At week 4, alverine citrate and simeticone group had lower VAS scores of abdominal pain/discomfort (median: 40 mm vs. 50 mm, P = 0.047) and higher responder rate (46.8% vs. 34.3%, OR = 1.3; P = 0.01) as compared with placebo group. Patient receiving alverine citrate and simeticone reported greater global symptom improvement compared with those receiving placebo (P = 0.0001). Reported adverse events were similar in both groups.

CONCLUSION

Alverine citrate/simeticone combination was significantly more effective than placebo in relieving abdominal pain/discomfort in patients with IBS.

Errors in the conduct of systematic reviews of pharmacological interventions for irritable bowel syndrome

OBJECTIVES

Systematic reviews and meta-analyses are integral to evidence-based clinical decision making. Although flawed systematic reviews could compromise optimal decision making, their accuracy has received limited investigation. We assessed conduct of systematic reviews of pharmaceutical interventions for irritable bowel syndrome (IBS).

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews (up to June 2008) to identify and replicate all published systematic reviews and meta-analyses that examined pharmacological interventions for IBS. We identified trials appropriately and inappropriately included according to the investigators' own eligibility criteria and eligible trials the investigators failed to include, and assessed the accuracy of dichotomous data extraction from all truly eligible trials. We conducted meta-analyses of accurate data from all truly eligible trials, and examined the differences between these accurate estimates and those reported by the authors.

RESULTS

The search strategy identified 120 citations, and 13 appeared to be relevant. Five systematic reviews did not extract dichotomous data, leaving eight eligible for inclusion. In five of the eight meta-analyses 13-29% of included trials were ineligible according to investigators' criteria, constituting 8-26% of included patients. Six of the meta-analyses missed 17 separate published eligible trials; 3-11% of eligible patients were, as a result, not included. All eight meta-analyses contained errors in dichotomous data extraction, in 29-100% of truly eligible trials, leading to errors in 15 of 16 reported pooled treatment effects. There was a > or =10% relative difference in treatment effects between the reported and recalculated summary statistic in five (31%) cases, and a change in the statistical significance of the recalculated summary statistic in a further four (25%) cases.

CONCLUSIONS

We found many errors in both application of eligibility criteria and dichotomous data extraction in the eight meta-analyses studied. Independent verification of systematic reviews and meta-analyses may be required for full confidence in their results.

[How can an effective drug to treat irritable bowel syndrome be successfully developed?]

BACKGROUND

Irritable bowel syndrome (IBS) is a prevalent disorder, and although the pharmaceutical industry knows the potential fallout of a successful drug launch in this area, effective drug treatments are rare.

AIM

To give an overview of the main factors interfering with the development of IBS drugs and to provide pertinent methodological indications to improve their investigation in clinical trials.

RESULTS

Developing IBS drugs remains a major challenge, as numerous factors, related or unrelated to the nature of the disease itself, interfere with the demonstration of efficacy : the multiplicity of physiopathological mechanisms, wide variation in symptoms across patients and over time, associated psychological traits and environmental aspects, and a very significant placebo effect. There can be no question of developing drugs to target a single receptor in the hope of thereby impacting the whole range of factors involved in the genesis of IBS symptoms. Drug safety is, moreover, a prime consideration, given that this pathology, while certainly disabling, is not life-threatening. If a significant difference between a new treatment and placebo is to be demonstrated on a clinical trial, inclusion and efficacy criteria and study treatment duration must be predefined very precisely. The primary endpoint is abdominal pain, but the assessment of relief of the patient's symptoms has been also recommended, even if there is as yet no consensus as to its definition. The impact of a new IBS drug on patient's quality of life is an important secondary endpoint.

CONCLUSION

In IBS more, perhaps, than in other pathologies, study design needs very careful consideration if new IBS drug trials are to be conclusive. However, some critical methodological issues (e.g., definite primary endpoint, interpretation of results, and definition of responders) are still unresolved.

Inhibitory effects of Geijigajakyak-Tang on trinitrobenzene sulfonic acid-induced colitis

AIM OF THE STUDY

Water extract of Geijigajakyak-Tang (GJT) consisting of five crude drugs [dried root of P. lactiflora Peony (Paeoniaceae), dried trunk bark of C. cassia Blume (Lauraceae), seed of Z. jujube var. inermis Mill (Rhamnaceae), fresh root of Z. officinale Rocoe (Zingiberaceae) and dried trunk bark of G. uralensis Fish (Leguminosae)] is a folk medicine used for the treatment of chronic colitis. This study was designed to further elucidate the effect of GJT on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats.

MATERIALS AND METHODS

GJT orally given to mice before and after TNBS intoxication, and their clinical and morphological changes, myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels in colon tissues, were evaluated on Day 8 post-TNBS. Furthermore, the effect of six major constituents of individual herbs on ileum smooth muscle contraction and neutrophil chemotaxis was studied.

RESULTS

GJT had a significant anti-inflammatory effect based on clinical and morphologic changes, MPO activity and MDA levels in colon tissues as compared with sham control. GJT and 5 major active constituents of individual herbs, paeoniflorin, cinnamaldehyde, jujuboside A, jujubogenin, and diammonium glycyrhhizinate significantly inhibited neutrophil chemotaxis. GJT significantly inhibited muscle contraction (IC(50); 2.10 +/- 0.11 mg/ml), and 1,8-cineol has the most spasmolytic activity (IC(50); 0.10 +/- 0.03 mg/ml).

CONCLUSION

GJT has significant anti-inflammatory effects on TNBS-induced colitis via inhibitions of smooth muscle contraction and neutrophil chemotaxis.

Recent insights on central processing and psychological processes in functional gastrointestinal disorders

There is increasing evidence for a key role of psychological processes and their central nervous system substrates in functional gastrointestinal disorders, although the exact nature of the relationship remains only partially understood. However, progress in this key area of psychosomatic medicine is rapidly being made. In this review article, we will give an overview of recent advances in understanding the complex mechanisms by which psychological processes and functional gastrointestinal disorder symptoms reciprocally influence each other. Various lines of evidence from different branches of biomedical and psychological science will be discussed, particularly epidemiology, patho- and psychophysiology and functional brain imaging, focusing on the most recent and novel findings. We will conclude this paper with a paragraph on new insights into treatment.

Serotoninergic and non-serotoninergic effects of two tricyclic antidepressants on visceral nociception in a rat model

OBJECTIVE

Tricyclic antidepressants (TCAs) are well established in the treatment of patients with irritable bowel syndrome (IBS). The effects are believed to be linked to serotoninergic antinociceptive properties, but data on the antinociceptive effects of various TCAs with variable serotoninergic and non-serotoninergic properties have not been investigated. The aim of this study was to compare the antinociceptive effects of different TCAs.

MATERIAL AND METHODS

Colorectal distension (CRD) using a barostat device was carried out in rats and the visceromotor response (VMR) to CRD was quantified by abdominal wall electromyography. Prior to CRD, saline (control), amitriptyline (AM), desipramine (DES), reserpine (RES) or a combination of TCAs and RES (AM + RES or DES + RES) was applied intraperitoneally. Serum 5-HT levels were determined using high-performance liquid chromatography (HPLC). RES was used to antagonize the serotoninergic actions of TCAs in order to discriminate between these effects and others.

RESULTS

Both TCAs decreased the VMR compared to placebo. After RES application without TCAs, the VMR was increased compared to controls (6403 microV+/-1772 microV). Co-administration of AM and RES resulted in a modest decrease in VMR (5774 microV+/-1953 microV), while in rats treated with RES and DES the VMR again was significantly lower (3446 microV (+/-1347 microV; p <0.05)). 5-HT levels were higher in TCA pretreated rats than those in controls and significantly lower 5-HT levels were found in all rats pretreated with RES.

CONCLUSIONS

AM and DES have antinociceptive properties while RES is pro-nociceptive. The antinociceptive effects of DES are not abolished by RES pretreatment, while AM only attenuates the pro-nociceptive effects of RES. The non-serotoninergic properties of TCAs substantially contribute to the differences in the antinococeptive effects of various TCAs.

Treatment of irritable bowel syndrome using complementary and alternative medicine

The therapeutic objectives for irritable bowel syndrome (IBS) patients are to improve their functioning in society. Accordingly, recommended management is to develop a logical strategy including a positive diagnosis, consideration of the patient's agenda and emotional state, critical appraisal of the efficacies of various drugs and a graded therapeutic response. Unfortunately, none of the currently available drugs (e.g. antispasmodics, antidiarrheals, osmotics, cathartics, bulking agents, tranquilizers, sedatives) are globally effective in treating all IBS symptoms, and the advanced receptor-targeted drugs are not always successfully and safely marketed. Consequently, more than half of patients may seek complementary and alternative medicine (CAM) to treat the annoying bowel symptoms. Physicians have considered these CAM measures to have an "enhanced placebo effect". For example, many herbal medicine and plant products are globally used to treat IBS, whereas their efficacies are often inconclusive because of small sample sizes, inadequate data analyses and lack of standardized preparations. Meta-analyses do not establish their true efficacy. Acupuncture has long been employed by patients themselves to treat functional gastrointestinal disorders with satisfactory response, but its effect on IBS does not seem to be promising. Peppermint oil, melatonin and clay-like materials are effective in treating some IBS symptoms, while their true pharmacology remains enigmatic. In conclusion, IBS treatment is usually tailored to the individual's manifestations, ranging from reassurance to psychotherapy. Apart from conventional medications, CAM may be considered individually as a supplement or alternative to treat IBS patients that is at least equal in effect to placebo if patients do not exhibit any intolerable or serious side effects.

The placebo response in functional dyspepsia--reanalysis of trial data

Clinical trial data rarely identify factors contributing to the placebo response. We reanalysed the data from the placebo arm (n = 157) of a functional dyspepsia (FD) trial to determine predictors of placebo response including total GIS score, change in GIS score during run-in, type of FD symptoms, duration of illness, age, gender, body mass index (BMI), family occurrence of FD-like symptoms, smoking and alcohol consumption. The same response criteria were applied to the drug arm (n = 158) of the study. Based on the initial 40% response criterion of the study, 35 (22.2%) were classified as placebo responders (PR), whilst 122 (78.8%) were placebo non-responders (PnR). Response rates for the drug arm were 41.1 and 56.9% respectively. PR had significantly lower GIS scores compared to PnR at visit 1 (10.6 +/- 0.6 and 12.3 +/- 0.4, respectively, P = 0.035), but not at visit 2 with study medication dispensing (10.9 +/- 0.5 and 11.3 +/- 0.4). Hence, PR symptoms increased during run-in by 4.2% whilst PnR symptoms decreased by 6.3% (P < 0.005). Gender, age and duration and type of FD symptoms were not different between PR and PnR. Smoking was less prevalent in PR (3%) compared to PnR (21%) (P < 0.025). Increasing the criteria for the placebo response resulted in higher BMI for PR than for PnR (P = 0.035). None of the predictors for placebo response were able to distinguish responders from non-responders to the drug. Variables predicting the PR point towards behavioural and biological mechanism of the PR, operating simultaneously and independently.

Adequate relief in a treatment trial with IBS patients: a prospective assessment

OBJECTIVES

Adequate relief (AR) of irritable bowel syndrome (IBS) symptoms (IBS-AR) has been used as a primary end point in many randomized controlled trials of IBS and is considered by the Rome III committee to be an acceptable primary end point. However, controversy exists on whether baseline severity confounds the effect of the treatment outcome. The aim (1) is to compare a subjective report of IBS-AR with global assessment of improvement (IBS-GAI), change in IBS symptom severity scale (IBS-SSS), and IBS quality of life (IBS-QOL); (2) to explore whether initial IBS symptom severity influences the ability of these outcome measures to detect differences post treatment; and (3) to determine whether psychological symptoms influence the sensitivity of these measures, in a randomized controlled treatment trial.

METHODS

A total of 289 adult IBS patients were recruited to a treatment trial. Baseline IBS-SSS scores were used to classify IBS severity as mild (<175), moderate (175-300), or severe (>300). Questionnaires were completed at baseline and after 3 weeks of treatment with sham acupuncture or wait-list control.

RESULTS

IBS baseline severity (IBS-SSS) significantly affected the proportion of patients who reported IBS-AR at 3 weeks (mild, 70%; moderate, 49.7%; severe, 38.8%) (P<0.05). However, once the patients who reported IBS-AR at baseline (28.0%) were excluded from the analysis, baseline severity no longer affected the proportion of patients reporting IBS-AR. Baseline severity did not have a significant effect on patients reporting moderate or significant improvement on the IBS-GAI (mild, 30%; moderate, 25.3%; severe, 18.8%) (P=NS). Psychological symptoms had no significant correlations with responders after adjusting for baseline severity.

CONCLUSIONS

These data suggest that IBS-AR as an end point is inversely related to baseline symptom severity. However, if patients who report AR at screening were excluded from study participation, baseline symptom severity was no longer confounded with a report of AR at the study end point.

GPs' explanatory models for irritable bowel syndrome: a mismatch with patient models?

BACKGROUND

Inconsistencies in doctors' views about causes and treatment of irritable bowel syndrome (IBS) lead to frustration for doctors and in doctor-patient interactions. Diagnosis by GPs does not correspond well to established diagnostic criteria.

OBJECTIVE

To understand GPs' explanatory models (EMs) and management strategies for IBS.

METHODS

Qualitative, semi-structured interviews with 30 GPs (15 from the UK and 15 from The Netherlands).

RESULTS

Diagnosing IBS in primary care is a complex process, involving symptoms, tests, history and risk calculation. GPs were uncertain about the aetiology of IBS, but often viewed it as a consequence of disordered bowel activity in response to stress, which was viewed as a function of people's responses to their environment. GPs tend to diagnose IBS by exclusion, rather than with formal diagnostic criteria. They endeavoured to present the IBS diagnosis to their patients in a way that they would accept, fearing that many would not be satisfied with a diagnosis that had no apparent physical cause. GPs focused on managing symptoms and reassuring patients. Many GPs felt that patients needed to take the responsibility for managing their IBS and for minimizing its impact on their daily lives. However, the GPs had limited awareness of the extent to which IBS affected their patients' daily lives.

CONCLUSIONS

GPs' diagnostic procedures and EMs for IBS are at odds with patient expectations and current guidelines. Shared discussion of what patients believe to be triggers for symptoms, ways of coping with symptoms and the role of medication may be helpful.

Patients' explanatory models for irritable bowel syndrome: symptoms and treatment more important than explaining aetiology

BACKGROUND

Irritable bowel syndrome (IBS) is a common condition associated with no certain organic cause, though diet and stress are widely implicated. The condition is frustrating for both sufferers and doctors, and there are problems in diagnosing and treating the condition. Eliciting explanatory models (EMs) is a useful tool for understanding how individuals relate to their illnesses and their expectations for treatment, particularly for illnesses with uncertain aetiology like IBS.

OBJECTIVES

To understand the EMs, experiences and expectations for management of patients with IBS.

METHODS

Qualitative, semi-structured interviews were conducted with 51 primary care patients (31 in the UK, 20 in The Netherlands) meeting the Rome II diagnostic criteria for IBS.

RESULTS

Although IBS often had a significant dampening effect on daily life, IBS patients made great efforts not to allow the condition to take over their lives. Triggers of symptoms were more important to patients than understanding the underlying aetiology of IBS. Diet and stress were both recognized as important triggers, but views about which foods were problematic and the extent to which stress was modifiable were inconsistent. Diagnosis and treatment were often a confusing and frustrating process, and patients often expected more diagnostic tests than they were offered before receiving a diagnosis of IBS. However, the often poor outcome of medical interventions does not, in general, appear to have a negative impact on the patient-doctor relationship.

CONCLUSIONS

Clinicians should be aware of the extensive impact of IBS on sufferers' daily life and the frustration that results from repeatedly trying treatments with little effect. Clearly explaining the guidelines for diagnosing IBS and the range of treatment options may help patients to make sense of the diagnostic and treatment processes. The personal EM should be addressed during the consultation with the IBS patient, ensuring that any successive medical interventions match with the patients' disease perception.

Effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome: systematic review and meta-analysis

OBJECTIVE

To determine the effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase, and the Cochrane controlled trials register up to April 2008. Review methods Randomised controlled trials comparing fibre, antispasmodics, and peppermint oil with placebo or no treatment in adults with irritable bowel syndrome were eligible for inclusion. The minimum duration of therapy considered was one week, and studies had to report either a global assessment of cure or improvement in symptoms, or cure of or improvement in abdominal pain, after treatment. A random effects model was used to pool data on symptoms, and the effect of therapy compared with placebo or no treatment was reported as the relative risk (95% confidence interval) of symptoms persisting.

RESULTS

12 studies compared fibre with placebo or no treatment in 591 patients (relative risk of persistent symptoms 0.87, 95% confidence interval 0.76 to 1.00). This effect was limited to ispaghula (0.78, 0.63 to 0.96). Twenty two trials compared antispasmodics with placebo in 1778 patients (0.68, 0.57 to 0.81). Various antispasmodics were studied, but otilonium (four trials, 435 patients, relative risk of persistent symptoms 0.55, 0.31 to 0.97) and hyoscine (three trials, 426 patients, 0.63, 0.51 to 0.78) showed consistent evidence of efficacy. Four trials compared peppermint oil with placebo in 392 patients (0.43, 0.32 to 0.59).

CONCLUSION

Fibre, antispasmodics, and peppermint oil were all more effective than placebo in the treatment of irritable bowel syndrome.

Effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome: systematic review and meta-analysis

OBJECTIVE

To determine the effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase, and the Cochrane controlled trials register up to April 2008. Review methods Randomised controlled trials comparing fibre, antispasmodics, and peppermint oil with placebo or no treatment in adults with irritable bowel syndrome were eligible for inclusion. The minimum duration of therapy considered was one week, and studies had to report either a global assessment of cure or improvement in symptoms, or cure of or improvement in abdominal pain, after treatment. A random effects model was used to pool data on symptoms, and the effect of therapy compared with placebo or no treatment was reported as the relative risk (95% confidence interval) of symptoms persisting.

RESULTS

12 studies compared fibre with placebo or no treatment in 591 patients (relative risk of persistent symptoms 0.87, 95% confidence interval 0.76 to 1.00). This effect was limited to ispaghula (0.78, 0.63 to 0.96). Twenty two trials compared antispasmodics with placebo in 1778 patients (0.68, 0.57 to 0.81). Various antispasmodics were studied, but otilonium (four trials, 435 patients, relative risk of persistent symptoms 0.55, 0.31 to 0.97) and hyoscine (three trials, 426 patients, 0.63, 0.51 to 0.78) showed consistent evidence of efficacy. Four trials compared peppermint oil with placebo in 392 patients (0.43, 0.32 to 0.59).

CONCLUSION

Fibre, antispasmodics, and peppermint oil were all more effective than placebo in the treatment of irritable bowel syndrome.

Evaluation of the Birmingham IBS symptom questionnaire

BACKGROUND

Irritable Bowel Syndrome (IBS) is a chronic/common condition that causes a significant effect on the individual (reduced quality of life), society (time lost off work) and health services. Comparison of studies evaluating the management of IBS has been hindered by the lack of a widely adopted validated symptom score. The aim of this study was to develop and validate a disease specific score to measure the symptoms of patients with IBS.

METHODS

A self-administered 14-item symptom questionnaire (based on Rome II criteria) was mailed to 533 persons included in a prevalence study of IBS. The reliability of each underlying dimension identified was measured by Cronbach's alpha. Validity was assessed by comparing symptom scores with concurrent IBS specific quality of life (QoL) scores. Reproducibility was measured by the test-retest method and responsiveness measured by effect size.

RESULTS

379 (71%) questionnaires were returned. The underlying dimensions identified were pain, diarrhoea and constipation. Cronbach's alpha was 0.74 for pain, 0.90 for diarrhoea and 0.79 for constipation. Pain and diarrhoea dimensions had good external validity (r = -0.3 to -0.6), constipation dimension had moderate external validity (r = -0.2 to -0.3). All dimensions were reproducible (ICCs 0.75 to 0.81). Effect sizes of 0.27 to 0.53 were calculated for those with a reported improvement in symptoms.

CONCLUSION

The Birmingham IBS Symptom Questionnaire has been developed and tested. It has been shown to be suitable for self-completion and acceptable to patients. The questionnaire has 3 internal dimensions which have good reliability, external validity and are responsive to a change in health status.

Efficacy and tolerability of alosetron for the treatment of irritable bowel syndrome in women and men: a meta-analysis of eight randomized, placebo-controlled, 12-week trials

BACKGROUND

Stimulated 5-hydroxytryptamine-3 (5-HT(3)) receptors promote intestinal motility, secretion, and sensation, effects that are related to the known pathophysiology of irritable bowel syndrome (IBS). A previous meta-analysis of 6 randomized controlled trials of the 5-HT(3)-receptor antagonist alosetron found that this agent was associated with global improvement in symptoms, pain, and discomfort in patients with IBS.

OBJECTIVE

This was a meta-analysis of randomized, placebo-controlled trials that evaluated the efficacy and tolerability of alosetron for the management of IBS. It updated and expanded on the previous meta-analysis.

METHODS

PubMed, EMBASE, SCOPUS, Web of Science, and the cochrane central Register of controlled Trials were searched from 1966 through September 2007 for placebo-controlled trials that examined the efficacy and tolerability of alosetron in the management of IBS. The search terms were alosetron, 5-HT, irritable bowel, functional bowel diseases, and irritable colon. No language restriction was applied. The data were analyzed in terms of 2 main outcomes: global improvement in IBS symptoms and adequate relief of IBS pain and discomfort.

RESULTS

Eight multicenter, randomized, placebo-controlled, 12-week clinical trials met the criteria for inclusion in the meta-analysis. The studies included 4,170 patients with IBS (80% female) who were randomized to receive either alosetron or placebo. All patients met the Rome criteria for IBS, and all subtypes of IBS were represented. Most patients had diarrhea-predominant IBS; only 2.6% of patients had constipation-predominant IBS. In the 3 trials included in the analysis of global improvement in symptoms, alosetron was significantly more effective than placebo (relative risk [RR] = 1.60; 95% CI, 1.44-1.76; P <0.001). In the 6 trials included in the analysis of adequate relief of IBS pain and discomfort, there was also a significant difference in favor of alosetron (RR = 1.31; 95% CI, 1.20-1.43; P < 0.001). Analysis of adequate relief of IBS pain and discomfort by sex also indicated significant differences between alosetron and placebo in both sexes (female: RR = 1.34 [95% cI, 1.21-1.48]; male: RR = 1.23 [95% CI, 1.02-1.47]). The analysis of tolerability, which was based on data from 7 studies, found a significant difference between alosetron and placebo (RR = 1.19; 95% cI, 1.07-1.31; P<0.001). The only adverse events that occurred with a significantly higher incidence in those treated with alosetron compared with placebo were constipation in 8 trials (RR = 4.35; 95% CI, 3.01-6.26; P < 0.001) and abdominal pain and discomfort in 5 trials (RR = 1.96; 95% CI, 1.46-2.64; P < 0.001). In the alosetron group, there were 4 cases of ischemic colitis (0.16%) and 2 cases of serious complications of constipation (0.08%); neither of these was reported in the placebo group. Alosetron was not associated with any deaths.

CONCLUSIONS

Alosetron was effective in these men and women with IBS. constipation was the most frequently reported adverse event associated with alosetron therapy. Ischemic colitis and serious complications of constipation were reported in a small number of patients treated with alosetron.

Clinical practice. Irritable bowel syndrome

A 28-year-old woman presents with a 7-month history of recurrent, crampy pain in the left lower abdominal quadrant, bloating with abdominal distention, and frequent, loose stools. She reports having had similar but milder symptoms since childhood. She spends long times in the bathroom because she is worried about uncontrollable discomfort and fecal soiling if she does not completely empty her bowels before leaving the house. She feels anxious and fatigued and is frustrated that her previous physician did not seem to take her distress seriously. Physical examination is unremarkable except for tenderness over the left lower quadrant. How should her case be evaluated and treated?

The role of probiotics in management of irritable bowel syndrome

Irritable bowel syndrome (IBS) affects a significant proportion of the North American population; however, the etiology and pathophysiology of this disease remain poorly understood, and treatment is focused on symptom management. Over the years, research has revealed that the bacterial flora in the human gut interact with the bowel in a complex and dynamic relationship and may be responsible for the induction and progression of some of the pathophysiologic aspects of IBS. Probiotics are nonpathogenic bacteria that benefit the host, and the roles they can play in the bacterio-gut relationship provide hope of a safe treatment that would allow for modulation of IBS disease states. Probiotic treatment for IBS has undergone significant exploration, yet the exact therapeutic effects and doses of these beneficial bacteria remain unclear due to the conflicting nature of available evidence. This review discusses the evidence from randomized controlled trials on probiotic treatment of IBS and presents the current understanding of the mechanisms of action of probiotics as they apply to IBS and provides a plausible explanation for the variability in evidence documented by the various trials under review.