Emerging pharmacological therapies for the irritable bowel syndrome

The irritable bowel syndrome (IBS) is a symptom-based disorder defined by the presence of abdominal pain and altered bowel habits. Clinical presentations of IBS are diverse, with some patients reporting diarrhea, some constipation, and others a mixture of both. Like the varied clinical phenotypes, the pathogenesis of IBS is also diverse. IBS is not a single disease entity, but rather likely consists of several different disease states. This fact has important implications for the choices and efficacy of IBS treatment. This article reviews the IBS drugs that have reached phase II or III clinical trials.     

Management of irritable bowel syndrome]

Management of patients with irritable bowel syndrome (IBS) is based on the positive diagnosis of the symptom complex, limited exclusion of underlying organic disease and institution of a therapeutic trial. As a general approach, physician should establish an effective therapeutic relationship by providing clearly understood explanation to patients of the causes and implications of their symptoms, supported by reassurance and appropriate therapy. Treatment of IBS needs to be individualized, focusing on patients' predominant symptoms. In diarrhea- predominant IBS, loperamide and some antispasmodic agents are efficacious. In constipation-predominant IBS, fiber and bulk laxatives are used empirically, but their efficacy is variable and may aggravate bloating. The 5-HT4 receptor agonist, tegaserod is efficacious in female patients with IBS and constipation. In patients with IBS and abdominal pain, antispasmodics and antidepressants can be used but there is weak evidence of potential benefit. New novel pharmacological agents are being carefully appraised as potential drugs for the future.     

Reizdarmsyndrom

Irritable bowel syndrome (IBS) represents a common, functional gastrointestinal disorder. Predominant symptoms are pain, flatulence, constipation, diarrhea, meteorism and abdominal distension. The diagnosis is made by exclusion of relevant differential diagnoses. Patients are categorized according to defecation problems into diarrhea predominant, constipation predominant and alternating mixed stool behavior. To date, several pathomechanisms of IBS are under discussion. Owing to its heterogeneity, no standard therapy is available and current therapeutic approaches focus on the main symptoms. Dietary fibre, laxatives, spasmolytics, antidepressants, hypnotherapy/psychotherapy and also antibiotics have been reported to be beneficial in the treatment of IBS. Recently, evidence has accumulated that probiotics represent a useful therapeutic approach in the treatment of IBS although effects are strain-specific and individual and cannot be generally assigned to all patients.     

Pharmacologic and complementary and alternative medicine therapies for irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by episodic abdominal pain or discomfort in association with altered bowel habits (diarrhea and/or constipation). Other gastrointestinal symptoms, such as bloating and flatulence, are also common. A variety of factors are believed to play a role in the development of IBS symptoms, including altered bowel motility, visceral hypersensitivity, psychosocial stressors, altered brain-gut interactions, immune activation/low grade inflammation, alterations in the gut microbiome, and genetic factors. In the absence of biomarkers that can distinguish between IBS subgroups on the basis of pathophysiology, treatment of this condition is predicated upon a patient's most bothersome symptoms. In clinical trials, effective therapies have only offered a therapeutic gain over placebos of 7-15%. Evidence based therapies for the global symptoms of constipation predominant IBS (IBS-C) include lubiprostone and tegaserod; evidence based therapies for the global symptoms of diarrhea predominant IBS (IBS-D) include the probiotic Bifidobacter infantis, the nonabsorbable antibiotic rifaximin, and alosetron. Additionally, there is persuasive evidence to suggest that selected antispasmodics and antidepressants are of benefit for the treatment of abdominal pain in IBS patients. Finally, several emerging therapies with novel mechanisms of action are in development. Complementary and alternative medicine therapies including probiotics, herbal therapies and acupuncture are gaining popularity among IBS sufferers, although concerns regarding manufacturing standards and the paucity of high quality efficacy and safety data remain.     

不同药物治疗肠易激综合征的临床疗效

背景:肠易激综合征(IBS)是消化内科常见疾病之一,但目前所用药物尚不能对所有IBS症状有疗效。目的:分析不同药物对不同类型IBS的临床疗效。方法:136例便秘型IBS患者随机分为西沙必利或莫沙必利治疗组(A组)和西沙必利或莫沙必利+乳果糖治疗组(B组);72例腹泻型IBS患者随机分为匹维溴铵治疗组(C组)和马来酸曲美布汀治疗组(D组),分别观察治疗1周、1个月和3个月时的疗效。结果:A组1周、1个月和3个月时的总有效率分别为29.8％、25.3％和19.0％,而B组分别为69.2％、51.9％和41.2％,均显著高于A组(P<0.005、P<0.005和P<0.01)。C组1周、1个月和3个月时的总有效率分别为90.9％、67.7％和61.3％,而D组分别为79.5％、51.4％和31.4％,C组3个月时的总有效率显著高于D组(P<0.05)。各组的疗效在3个月时均有所降低,但B组和C组的总有效率仍较高。结论:单用西沙必利或莫沙必利治疗便秘型IBS疗效有限,加用乳果糖可提高疗效。匹维溴铵和马来酸曲美布汀对腹泻型IBS的近期疗效较好。     

Genetic epidemiology of irritable bowel syndrome

Irritable bowel syndrome(IBS) is the most common functional gastrointestinal disorder characterized by presence of abdominal pain or discomfort associated with altered bowel habits. It has three main subtypes- constipation predominant IBS(C-IBS),diarrhea predominant IBS(D-IBS) and IBS with mixed featuresof both diarrhea as well as constipation(M-IBS). Its pathophysiology and underlying mechanisms remain elusive. It is traditionally believed that IBS is a result of multiple factors including hypersensitivity of the bowel,altered bowel motility,inflammation and stress. Initial studies have shown familial aggregation of IBS suggesting shared genetic or environmental factors. Twin studies of IBS from different parts of world have shown higher concordance rates among monozygotic twins than dizygotic twins,and thus suggesting a genetic component to this disorder. Multiple studies have tried to link single-nucleotide polymorphisms(SNPs) to IBS but there is little evidence that these SNPs are functional. Various molecules have been studied and investigated by the researchers. Serotonin,a known neurotransmitter and a local hormone in the enteric nervous system,has been most extensively explored. At this time,the underlying gene pathways,genes and functional variants linked with IBS remain unknown and the promise of genetically-determined risk prediction and personalize medicine remain unfulfilled. However,molecular biological technologies continue to evolve rapidly and genetic investigations offer much promise in the intervention,treatment and prevention of IBS.     

Current gut-directed therapies for irritable bowel syndrome

Opinion statement Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder that can present with a wide array of symptoms that make treatment difficult. Current therapies are directed at relieving symptoms of abdominal pain or discomfort, bloating, constipation, and diarrhea. Pharmacologic agents used to treat IBS-associated pain include myorelaxants, peppermint oil, and peripherally acting opiates. Dicyclomine and hyoscyamine, the two myorelaxants available in the United States, have not been proven effective in reducing abdominal pain in patients with IBS. The efficacy of peppermint oil is debated, but methodological problems with existing studies preclude definitive judgment. Loperamide is ineffective for relief of abdominal pain. For IBS patients with excessive abdominal bloating, a small number of studies suggest that bacterial eradication with gut-directed antibiotics and bacterial reconstitution with nonpathogenic probiotics may reduce flatulence. For constipation-predominant (C-IBS) symptoms, current treatment options include fiber supplementation, polyethylene glycol, and tegaserod. Soluble fibers (ispaghula, calcium polycarbophil, psyllium) are more effective than insoluble fibers (wheat bran, corn fiber) in alleviating global symptoms and relieving constipation, although fiber in general has marginal benefit in treatment of overall IBS symptoms. Polyethylene glycol increases bowel frequency in chronic constipation, but its overall efficacy against IBS is unclear. Tegaserod, a 5-HT₄ agonist, demonstrates superiority over placebo in improving bowel frequency and stool consistency and alleviating abdominal pain and bloating in women with C-IBS. Overall global symptoms are modestly improved with tegaserod when compared with placebo. Additional agents under investigation for C-IBS include the ClC₂ chloride channel opener lubiprostone, μ-opioid receptor antagonist alvimopan, and 5-HT₄ agonist renzapride. For diarrhea-predominant (D-IBS) symptoms, available therapies include loperamide, alosetron, and clonidine. Alosetron, a 5-HT₃ antagonist, is superior to placebo for reducing bowel frequency, improving stool consistency, and relieving abdominal pain in women with D-IBS. However, alosetron is available under a restricted license because of concerns for ischemic colitis and severe constipation necessitating colectomy. Clonidine may be helpful in alleviating global symptoms for D-IBS patients.     

Treatment options in irritable bowel syndrome

The irritable bowel syndrome (IBS) is part of the spectrum of functional bowel disorders characterised by a diverse consortium of abdominal symptoms including abdominal pain, altered bowel function (bowel frequency and/or constipation), bloating, abdominal distension, the sensation of incomplete evacuation and the increased passage of mucus. It is not surprising therefore that no single, unifying mechanism has as yet been put forward to explain symptom production in IBS. The currently favoured model includes both central and end-organ components which may be combined to create an integrated hypothesis incorporating psychological factors (stress, distress, affective disorder) with end-organ dysfunction (motility disorder, visceral hypersensitivity) possibly aggravated by sub-clinical inflammation as a residuum of an intestinal infection. There is currently no universally effective therapy for IBS. Standard therapy generally involves a symptom-directed approach; anti-diarrhoeal agents for bowel frequency, soluble fibre or laxatives for constipation and smooth muscle relaxants and anti-spasmodics for pain. New drug development has focused predominantly on agents that modify the effects of 5-hydroxytryptamine (5-HT) in the gut, principally the 5-HT(3) receptor antagonists for painful diarrhoea predominant IBS and 5-HT(4) agonists for constipation predominant IBS. More speculative new therapeutic approaches include anti-inflammatory agents, antibiotics, probiotics, antagonists of CCK1 receptors, tachykinins and other novel neuronal receptors.     

Update in the therapeutic management of irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a remarkably frequent disorder that leads to relevant impairment in patients' quality of life. Four mechanisms are involved in the pathogenesis of IBS: altered intestinal motility; increased visceral sensitivity; disturbed intestinal reflexes (intrinsic and extrinsic), and psychological disorders. The close relationship between the central nervous system and the enteric nervous system (the brain-gut axis) is the basis of the actual research on IBS therapy. It is conceivable that in the near future a better understanding of IBS pathophysiology will help us to tailor treatment for different IBS patients. At the moment, the subclassification of the diverse patterns of symptomatology allows the adjustment of treatments for IBS according to the clinical predominance of each patient. Dietary modifications like fiber supplementation, antidiarrheal agents and antispasmodic drugs are the basis of the current treatment of IBS and depend on the predominant symptom (constipation, diarrhea or pain, respectively). If severe pain is present, antidepressant agents are an appropriate alternative. However, the scientific evidence supporting this current therapeutic approach is limited. Visceral analgesics and serotonin agonists and antagonists may play an important therapeutic role in the near future. However, it is not likely that one single treatment will help every IBS patient and many of them will need a more complex approach with multidisciplinary therapy (diet, psychotherapy, medications).     

Irritable bowel syndrome consulters in Zhejiang province： The symptoms pattern, predominant bowel habit subgroups and quality of life

AIM: To investigate the pattern of symptoms, predominant bowel habits and quality of life (QOL) by the Chinese version of the SF-36 in irritable bowel syndrome (IBS) consulters in Zhejiang province. METHODS: From January 2001 to January 2002, 662 Roma Ⅱ criteria-positive IBS patients were enrolled by gastroenterologists in 10 hospitals from Digestive Disease Center of Zhejiang (DDCZ). Patients were classified into constipation predominant IBS (IBS-C), diarrhea predominant IBS (IBS-D) and alternating constipation and diarrhea IBS (IBS-A) according to the predominant bowel habits. All patients were evaluated for the demographic checklists, IBS bowel symptoms, extra-colonic symptoms, and QOL by Chinese version of the SF-36 questionnaire. RESULTS: (1) Besides abdominal pain, the predominant colonic symptoms were in order of altered stool form, abnormalities of stool passage, abdominal distension and passage of mucus in IBS patients. Also, IBS subjects reported generalized body discomfort and psychosocial problems including dyspeptic symptoms, poor appetite, heartburn, headache, back pain, difficulty with urination, fatigue, anxiety and depression. (2) IBS-C and IBS-A are more common among female patients, whereas male patients experienced more cases of IBS-D. In regards to the IBS symptoms, there were significant differences among IBS subgroups. Abdominal pain (frequency ≥2 days per week and duration ≥1 hour per day) was frequent in IBS-A patients (P=0.010 and 0.027, respectively), IBS-D patients more frequently experienced the passage of mucus, dyspeptic symptoms and anxiety (P=0.000, 0.014 and 0.015, respectively). (3) IBS patients experienced significant impairment in QOL, decrements in QOL were most pronounced in vitality, general health, mental health, and bodily pain. Compared with the general population (adjusted for gender and age), IBS patients scored significantly lower on all SF-scales (P&lt;0.001), except for physical function scale (P=0.149). (4) QOL was impaired in all subgroups, particularly in scales of vitality, general health and mental health. Compared with IBS-D, QOL in IBS-C scored significantly lower on physical function, role physical, general health, role emotional, and mental health scales (P=-0.037, 0.040, 0.039, 0.005 and 0.026, respectively). CONCLUSION: Besides colonic symptoms, IBS could cause generalized body discomfort and psychosocial problems. The IBS subgroups based on predominant bowel habits are helpful to identify clinical distinction of the IBS. QOL is significantly impaired in IBS patients. The Chinese version of the SF-36 health survey scales may be a useful measurement of IBS patients.     

Irritable bowel syndrome: Pathogenesis,diagnosis, treatment,and evidence-based medicine

Irritable bowel syndrome(IBS)is a chronic and debilitating functional gastrointestinal disorder that affects9%-23%of the population across the world.The percentage of patients seeking health care related to IBS approaches 12%in primary care practices and is by far the largest subgroup seen in gastroenterology clinics.It has been well documented that these patients exhibit a poorer quality of life and utilize the health care system to a greater degree than patients without this diagnosis.The pathophysiology of IBS is not clear.Many theories have been put forward,but the exact cause of IBS is still uncertain.According to the updated ROMEⅢcriteria,IBS is a clinical diagnosis and presents as one of the three predominant subtypes:(1)IBS with constipation(IBS-C);(2)IBS with diarrhea(IBS-D);and(3)mixed IBS(IBS-M);former ROME definitions refer to IBS-M as alternating IBS(IBS-A).Across the IBS subtypes,the presentation of symptoms may vary among patients and change over time.Patients report the most distressing symptoms to be abdominal pain,straining,myalgias,urgency,bloating and feelings of serious illness.The complexity and diversity of IBS presentation makes treatment difficult.Although there are reviews and guidelines for treating IBS,they focus on the efficacy of medications for IBS symptoms usinghigh-priority endpoints,leaving those of lower priority largely unreported.Therefore,the aim of this review is to provide a comprehensive evidence-based review of the diagnosis,pathogenesis and treatment to guide clinicians diagnosing and treating their patients.     

Lubiprostone for chronic idiopathic constipation and irritable bowel syndrome with constipation

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

Serotonin transporter gene polymorphism in irritable bowel syndrome

OBJECTIVES: Serotonin is a key mediator of intestinal peristalsis, and after it is secreted, it is effectively cleansed from the neuronal gap by means of a high affinity substance called serotonin transporter (SERT), which depends on the Na+ and Cl- ions localized in the presynaptic neuronal membranes. The aim of this study was to investigate SERT polymorphism in patients with irritable bowel syndrome (IBS). METHODS: SERT gene polymorphism was assessed by polymerase chain reaction on DNA chains obtained from leukocytes in serum samples from 54 patients diagnosed with IBS and 91 healthy subjects. The polymorphism of two regions (variable number tandem repeats and the SERT gene-linked polymorphic region [5-HTTLPR]) of SERT was assessed. RESULTS: SERT polymorphisms were found to be similar in healthy subjects and IBS patients (p > 0.05). IBS patients were divided into three groups: diarrhea predominant (n = 18), constipation predominant (n = 26), and alternating diarrhea and constipation (n = 10). These groups were compared with respect to gene polymorphism, and it was found that the 5-HTTLPR allele S/S genotype occurred with greater frequency in the constipation predominant group than in the other two subgroups (p < 0.05), and L/S genotype frequency in the diarrhea predominant group was higher than those in the constipation and control groups. CONCLUSIONS: No relationship was found between IBS and SERT gene polymorphism. It is conceivable that the presence of the S/S genotype in IBS patients carries an increased risk of the constipation predominant type of IBS, whereas the presence of the 5-HTTLPR allele L/S genotype carries an increased risk of the diarrhea predominant type.     

肠易激综合征的治疗进展

人群中肠易激综合征的患病率较高，但其发病机制目前尚未完全清楚。腹痛、腹泻、便秘和其他不适症状常使肠易激综合征患者的生活质量降低且可伴有焦虑。因此肠易激综合征的治疗目的主要是减轻症状，改善患者的生活质量．目前治疗主要是针对胃肠运动、感觉以及对中枢神经系统的调节，特别是针对肠道受体调节剂的药物层出不穷。     

广州市居民肠易激综合征及功能性便秘的流行病学调查

目的：探讨广州市居民肠易激综合征（IBS）及功能性便秘的流行病学情况。方法：采用整群随机抽样法抽取广州市居民2892人进行问卷调查,同时问卷普通内科及消化专科门诊连续病例各1006及495例。结果：（1）广州市居民IBS的患病率为5．6％,普通内科门诊及消化专科门诊中IBS所的比例分别为10．1％、34．3％,IBS女性患病率显著高于男性,男女比例为1：1．51（P＝0．27）,年龄对IBS的患病率无显著影响,IBS患者的就诊率为22．4％,男女就诊率差异无显著性。IBS各亚型构成比为：腹泻主导型占63．2％,便秘主导型占27．0％,男女就诊率鞠显著性,IBS各亚型构成比为：腹泻主导型占63．2％,便秘主导型占27．0％,其他型占9．8％,（2）广州市居民功能性便秘的患病率为3．0％,普通内科门诊及消化专科门诊中所占的比例分别为5．4％及4．8％。男性患病率显著低于女性,男女比例为1：1．877。随着年龄的增加,功能性便秘的患病率升高,社区人群中功能性便秘的就诊率为17．6％,男女差异无显著性。结论：广州市居民IBS及功能性便秘的患病率低于国外报道水平。     

Irritable bowel syndrome: Epidemiology,diagnosis and treatment: An update for health‐care practitioners

Irritable bowel syndrome (IBS), a chronic gastrointestinal disorder, affects from 3–20% of the US population, depending on sociocultural and comorbid factors. IBS is characterized by a symptom complex of abdominal pain and abnormal bowel habits that present as diarrhea or constipation, and general physical weakness in the absence of abnormal morphological, histological or inflammatory markers. The main diagnostic Rome III criteria as established by international professional organizations are based on exclusion criteria and the occurrence and rate of symptoms. Because the pathophysiology and causes of IBS are poorly understood, treatment approaches are mainly focused on symptom management to maintain everyday functioning and improve quality of life for persons with IBS. The mainstay of intervention is pharmacological treatment with antispasmodics and antidiarrheals for diarrhea, prokinetics and high‐fiber diets for constipation, and supportive therapy with low‐dose antidepressants to normalize gastrointestinal motility. Other interventions include lifestyle and dietary changes, psychotherapy, herbal therapies and acupuncture. The purpose of this review is to critically assess benefits and risks of current treatment approaches as well as promising complementary and alternative therapies.     

The serotonin signaling system: from basic understanding to drug development for functional GI disorders

Serotonin is an important gastrointestinal signaling molecule. It is a paracrine messenger utilized by enterochromaffin (EC) cells, which function as sensory transducers. Serotonin activates intrinsic and extrinsic primary afferent neurons to, respectively, initiate peristaltic and secretory reflexes and to transmit information to the central nervous system. Serotonin is also a neurotransmitter utilized by a system of long descending myenteric interneurons. Serotonin is synthesized through the actions of 2 different tryptophan hydroxylases, TpH1 and TpH2, which are found, respectively, in EC cells and neurons. Serotonin is inactivated by the serotonin reuptake transporter (SERT)-mediated uptake into enterocytes or neurons. The presence of many serotonin receptor subtypes enables selective drugs to be designed to therapeutically modulate gastrointestinal motility, secretion, and sensation. Current examples include tegaserod, a 5-HT(4) partial agonist, which has been approved for treatment of irritable bowel syndrome (IBS) with constipation in women and for chronic constipation in men and women. The 5-HT(3) antagonists, granisetron and ondansetron, are useful in combating the nausea associated with cancer chemotherapy, and alosetron is employed in the treatment of IBS with diarrhea. Serotonergic signaling abnormalities have also been putatively implicated in the pathogenesis of functional bowel diseases. Other compounds, for which efficacy has not been rigorously established, but which may have value, include tricyclic antidepressants and serotonin selective reuptake inhibitors to combat IBS, and 5-HT(1) agonists, which enhance gastric accommodation, to treat functional dyspepsia. The initial success encountered with serotonergic agents holds promise for newer and more potent insights and therapies of brain-gut disorders.     

Subtypes of irritable bowel syndrome on Rome III criteria: a multicenter study

Background and Aim: The aim of this study was to explore the distribution and clinical characteristics of four subtypes of irritable bowel syndrome (IBS) based on Rome III criteria in Chinese. Methods: A total of 754 consecutive IBS outpatients from three tertiary hospitals in China were included. Diagnostic criteria were based on Rome II or Rome III. Results: Among 754 outpatients, 510 (67.6%) patients met the Rome II criteria, 735 (97.5%) patients met the Rome III criteria and 492 (65.3%) patients met both sets of criteria. Among 735 patients who met the Rome III criteria, 66.3% had IBS with diarrhea (IBS‐D), 14.7% had IBS with constipation (IBS‐C), 4.2% had mixed IBS (IBS‐M) and 14.8% had unsubtyped IBS (IBS‐U). Most of the IBS‐D, IBS‐C and IBS‐M patients based on the Rome III criteria matched the diarrhea‐predominant IBS, constipation‐predominant IBS and alternating IBS based on the Rome II criteria, respectively. Among IBS‐U patients, 57.0%, 33.3% and 9.7% had constipation‐predominant IBS, diarrhea‐predominant IBS and alternating IBS, respectively. For IBS‐M, the frequencies of bowel movements were stable in 48.4% patients and variable in 51.6% patients. Defecation urgency and straining were most frequent in IBS‐M and least frequent in IBS‐U patients than other subtypes. About 77.2% of IBS‐U patients had abnormal stool frequency (< 3 times/week or > 3 times/day). Conclusion: The Rome III criteria are more sensitive and practical in diagnosing IBS. IBS‐D is the most frequent subtype, which is followed by IBS‐U, IBS‐C and IBS‐M. IBS‐U is a new subtype, which warrants further studies.     

Prevalence of irritable bowel syndrome in Hong Kong

BACKGROUND AND AIMS: As part of a public education program, the Hong Kong Society of Gastrointestinal Motility studied the prevalence of irritable bowel syndrome (IBS) in the community, which was based on the recently published Rome II criteria. The distribution of diarrhea or constipation-predominant IBS subtypes, the prevalence of bowel symptoms and the predictors of health-care seeking were also studied. METHODS: Among 1797 randomly selected respondents, 1000 successful telephone interviews (56%) were conducted from August 2000 to December 2000, using a validated questionnaire in Chinese that looked into demographic data and various bowel symptoms during the past year. RESULTS: The 12-month prevalence of IBS as defined by the Rome II criteria in Hong Kong was 6.6%. The female to male ratio was 1.3:1, but this ratio was the same in the control group. The distribution of IBS patients into diarrhea predominant, constipation predominant, and non-specific subtypes was 27, 17 and 56%, respectively. The predominant symptom in the IBS group was pain (54.5%), followed by urgency (15%), abdominal distension (15%) and diarrhea (11%). Forty-seven percent of IBS patients sought medical attention and only 21% of them knew that they had IBS. Moderate to severe pain severity (odds ratio 3.7, 95% CI 1.02-13) and mucus in stool (odds ratio 3.57, 95% CI 1.18-10.7) were associated with health-care seeking in univariate analysis. The prevalence of bowel symptoms such as urgency, straining, feeling of incomplete defecation, mucus in stool and abdominal distension ranged from 11 to 41%. CONCLUSION: The prevalence of IBS in Hong Kong was 6.6%, and the female to male ratio was similar to the control group. The majority was of non-specific IBS subtype. Gross underdiagnosis (21%) by Western practitioners was noted.     

盐酸屈他维林治疗肠易激综合征的多中心临床试验

背景:肠易激综合征(IBS)是一种常见的慢性功能性肠病,严重影响患者的生活质量,现有治疗药物多数疗效欠佳。目的:观察盐酸屈他维林对IBS的疗效和安全性。方法:采用前瞻性、自身对照、多中心试验设计。217例IBS患者接受盐酸屈他维林片80 mg tid口服治疗,疗程2周。每天记录腹痛以及排便不尽感、排便费力、排便急迫感等伴随症状及其严重程度,同时记录排便次数和粪便性状。结果:经盐酸屈他维林治疗2周,IBS患者的周平均腹痛评分较治疗前显著减低(0.66±0.59对1.42±0.42,P=0.0000),总有效率达77.9%;便秘型IBS(IBS-C)患者的一周日平均排便次数较治疗前显著增加(0.8+0.3对0.6±0.4,P=0.0004),腹泻型IBS(IBS-D)患者则较治疗前显著减低(1.6+0.8对2.8±1.2,P=0.0000),两组患者的粪便性状以及排便不尽感、排便费力、排便急迫感等亦分别有不同程度的改善。试验中未发生严重不良事件。结论:盐酸屈他维林能有效且安全地治疗各亚型IBS。