Food intolerance and the irritable bowel syndrome

Psychological burden of food allergy

One fifth of the population report adverse reactions to food. Reasons for these symptoms are heterogeneous, varying from food allergy, food intolerance, irritable bowel syndrome to somatoform or other mental disorders. Literature reveals a large discrepancy between truly diagnosed food allergy and reports of food allergy symptoms by care seekers. In most studies currently available the characterization of patient groups is incomplete, because they did not distinguish between immunologic reactions and other kinds of food reactions. In analysing these adverse reactions, a thorough physical and psychological diagnostic approach is important. In our qualitative review, we present those diagnostic measures that are evidenced-based as well as clinically useful, and discuss the various psychological dimensions of adverse reactions to food. It is important to acknowledge the complex interplay between body and mind: Adults and children suffering from food allergy show impaired quality of life and a higher level of stress and anxiety. Pavlovian conditioning of adverse reactions plays an important role in maintaining symptoms. The role of personality, mood, or anxiety in food reactions is debatable. Somatoform disorders ought to be identified early to avoid lengthy and frustrating investigations. A future task will be to improve diagnostic algorithms, to describe psychological aspects in clearly characterised patient subgroups, and to develop strategies for an optimized management of the various types of adverse reactions to food.

Comorbidity and use of health-care services among irritable bowel syndrome sufferers

OBJECTIVE

Patients suffering from irritable bowel syndrome (IBS) have more somatic and psychiatric comorbidity and use more health-care services for comorbid conditions than do other patients. Little is known about the frequency of comorbid symptoms among IBS sufferers in the general population and their influence on use of health-care facilities. The objective of this study was to compare the frequency of somatic and psychiatric symptoms between IBS sufferers and controls in the general population, and to study how comorbidity rates are distributed among consulters and non-consulters and how they predict the use of health care-services.

MATERIAL AND METHODS

By means of a questionnaire sent to 5000 randomly selected adults IBS was identified according to the Rome II criteria. The questionnaire also covered upper GI symptoms, non-GI somatic symptoms, depression and anxiety. A logistic regression analysis with 26 variables was carried out to determine the independent predictors of health-care seeking for GI and non-GI complaints.

RESULTS

The response rate was 73% and prevalence of IBS 5.1% (95% CI 4.4-5.8%). Dyspeptic symptoms, somatic extra-GI symptoms and psychiatric symptoms were reported by 45%, 69% and 51% of IBS sufferers, respectively, and 6%, 35% and 27%, of controls, respectively. Visiting a physician because of GI complaints was associated with disturbing abdominal symptoms, but not with depression or anxiety. Of the present GI conditions, only dyspeptic symptoms were associated with an increased consultation rate also for non-GI complaints.

CONCLUSIONS

In the general population, both IBS consulters and non-consulters demonstrate high rates of comorbidity. Seeking health care for abdominal complaints is associated with abdominal symptoms rather than psychiatric comorbidity.

Nutritional aspects in patients with functional gastrointestinal disorders and motor dysfunction in the gut. Working team report of the Swedish Motility Group (SMoG)

In reviews regarding the management of patients with functional gastrointestinal disorders and motility disturbances within the gut nutritional aspects and dietary advice is often put forward as being of great importance. However, there are relatively few high-quality, interventional studies in the literature supporting an important role for general dietary advice to improve symptoms in these patients. Nutritional supplementation to patients with malnutrition due to severe dysfunction of the gastrointestinal tract is of course less controversial, even though different views on how this should be performed exist. The content of this article is based on presentations given by the authors during the second meeting of the Swedish Motility Group held in Gothenburg in March 2005, and aims to give an overview on the role of dietary advice and nutritional supplementation to patients with gastrointestinal dysfunction of different severity.

Treating irritable bowel syndrome with a food elimination diet followed by food challenge and probiotics

OBJECTIVE

In Irritable Bowel Syndrome, the gut-associated immune system may be up-regulated resulting in immune complex production, low-grade inflammation, loss of Class I bacteria, and translocation of inflammatory mediators and macromolecules outside of the GI lumen. Since food intolerance may be one of the reasons for this upregulation, our goal was to investigate the role of food intolerance in IBS patients.

METHODS

In this open label pilot study, we enrolled 20 patients with IBS by Rome II criteria (15 women, ages 24-81) who had failed standard medical therapies in a tertiary care GI clinic. Baseline serum IgE and IgG food and mold panels, and comprehensive stool analysis (CSA) were performed. Breath-hydrogen testing and IBS Quality-of-Life (QOL) questionnaires were obtained. Patients underwent food elimination diets based on the results of food and mold panels followed by controlled food challenge. Probiotics were also introduced. Repeat testing was performed at 6-months. We followed up with this cohort at 1 year after trial completion to assess the reported intervention and for placebo effect.

RESULTS

Baseline abnormalities were identified on serum IgG food and mold panels in 100% of the study subjects with significant improvement after food elimination and rotation diet (p < 0.05). Significant improvements were seen in stool frequency (p < 0.05), pain (p < 0.05), and IBS-QOL scores (p < 0.0001). Imbalances of beneficial flora and dysbiotic flora were identified in 100% of subjects by CSA. There was a trend to improvement of beneficial flora after treatment but no change in dysbiotic flora. The 1-year follow up demonstrated significant continued adherence to the food rotation diet (4.00 +/- 1.45), minimal symptomatic problems with IBS (4.00 +/- 1.17), and perception of control over IBS (4.15 +/- 1.23). The continued use of probiotics was considered less helpful (3.40 +/- 1.60).

CONCLUSION

These data demonstrate that identifying and appropriately addressing food sensitivity in IBS patients not previously responding to standard therapy results in a sustained clinical response and impacts on overall well being and quality of life in this challenging entity.

Treatment of irritable bowel syndrome in outpatients with inflammatory bowel disease using a food and beverage intolerance, food and beverage avoidance diet

Irritable bowel syndrome (IBS) in the outpatient with chronic inflammatory bowel disease (IBD) is a difficult but important challenge to recognize and treat. It is very helpful to have effective treatment approaches for IBS that are practical and use minimal medications. Because of the underlying chronic inflammation in IBD, IBS symptoms occur with increased frequency and severity, secondary to increased hypersensitivity to foods and beverages that stimulate the gastrointestinal tract. This paper discusses how to treat IBS in the IBD outpatient, with emphasis on using a food and beverage intolerance, avoidance diet. The adverse effects of many foods and beverages are amount dependent and can be delayed, additive, and cumulative. The specific types of foods and beverages that can induce IBS symptoms include milk and milk containing products; caffeine containing products; alcoholic beverages; fruits; fruit juices; spices; seasonings; diet beverages; diet foods; diet candies; diet gum; fast foods; condiments; fried foods; fatty foods; multigrain breads; sourdough breads; bagels; salads; salad dressings; vegetables; beans; red meats; gravies; spaghetti sauce; stews; nuts; popcorn; high fiber; and cookies, crackers, pretzels, cakes, and pies. The types of foods and beverages that are better tolerated include water; rice; plain pasta or noodles; baked or broiled potatoes; white breads; plain fish, chicken, turkey, or ham; eggs; dry cereals; soy or rice based products; peas; applesauce; cantaloupe; watermelon; fruit cocktail; margarine; jams; jellies; and peanut butter. Handouts that were developed based upon what worsens or helps IBS symptoms in patients are included to help patients learn which foods and beverages to avoid and which are better tolerated.

Irritable Bowel Syndrome: A Practical Review

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

Is there a role of food allergy in irritable bowel syndrome and functional dyspepsia? A systematic review

A significant proportion of adults believe they suffer from food allergy, and 20-65% of patients with irritable bowel syndrome (IBS) attribute their symptoms to something in food that activates an abnormal response. This systematic review evaluates the role of food allergy in aetiology and management of these disorders. Activation of gastrointestinal mucosal immune system may be one of the causative factors in the pathogenesis of functional dyspepsia and IBS. This activation may result from effects of bacterial infection or other luminal factors including commensal microbial flora and food antigens. Some studies have reported on the role of food allergy in IBS; only one epidemiological study on functional dyspepsia and food allergy has been published. The mechanism by which food activates mucosal immune system is uncertain, but food specific IgE and IgG4 appeared to mediate the hypersensitivity reaction in a subgroup of IBS patients. Exclusion diets based on skin prick test, RAST for IgE or IgG4, hypoallergic diet and clinical trials with oral disodium cromoglycate have been conducted, and some success has been reported in a subset of IBS patients. Further well-controlled studies are needed to establish whether food allergy plays a role in the pathophysiology of functional dyspepsia and IBS.

Perceived food intolerance in subjects with irritable bowel syndrome-- etiology, prevalence and consequences

OBJECTIVES

This study estimates the prevalence of perceived food intolerance and its consequences in subjects with irritable bowel syndrome (IBS), evaluates the utility of common tests for food intolerance, studies the relation between perceived food intolerance and other disorders, and discusses the etiology.

DESIGN

Cross-sectional study.

SETTING

National health survey.

SUBJECTS

A selection of the population (n=11,078) in Oppland county, Norway, was invited to a health screening, and a sample of subjects with IBS were included in the study.

INTERVENTIONS

A medical history of food intolerance, musculoskeletal pain, mood disorders and abdominal complaints was taken, and tests were performed for food allergy and malabsorption. A dietician evaluated the dietary habits of the subjects.

RESULTS

Out of 4,622 subjects with adequately filled-in questionnaires, 84 were included in the study, 59 (70%) had symptoms related to intake of food, 62% limited or excluded food items from the diet and 12% had an inadequate diet. The mean numbers of food items related to symptoms and the number of foods limited or excluded from the diet were 4.8 and 2.5, respectively. There were no associations between the tests for food allergy and malabsorption and perceived food intolerance. Perceived food intolerance was unrelated to musculoskeletal pain and mood disorders.

CONCLUSIONS

Perceived food intolerance is a common problem with significant nutritional consequences in a population with IBS. The uselessness of current antibody tests and tests for malabsorption and the lack of correlation to psychiatric co-morbidity make the etiology obscure.

Food intolerance and skin prick test in treated and untreated irritable bowel syndrome

AIM: To correlate the clinical features of treated and untreated patients with irritable bowel syndrome (IBS) to the results of skin prick test (SPT) for food and inhalant allergens.

METHODS: We recruited 105 subjects to form three different target groups: treated group (n = 44) undergoing treatment for IBS, untreated group (n = 31) meeting the Rome II criteria without treatment for IBS, control group (n = 30) with no IBS symptoms.

RESULTS: SPT results were different among the three groups in which SPT was positive in 17 (38.6%) treated patients, in 5 (16.1%) untreated patients and in 1 (3.3%) control (P < 0.01). The number of positive SPTs was greater in the IBS group than in the control group (P < 0.001). The number of positive food SPTs was higher in the treated IBS group than in the untreated IBS group (P = 0.03).

CONCLUSION: Positive food SPT is higher in IBS patients than in controls.

Detection of inflammatory markers in stools from patients with irritable bowel syndrome and collagenous colitis

OBJECTIVE

Irritable bowel syndrome (IBS) and collagenous colitis (CC) share chronically recurring symptoms of altered bowel habits associated with abdominal pain or discomfort. The aims of the present study were to investigate whether inflammatory markers could be detected in faeces from patients with IBS and CC, and to elucidate whether such analyses could be used as non-invasive tools to distinguish between these disorders.

MATERIAL AND METHODS

Stool samples were obtained from 18 patients with CC, 46 patients with IBS and 20 healthy controls (HC). Eosinophil protein X (EPX), myeloperoxidase (MPO), tryptase, interleukin-1 beta (IL-1beta) and tumour necrosis factor alpha (TNFalpha) were measured in supernatants from processed faeces using immunoassays.

RESULTS

EPX levels were enhanced in faeces from CC patients (median 3.8 microg/g (0.47-16.2)) compared to patients with IBS (0.44 microg/g (0.25-1.8)), p<0.001, and HC (0.46 microg/g (0.21-1.3)), p<0.001. In addition, MPO was increased in CC patients (11.7 microg/g (2.0-124)) compared to IBS patients (1.7 microg/g (0.81-5.2)), p<0.01, and HC (2.5 microg/g (1.1-6.3)), p<0.05. Tryptase was found in 9/18 patients with CC, 6/46 with IBS and 1/19 HC. IL-1beta was only enhanced in 2/11 CC patients and TNFalpha was not detected in any sample.

CONCLUSIONS

Increased levels of EPX, MPO and tryptase were observed in stools from collagenous colitis patients, whereas the levels in IBS patients did not differ from healthy controls. Our data suggest that faecal markers could be used as part of the clinical work-up to determine which patients should be biopsied and evaluated for collagenous colitis.

Nutrition and motility disorders

The purpose of this article is to give an overview of the relation between feeding and gastrointestinal symptoms and complaints, and to review different motility disorders that have implications for food intake. We also report the consequences for nutrition state and the evidence-based principles of dietary modification in patients with motility disorders.

Towards a better understanding of abdominal bloating and distension in functional gastrointestinal disorders

Abdominal bloating is an extremely common symptom affecting up to 96% of patients with functional gastrointestinal disorders and even 30% of the general population. To date bloating has often been viewed as being synonymous with an actual increase in abdominal girth, but recent evidence suggests that this is not necessarily the case. This review examines the relationship between the symptom of bloating and the physical sign of abdominal distension, as well as examining the epidemiology, pathophysiology and treatment options available for this debilitating aspect of the functional gastrointestinal disorders. Pathophysiological mechanisms explored include psychological factors, intestinal gas accumulation, fluid retention, food intolerance and malabsorption of sugars, weakness of abdominal musculature, and altered sensorimotor function. Treatment options are currently rather limited but include dietary changes, pharmacological approaches, probiotics and hypnotherapy.

Food-specific serum IgG4 and IgE titers to common food antigens in irritable bowel syndrome

INTRODUCTION

Food hypersensitivity is a common perception among irritable bowel syndrome (IBS) patients. Data from dietary elimination and food challenge studies support an etiopathological role of diet in IBS, but there are no well-established tests to identify food hypersensitivity.

AIM

To compare IgG4 and IgE titers to common food antigens in IBS and controls.

METHOD

One hundred and eight IBS [52 diarrhea-predominant (D-IBS); 32 constipation-predominant (C-IBS); 24 alternating (Alt-IBS)], and 43 controls were included in the study. IgG4 and IgE titers and skin prick testing (SPT) to 16 common foods including milk, eggs, cheese, wheat, rice, potatoes, chicken, beef, pork, lamb, fish, shrimps, soya bean, yeast, tomatoes, and peanuts were measured.

RESULTS

IBS had significantly higher IgG4 titers (mug/L) to wheat (395 IQR +/- 1,011 vs 0 IQR +/- 285, p < 0.001), beef (1,079 IQR +/- 930 vs 617 IQR +/- 435, p < 0.001), pork (481 IQR +/- 379 vs 258 IQR +/- 496, p < 0.001), and lamb (241 IQR +/- 460 vs 167 IQR +/- 232, p= 0.009) compared to controls. These differences were maintained across all three subgroups. The antibody titers to potatoes, rice, fish, chicken, yeast, tomato, and shrimps were not significantly different. No significant difference in IgE titers was observed between IBS and controls. SPT was positive for only a single antigen in 5 of 56 patients tested with the same panel of foods. No correlation was seen between the pattern of elevated IgG4 antibody titers and patients' symptoms.

CONCLUSION

Serum IgG4 antibodies to common foods like wheat, beef, pork, and lamb are elevated in IBS patients. In keeping with the observation in other atopic conditions, this finding suggests the possibility of a similar pathophysiological role for IgG4 antibodies in IBS.

Potential future therapies for irritable bowel syndrome: will disease modifying therapy as opposed to symptomatic control become a reality?

Irritable bowel syndrome can remit spontaneously, implying cure is possible. Predictors of good prognosis include a short history, acute onset(possibly postinfective origin), absence of psychological disorders, and resolution of chronic life stressors. Possible-disease modifying treatments with long-lasting effects include diet and anti-inflammatory and psychological treatments. Dietary modifications, which often involve excluding dairy and wheat products, are successful in some patients. Anti-inflammatory treatments have been subjected to one RCT in postinfective IBS without benefit. Probiotics may have benefit in altering bacterial flora and as anti-inflammatory agents, but further trials are needed before they can be recommended. Psychological treatments may produce long-lasting responses. Relaxation therapy appears to have a nonspecific benefit. Psychotherapy has been shown to have long-term benefit and is particularly acceptable to, and effective for, those with overt psychological distress. Hypnotherapy has been shown to be effective in randomized placebo controlled trials and has a sustained effect.

Do interventions which reduce colonic bacterial fermentation improve symptoms of irritable bowel syndrome?

Abnormal fermentation may be an important factor in irritable bowel syndrome (IBS). Gastroenteritis or antibiotic therapy may damage the colonic microflora, leading to increased fermentation and the accumulation of gas. Gas excretion may be measured by whole-body calorimetry but there has only been one such study on IBS to date. We aimed to assess the relationship between IBS symptoms and fermentation rates in IBS. A purpose-built, 1.4-m3, whole-body calorimeter was used to assess excretion of H2 and CH4 in IBS subjects while consuming a standard diet and, again, after open randomization on either the standard diet together with the antibiotic metronidazole or a fiber-free diet to reduce fermentation. Metronidazole significantly reduced the 24-hr excretion of hydrogen (median value compared to the control group, 397 vs 230 ml/24 hr) and total gas (H2 + CH4; 671 vs 422 ml/min) and the maximum rate of gas excretion (1.6 vs 0.8 ml/min), as did a no-fiber polymeric diet (hydrogen, 418 vs 176 ml/min; total gas, 564 vs 205 ml/min; maximum rate of gas excretion, 1.35 vs 0.45 ml/min), with a significant improvement in abdominal symptoms. IBS may be associated with rapid excretion of gaseous products of fermentation, whose reduction may improve symptoms.

The epidemiological aspects of irritable bowel syndrome in Southeastern Anatolia: a stratified randomised community-based study

Even though studies on the epidemiology of the irritable bowel syndrome (IBS) are increasing day by day, epidemiological data are still unknown in many regions. Our objective was to determine the IBS prevalence, factors associated with this prevalence and probable risk groups in Southeastern Anatolia. The total population in the target region is approximately 6 million. A total of 3000 people (1521 females and 1479 males) randomly selected by stratified cluster sampling were interviewed face-to-face by using a questionnaire comprising demographic features and the Rome II criteria which also included probable risk factors and questions related with Bristol scale stool form. The statistical analysis was performed by using a package program called EPI INFO 2000. IBS prevalence was 10.2% according to the Rome II criteria in our region. Six hundred and twenty-five of 3000 subjects had gastrointestinal symptoms in the last 3 months. IBS rate was higher in women (12.4%) than in men (8.0%), and married subjects had higher IBS rates (11.6%) than singles (6.7%). Those differences were statistically significant (p = 0.000 for both). It was most common in the 35-54-year age group. No difference was observed in terms of settlement (rural/urban), age group, education and occupation. History of abortion in women increased the IBS risk by 1.8 times (p = 0.000 Crude odds ratios = 1.8 (1.3-2.6) 95% confidence intervals). Of the IBS patients, 48.1% had characteristics of diarrhoea-predominance, 38.9% constipation-predominance while 13.0% had none. There was a significant relation between dominant stool form and Bristol scale stool form. IBS prevalence is 10.2% in the first community-based study carried out in this specific subject in Southeastern Anatolia. The dominance of middle age and females remained significant.

The perceived effect of various foods and beverages on stool consistency

AIM

Some people believe that chocolate and other foods or beverages may cause constipation. This study was undertaken to quantify the effect of potentially constipating foods and beverages on apparently healthy and constipated populations of German individuals.

METHODS

A questionnaire asking for the effect of certain foods and beverages on stool form (perceived consistency) was answered by 200 healthy controls, 122 patients with chronic constipation, and 766 patients with irritable bowel syndrome with constipation (IBS-C).

RESULTS

Patients with constipation or IBS-C reported altered stool form after food and beverage consumption more often than controls (controls 42.5% vs constipation 52.0% vs IBS-C 57.0%, P < 0.001). Controls experienced hardening of stools less often and experienced softening more often than either constipation or IBS-C patients. When patients were asked which foods or beverages caused constipation (open ended question), chocolate was most frequently mentioned, followed by white bread and bananas. The results of systematic questioning yielded chocolate (48-64% of respondents), bananas (29-48%), and black tea (14-24%) as constipating, while prunes (41-52%), coffee (14-24%), wine (8-30%), beer (14-24%), and smoking (42-70% in those who smoked) were considered stool softeners.

CONCLUSION

Several foodstuffs may exert an effect on stool consistency. Chocolate, bananas and black tea are perceived to cause constipation, while prunes are perceived to soften stools in many people. Coffee, wine and beer were perceived to soften stools in a minority of people. Cigarettes are perceived to soften stools by about half of the smokers.

Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial

BACKGROUND

Patients with irritable bowel syndrome (IBS) often feel they have some form of dietary intolerance and frequently try exclusion diets. Tests attempting to predict food sensitivity in IBS have been disappointing but none has utilised IgG antibodies.

AIMS

To assess the therapeutic potential of dietary elimination based on the presence of IgG antibodies to food.

PATIENTS

A total of 150 outpatients with IBS were randomised to receive, for three months, either a diet excluding all foods to which they had raised IgG antibodies (enzyme linked immunosorbant assay test) or a sham diet excluding the same number of foods but not those to which they had antibodies.

METHODS

Primary outcome measures were change in IBS symptom severity and global rating scores. Non-colonic symptomatology, quality of life, and anxiety/depression were secondary outcomes. Intention to treat analysis was undertaken using a generalised linear model.

RESULTS

After 12 weeks, the true diet resulted in a 10% greater reduction in symptom score than the sham diet (mean difference 39 (95% confidence intervals (CI) 5-72); p = 0.024) with this value increasing to 26% in fully compliant patients (difference 98 (95% CI 52-144); p<0.001). Global rating also significantly improved in the true diet group as a whole (p = 0.048, NNT = 9) and even more in compliant patients (p = 0.006, NNT = 2.5). All other outcomes showed trends favouring the true diet. Relaxing the diet led to a 24% greater deterioration in symptoms in those on the true diet (difference 52 (95% CI 18-88); p = 0.003).

CONCLUSION

Food elimination based on IgG antibodies may be effective in reducing IBS symptoms and is worthy of further biomedical research.

Intraepithelial lymphocytes in the villous tip: do they indicate potential coeliac disease?

BACKGROUND

The counting of intraepithelial lymphocytes (IELs) in the villous tips of architecturally normal small bowel biopsy specimens was proposed as a method to measure mucosal infiltration in gluten sensitive patients.

AIMS

To apply this straightforward method in duodenal biopsy specimens from patients affected by potential coeliac disease (PCD) to verify whether it can discriminate these patients from controls.

METHODS

Paraffin wax embedded duodenal sections from 11 patients affected by PCD were stained with an antihuman CD3 antibody. Sections from 19 patients affected by treated coeliac disease (TCD) and 17 patients in whom coeliac disease was excluded were stained with the same antibody to serve as controls. The slides were examined blindly. IELs/20 enterocytes in five randomly chosen villous tips were counted. Patients affected by PCD were all on a gluten containing diet. They had an architecturally normal duodenal mucosa and were positive for endomysial antibody. Both TCD and non-coeliac controls were negative for endomysial antibody.

RESULTS

The mean villous tip IEL scores were 4.6 (SD, 1.5; range, 1.4-7.8) in non-coeliac controls, 7.9 (SD, 4.0; range, 2.0-18.6) in TCD, and 9.2 (SD, 4.7; range, 5.8-21.8) in patients with PCD. The difference between PCD and non-coeliac controls was significant.

CONCLUSIONS

This is a very simple and sufficiently reliable method to count IELs. In patients with an architecturally normal duodenal mucosa, the IEL count in villous tips helps to distinguish between patients with PCD and non-coeliac controls.

Diagnosis and therapy of irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common gut functional diseases, affecting 10-20% of people worldwide. Although most patients do not seek medical help, the disease accounts for huge costs for both patients and health-care systems and worsens significantly patients' quality of life. Diagnosis is based on the identification of symptoms according to Manning, Rome I and Rome II criteria and exclusion of alarm indicators. IBS symptoms overlap with those of coeliac disease, lactose intolerance, food allergies and bile salt malabsorption. The treatment of IBS is centred on an excellent doctor-patient relationship along with drugs targeting the predominant symptom, especially during exacerbations. Current pharmacological remedies are unsatisfactory due to the high number of patients complaining of lack of response and/or symptom recurrence. Although useful in some IBS patients, the validity of psychotherapy deserves further investigation. A wide array of potentially useful drugs are currently under consideration in pre-clinical trials. A better understanding of the pathogenetic mechanisms underlying IBS may help to develop more effective drugs for this disease.

Celiac disease serology in irritable bowel syndrome and dyspepsia: a population-based case-control study

OBJECTIVE

To determine whether undiagnosed celiac disease is associated with irritable bowel syndrome (IBS) or dyspepsia in the community.

SUBJECTS AND METHODS

A self-report bowel disease questionnaire was mailed to a random sample of Olmsted County, Minnesota, residents aged 20 to 50 years. All respondents who reported symptoms of dyspepsia or IBS (cases) and all respondents without notable gastrointestinal symptoms (controls) were invited to participate (260 eligible subjects; 150 [58%] were studied). Each respondent was examined by a physician, and the medical records of each were reviewed (3 subjects did not meet the criteria for dyspepsia or IBS at the time of the physician interview). Serum was obtained to measure antiendomysial antibodies and tissue transglutaminase (TTg) IgA antibodies using validated assays.

RESULTS

A total of 34 subjects had dyspepsia (20 had ulcerlike dyspepsia), 50 had IBS (19 had diarrhea-predominant IBS), and 15 met criteria for both dyspepsia and IBS; 78 were asymptomatic healthy controls. The overall prevalence of positive TTg serology was 4% (95% confidence interval [CI], 1.5%-8.5%). The number of subjects who were seropositive for TTg was 2 of 34 (5.9%) with dyspepsia (95% CI, 0.7%-19.7%), 2 of 50 (4.0%) with IBS (95% CI, 0.5%-13.7%), and 2 of 78 (2.6%) of asymptomatic controls (95% CI, 03%-9.0%) (P = .64 IBS vs controls; P = .58 dyspepsia vs controls). No subjects had positive antiendomysial antibodies.

CONCLUSION

In this community, celiac disease did not explain the presence of either IBS or dyspepsia.

N/A

N/A

Irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common 'functional' gastrointestinal disorders accounting for 3% of all primary care consultations, with a strong female predominance. Although most of the literature comes from Western industrialized societies, when it has been looked for, this disorder appears to be equally common in the Third World. It is characterized by chronic abdominal pain or discomfort associated with disordered bowel habit and visceral hypersensitivity. Anxiety and somatization are more common in IBS than in the general population and may encourage consultation; however, they correlate poorly with symptoms. Bacterial gastroenteritis may be followed by the development of IBS in 5-10% of patients, depending on the severity of initial illness and prior anxiety or depression. The Rome criteria allow reliable diagnosis provided that there are no 'alarm' features which mandate further investigation. Microscopic colitis and bile salt malabsorption can easily be mistaken for IBS, as can chronic infestations or infections which should be considered, while recognizing that these are extremely uncommon in westernized societies. Some patients respond to exclusion diets as lactose and wheat intolerance are common. Others with prominent anxiety and/or depression respond to psychotherapy or antidepressants. Diarrhoeal symptoms respond to loperamide and 5HT3 receptor antagonists, while constipation responds to 5HT4 agonists. Antispasmodics may have limited benefit in treating pain. Low-dose tricyclic antidepressants are also helpful in alleviating pain and anxiety, even in those without obvious psychiatric disorders. If diagnostic criteria are met, then once diagnosed, new diagnoses rarely appear.

Breath testing to evaluate lactose intolerance in irritable bowel syndrome correlates with lactulose testing and may not reflect true lactose malabsorption

OBJECTIVES

An increased prevalence of lactose intolerance is seen in irritable bowel syndrome (IBS). Recently, we demonstrated a high prevalence of abnormal lactulose breath test results in IBS suggesting bacterial overgrowth. Because symptoms of lactose intolerance result from bacterial fermentation, the purpose of this study was to determine whether an abnormal lactose breath test is reflective of malabsorption or early presentation to bacteria.

METHODS

Subjects with diarrhea-predominant IBS were enrolled. On day 1, subjects underwent a lactulose breath test after an overnight fast. Within 1 wk, subjects returned after fasting for a lactose breath test with simultaneous blood glucose measurements every 15 min to complete a lactose tolerance test (LTT). Symptoms were evaluated 3 h after lactose administration.

RESULTS

Twenty subjects completed the study. One subject inadvertently received dextrose through the intravenous and was excluded. Of the remaining 19 subjects, three (16%) had an abnormal LTT suggesting malabsorption. In all, 10 subjects (53%) had an abnormal lactose breath test, 14 (74%) had an abnormal lactulose breath test, and 11 (58%) had symptoms after lactose administration. The agreement with symptoms was moderate (kappa = 0.47) and fair (kappa = 0.24) when compared to the lactose breath test and LTT, respectively. There was a fair correlation between lactose breath test and LTT (kappa = 0.29). However, lactose breath test hydrogen levels >166 ppm were universally predictive of abnormal LTT. Finally, a significant correlation was seen between the hydrogen production on lactose and lactulose breath test (r = 0.56, p = 0.01).

CONCLUSIONS

Lactose breath testing in IBS subjects does not seem to reflect malabsorption; it may be an indicator of abnormal lactulose breath test, suggesting bacterial overgrowth.

Food Intolerance: Dietary Treatments in Functional Bowel Disorders

Currently, there is little convincing scientific evidence from well-designed trials to support the role of dietary modification or exclusions in irritable bowel syndrome (IBS). Similarly, there is an absence of conclusive data linking any dietary components directly to the pathogenesis of IBS. The role of diet, as a single modality, is unlikely to play a major role in treating IBS. Dietary modifications should be viewed as a valuable part of a multicomponent management approach in combination with other strategies such as lifestyle, behavioral, and pharmacologic therapy.

Treatment of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is an extremely common cause of consultation, and at present is diagnosed on the basis of symptoms and a few simple exclusion tests. Exclusion diets can be successful, but many patients have already attempted and failed such treatments before consulting. Anxiety and somatization may be an important driver of consultation. Patients' concerns should be understood and addressed. Those with prominent psychiatric disease may benefit from psychotherapy. Hypnotherapy benefits symptoms in those without psychologic disturbance, but its availability is limited. Antidepressants are effective in improving both mood and IBS symptoms globally, and the evidence is particularly good for tricyclic antidepressants. Although antispasmodics are currently the most commonly prescribed drugs, most responses (75%) are due to the placebo effect and not specific to the drug. Bulk laxatives such as ispaghula can increase stool frequency and help pain, but bloating may be aggravated. Loperamide is effective treatment for urgency and loose stools, but less effective for bloating and pain. 5-HT(3) antagonists such as alosetron improve urgency, stool consistency, and pain in diarrhea-predominant-IBS. The 5-HT(4) agonist tegaserod shows modest benefit in constipation-predominant IBS, improving stool frequency, consistency, and bloating as well as global improvement. There are many new drugs, such as cholecystokinin, neurokinin, and corticotropin receptor antagonists, in development.

Irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common diagnoses made in the primary care setting and is responsible for up to 40% of referrals to gastroenterologists. Approximately 70% of persons who meet the diagnostic criteria for IBS do not seek health care, and the remaining account for 12% of visits to primary care providers. IBS is a functional bowel disordered comprising abdominal pain associated with defecation or a change in bowel habit with features of disordered defecation and distension in the absence of any demonstrable abnormality. The diagnosis is based on clinical findings and the exclusion of other disorders. New pharmaceutical agents are available to treat the underlying disorder; however, the treatment of IBS still involves a comprehensive, multicomponent approach that includes medical management of dominant symptoms, dietary modifications, and, possibly, psychotherapy.

Irritable bowel syndrome: unravelling the mysteries

The irritable bowel syndrome (IBS) has long been the Achilles heel of gastroenterology. IBS is a syndrome of abdominal pain accompanied by a change in bowel habit for which no cause can be discovered on standard investigations. The diagnosis thus depends on the exclusion of more serious pathology. As IBS is the most common chronic gut disorder seen in the Western World, accounting for as many as 50% of referrals to gastrointestinal outpatients, the cost of repeated negative investigations is alarming (Talley et al, 1995).

Effect of Lactobacillus plantarum 299v on colonic fermentation and symptoms of irritable bowel syndrome

A number of recent clinical trials have promoted the use of probiotic bacteria as a treatment for irritable bowel syndrome (IBS). The recent demonstration of abnormal colonic fermentation in some patients with this condition provides an opportunity for the objective assessment of the therapeutic value of these bacteria. This study was designed to investigate the effects of Lactobacillus plantarum 299V on colonic fermentation. We conducted a double-blind, placebo-controlled, cross-over, four-week trial of Lactobacillus plantarum 299V in 12 previously untreated patients with IBS. Symptoms were assessed daily by a validated composite score and fermentation by 24-hr indirect calorimetry in a 1.4-m3 canopy followed by breath hydrogen determination for 3 hr after 20 ml of lactulose. On placebo, the median symptom score was 8.5 [6.25-11.25 interquartile range (IQR)], the median maximum rate of gas production was 0.55 ml/min (0.4-1.1 IQR), and the median hydrogen production was 189.7 ml/24 hr (118.3-291.1 IQR). On Lactobacillus plantarum 299V the median symptom score was 8 (6.75-13.5 IQR), the median maximum rate of gas production 0.92 ml/min (0.45-1.5 IQR), and the median hydrogen production 208.2 ml/24 hr (146-350.9 IQR). There was no significant difference. Breath hydrogen excretion after lactulose was reduced by the probiotic (median at 120 min, 6 ppm; placebo, 17 ppm; P = 0.019). In conclusion, Lactobacillus plantarum 299V in this study did not appear to alter colonic fermentation or improve symptoms in patients with the irritable bowel syndrome.

A review of the role of the gut microflora in irritable bowel syndrome and the effects of probiotics

Irritable bowel syndrome (IBS) is a multi-factorial gastrointestinal condition affecting 8-22 % of the population with a higher prevalence in women and accounting for 20-50 % of referrals to gastroenterology clinics. It is characterised by abdominal pain, excessive flatus, variable bowel habit and abdominal bloating for which there is no evidence of detectable organic disease. Suggested aetiologies include gut motility and psychological disorders, psychophysiological phenomena and colonic malfermentation. The faecal microflora in IBS has been shown to be abnormal with higher numbers of facultative organisms and low numbers of lactobacilli and bifidobacteria. Although there is no evidence of food allergy in IBS, food intolerance has been identified and exclusion diets are beneficial to many IBS patients. Food intolerance may be due to abnormal fermentation of food residues in the colon, as a result of disruption of the normal flora. The role of probiotics in IBS has not been clearly defined. Some studies have shown improvements in pain and flatulence in response to probiotic administration, whilst others have shown no symptomatic improvement. It is possible that the future role of probiotics in IBS will lie in prevention, rather than cure.

Clinical perspectives, mechanisms, diagnosis and management of irritable bowel syndrome

This consensus document reviews the current status of the epidemiology, social impact, patient quality of life, pathophysiology, diagnosis and treatment of irritable bowel syndrome. Current evidence suggests that two major mechanisms may interact in irritable bowel syndrome: altered gastrointestinal motility and increased sensitivity of the intestine. However, other factors, such as psychosocial factors, intake of food and prior infection, may contribute to its development. Management of patients is based on a positive diagnosis of the symptom complex, careful history and physical examination to exclude 'red flags' as risk factors for organic disease, and, if indicated, investigations to exclude other disorders. Therapeutic choices include dietary fibre for constipation, opioid agents for diarrhoea and low-dose antidepressants or infrequent use of antispasmodics for pain, although the evidence basis for efficacy is limited or in some cases absent. Psychotherapy and hypnotherapy are the subject of ongoing study. Treatment should be tailored to patient needs and fears. Novel therapies are emerging, and drugs acting on serotonin receptors have proven efficacy and a scientific rationale and, if approved, should be useful in the overall management of patients with irritable bowel syndrome. Patient and physician education, early identification of psychosocial issues and better therapies are important strategies to reduce the suffering and societal cost of irritable bowel syndrome.

Evaluation of hydrogen excretion after lactulose administration as a screening test for causes of irritable bowel syndrome

OBJECTIVE

To determine whether it is possible to separate cases of irritable bowel syndrome associated with excess total hydrogen production (as a surrogate of colonic fermentation; these patients may be offered an exclusion diet as treatment) from other causes of irritable bowel syndrome by determining the amount of hydrogen excreted on patients' breath after oral administration of lactulose.

DESIGN

Comparison of 24-hour hydrogen excretion and breath hydrogen following lactulose in untreated patients fulfilling the Rome criteria for irritable bowel syndrome, normal controls and irritable bowel syndrome patients who had previously failed to improve on an exclusion diet.

METHODS

Colonic fermentation was measured by indirect calorimetry over 24 h. Immediately after calorimetry, the patients who were fasting received 20 g lactulose; end-expiratory breath samples were then collected every 30 min for 3 h. Hydrogen concentrations were determined by an electro-chemical cell.

RESULTS

The total 24-hour excretion of hydrogen was significantly greater in the irritable bowel syndrome group (median 333.7 ml/24 h, interquartile range 234.7-445.67) compared to the normal volunteers (median 203.1 ml/24 h, interquartile range 131.4-256; P = 0.002) or the failed-diet group (median 204.5 ml/24 h, interquartile range 111.35-289.13; P = 0.015). No difference was detected in breath excretion of hydrogen following lactulose in any group.

CONCLUSION

Total hydrogen production over 24 h is increased in some patients with irritable bowel syndrome who may respond to exclusion diets. However, this sub-group of patients cannot be identified by measuring breath-hydrogen excretion after lactulose.

Diet in the irritable bowel syndrome

Patients with irritable bowel syndrome (IBS) often request dietary recommendations. They must eat, and they want to know what to eat. Present national guidelines recommend dietary treatment with fiber for IBS patients with constipation. Diet recommendations are made based on symptoms. There may be different dietary recommendations for constipation, diarrhea, and pain or bloating. This article reviews the relationship of foods to IBS and issues of food intolerances and hypersensitivities, and recommendations for diet therapy. The role of dietary fiber, both soluble and insoluble, is reviewed. Although there are few studies to substantiate exact diets, broad dietary plans are recommended for the different symptoms of IBS. In addition, the recent literature on probiotics and prebiotics pertinent to IBS is reviewed.

Irritable bowel syndrome and nonspecific diarrhea in infancy and childhood--relationship with juice carbohydrate malabsorption

Lactose intolerance and malabsorbed carbohydrate present in some fruitjuice may trigger symptoms commonly seen in irritable bowel syndrome. In a two-site study, 28 subjects 9 months to 18 years old (mean 6.9 +/- 5.9 years) with significant intake of apple juice or pear nectar (> 6 oz a day) with the diagnoses of irritable bowel syndrome, functional abdominal pain, or chronic nonspecific diarrhea were recruited. Breath hydrogen tolerance tests utilizing lactose, sucrose, and apple juice in the amount they typically consumed were positive in 32%, 0%, and 50%, respectively. Subjects were asked to refrain from the ingestion ofjuice for 1 month: 13 of the 28 (46%) subjects improved while 15 (54%) showed no change in their symptoms. In fact, none consuming 6 to 12 oz of apple or pear juice daily improved, 27% of those consuming 12 to 16 oz improved, and 91% of those consuming > 16 oz improved (P < 0.02). Subjects were then given comparable amounts of white grape juice for 1 year. The initial symptoms did not recur in any of the subjects who initially responded to the juice-free diet. Of the 15 subjects who did not respond to the juice-free diet, seven became asymptomatic. Overall, 20 subjects (71%) were asymptomatic, and eight (29%) had no change in their symptoms. Some individuals with irritable bowel syndrome have their symptoms based on their malabsorption of carbohydrates present in apple juice and pear nectar and may improve with adequate choices of fruit juice such as changing to white grape juice.

Food intolerance and allergy in gastrointestinal disorders

Approximately 60 tonnes of food passes through the gastrointestinal tract in an average lifetime. With a surface area second only to the respiratory tract, it is surprising that adverse reactions to food do not occur more frequently.

Celiac disease-like abnormalities in a subgroup of patients with irritable bowel syndrome

BACKGROUND & AIMS

Abdominal symptoms in the absence of mucosal abnormalities are features of both the irritable bowel syndrome (IBS) and latent/potential celiac disease (cd). To identify a possible subgroup of IBS patients with latent/potential cd, surrogate markers of cd were investigated in IBS patients.

METHODS

IBS patients suffering from diarrhea (n = 102), and patients with active cd (n = 10), treated cd (n = 26), and latent cd (n = 5) were included in the study. We measured serum immunoglobulin (Ig) A against gliadin and tissue-transglutaminase, and IgA and IgM against gliadin, tissue-transglutaminase (intestinal cd-associated antibodies), and the dietary proteins beta-lactoglobulin and ovalbumin in duodenal aspirate by enzyme-linked immunosorbent assay. Intraepithelial lymphocytes (IELs) were counted in histology sections, and the expression of HLA-DQ2 (A1*0501/B1*0201) was investigated by polymerase chain reaction. In 26 IBS patients, the effect of 6 months of gluten withdrawal was examined.

RESULTS

Most cd patients expressed HLA-DQ2 and had increased intestinal cd-associated antibodies, whereas cd-associated serum IgA and IEL counts were increased in active cd in contrast to treated or latent cd. In IBS patients, 35% were HLA-DQ2-positive, 23% had increased IEL counts, and 0% and 30% had increased cd-associated antibodies in serum and duodenal aspirate, respectively. Furthermore, stool frequency and intestinal IgA decreased significantly under a gluten-free diet in the subgroups of HLA-DQ2-positive and intestinal antibody-positive IBS patients when compared with IBS patients without these markers.

CONCLUSIONS

HLA-DQ2 expression and increased intestinal cd-associated antibodies are markers that can identify latent/potential cd in a subgroup of IBS patients who consequently appear to profit from a gluten-free diet.

Nutritional issues in irritable bowel syndrome

Food products have variously been reported as causing, perpetuating or treating irritable bowel syndrome. The evidence for this is reviewed with regard to recent studies investigating symptom reporting, mono- and disaccharide malabsorption and probiotics. The development of objective measures remains an urgent priority because of the high placebo response to any dietary intervention in irritable bowel syndrome.

Diarrhea- and Constipation-predominant Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) has a reputation for being hard to treat, trivial, and often psychologic in origin. Furthermore, there currently appears to be almost more of a stigma attached to being diagnosed as having IBS than a depressive illness. Thus, it is not surprising that patients with this syndrome become distressed by the attitudes they encounter, particularly as we now know that this condition can substantially impair one's quality of life. The problem with effective management is that there is no "standard treatment" and therapy has to be targeted to the symptoms of the individual patient. This frequently proves to be time consuming and also may involve some degree of trial and error. However, when all the issues surrounding IBS are addressed in a sympathetic and positive manner, these patients can be surprisingly rewarding to treat.