Role of alimentation in irritable bowel syndrome

BACKGROUND: Different food items are made responsible for irritable bowel syndrome (IBS) symptoms, but the physiopathology of IBS remains unclear. AIMS: During a meeting in Nice, France, experts of the European Working Team of the IBiS Club discussed selected data regarding the relationships between alimentation, food items (including fibers) and IBS symptoms. METHODS/RESULTS: Food allergy remains a difficult diagnosis, but medical and general history, presence of general symptoms such as skin rash, and hypersensitivity tests may help in achieving a positive diagnosis. On the other hand, food intolerance is more confusing because of the subjectivity of the relationship between ingestion of certain foods and the appearance of clinical symptoms. Different food items which are commonly implicated in adverse reactions mimicking IBS were found to be stimulants for the gut, suggesting that patients with predominant diarrhea IBS have to be carefully questioned about consumption of different kinds of food (i.e., coffee, alcohol, chewing gum, soft drinks) and not only on lactose ingestion. Gas production is discussed on the basis of retention of intestinal gas as well as on malabsorption of fermentable substrates. The role of a large amount of this kind of substrate reaching the colon is suggested as a potential mechanism of IBS-type symptoms in overeating patients. Regarding the role of fiber in IBS, the expert group concluded that fibers are not inert substances and that they could trigger pain or bloating in some IBS patients. CONCLUSION: Despite numerous reviews on this subject, it is very difficult to give general dietary advice to IBS patients, but dieteticians may have a positive role in managing such patients.     

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 RomeⅡcriteria 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.     

Dietary and allergic associations with rheumatoid arthritis: Self-report of 704 patients

A survey of 704 rheumatoid arthritis (RA) patients was performed to analyze responses of patients reporting favorable or unfavorable effects of specific foods on clinical status. Overall, 28% of patients reported some association between a specific food and clinical status. Patients reporting food associations tended to report higher levels of allergies and family history of allergies, but did not differ importantly in clinical status or demographic variables from patients reporting no associations of foods and clinical status. These data suggest that a subset of RA patients might have food sensitivity as a component of clinical activity, but most patients find no associations between foods and clinical status.     

Irritable bowel syndrome in primary care: the patients' and doctors' views on symptoms, etiology and management.

BACKGROUND: To facilitate the development of clinical guidelines and to direct future irritable bowel syndrome (IBS) research, insight into the perceptions of patients and general practitioners (GPs) regarding IBS is required. OBJECTIVES: To compare patients' and GPs' views on the symptomatology, etiology and treatment of IBS. METHODS: One hundred forty-two IBS patients and 100 GPs were requested to complete a structured questionnaire. RESULTS: The response rates of the patients and GPs were 80% and 47%, respectively. Abdominal pain and bloating were considered to be the most bothersome symptoms in IBS, by both patients and GPs. Although all patients were diagnosed by their GP as having IBS, and 62% met the Manning criteria, only 18% fulfilled the Rome II criteria for IBS. Patients consider food intolerance and GPs regard lack of fibre as the main etiologic dietary factor. Many IBS patients expect a diagnostic work-up, but GPs generally restrict this to elderly patients. GPs start IBS management with dietary advice (94%), counselling (77%) and drug therapy (55%). Patients expect reassurance (47%) and drug treatment (37%), but dietary interventions are less appreciated (9%). CONCLUSIONS: Patients and GPs have different perceptions of the efficacy of diagnostic and dietary interventions in IBS. GPs should explore the patients expectations and incorporate these in their approach to IBS patients.     

Food-related gastrointestinal symptoms in the irritable bowel syndrome

BACKGROUND/AIMS: Postprandial symptoms are common in patients with irritable bowel syndrome (IBS). However, existing studies have come to different conclusions about the role of food in the pathophysiology of IBS. We explored the prevalence of subjective food-related gastrointestinal (GI) symptoms and its relationship to clinical characteristics and psychological factors in IBS. METHODS: 330 patients with IBS and 80 healthy volunteers completed a food questionnaire developed for this study. The subjects graded their subjective symptoms after 35 different foods and a food score was obtained by adding the item scores. The relationship between subjective food-related GI symptoms and referral status, IBS subgroup (predominant bowel pattern), sex, anxiety, depression and body mass index (BMI) was estimated. RESULTS: In 209 (63%) of the patients the GI symptoms were related to meals. Gas problems and abdominal pain were the most frequently reported symptoms. Foods rich in carbohydrates, as well as fatty food, coffee, alcohol and hot spices were most frequently reported to cause symptoms. The food score was higher in patients than in controls (p < 0.0001). In the IBS group higher scores were observed in patients with anxiety (p = 0.005), and females (p < 0.001), but the results were unrelated to IBS subgroup, referral status or BMI. The BMI did not differ between groups. CONCLUSION: A majority of IBS patients consider their symptoms to be related to meals. Especially foods rich in carbohydrates and fat cause problems. Nevertheless, the majority of IBS patients are normal or overweight. Female sex and anxiety predict a high degree of food-related symptoms in IBS.     

Lactose intolerance in patients with irritable bowel syndrome from northern India: a case-control study

BACKGROUND AND AIM: Symptoms of irritable bowel syndrome (IBS) and lactose intolerance (LI) overlap. Data on the frequency of LI in patients with IBS from India are scanty. The aim of this study was to evaluate: (i) the frequency of LI in patients with IBS and its various subtypes as compared with healthy subjects (HS) from northern India; (ii) the relationship between self-reported milk intolerance and laboratory evidence of LI; and (iii) the role of small intestinal bacterial overgrowth in LI in patients with IBS. METHODS: 124 patients with IBS (Rome II criteria) and 53 age- and gender-matched HS were studied for LI using the lactose hydrogen breath test (LHBT) and the lactose tolerance test (LTT). Symptoms following lactose ingestion (diarrhea, bloating or distension) during the test and history of milk intolerance were recorded. Sixty-nine of the patients with IBS also underwent a glucose hydrogen breath test (GHBT). Patients with IBS were classified into those with diarrhea (IBS-D; >3 loose stools/d), constipation predominant (IBS-C; <3 stools/week) and indeterminate (IBS-I; between >or=3/week and 相似文献   

Are adverse food reactions linked to irritable bowel syndrome?

Objective: We undertook to determine whether adverse food reactions play a role in irritable bowel syndrome (IBS).
Methods: A systematic review of the literature using Medline (1980–1996), targeting IBS and adverse food reactions, was performed. All clinical trials whereby dietary exclusion was followed by food challenge were selected. Each study was reviewed using a structured format to examine methodological issues and study outcomes.
Results: Of the seven studies included, the positive response to an elimination diet ranged from 15% to 71%; double-blind placebo-controlled challenges identified problem foods in 6% to 58% of cases. Milk, wheat, and eggs were most frequently identified to cause symptom exacerbation; of the foods identified the most common trait was a high salicylate content. Foods high in amines were also identified. Studies of diarrhea-predominant IBS identified a higher percentage of adverse food reactions. However, all studies had major limitations in their trial designs, including inadequate patient selection, appropriateness of—and duration of—exclusion diets, and methods of food challenge.
Conclusion: Whether adverse reactions to foods are a key factor in exacerbating IBS symptoms or whether dietary manipulation is a valid treatment option is unclear. Carefully designed controlled clinical trials are now needed to specifically test the potential role of adverse food reactions in diarrhea-predominant IBS.     

The role of food allergy in atopic dermatitis

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory skin disease affecting more than 10% of all children. Sensitization to foods triggers isolated skin symptoms in about 30% of children. These symptoms include immediate reactions within minutes after ingesting food without exacerbation of AD and early and late exacerbations of AD. It is important to identify clinically relevant sensitizations to foods using skin prick tests, a specific IgE blood test (ImmunoCAP; Phadia, Portage, MI, USA), and double-blind, placebo-controlled food challenges to initiate appropriate dietary interventions and avoid unnecessary dietary restrictions. Children with AD triggered by food allergens demonstrate a distinct immune response upon stimulation of their peripheral blood mononuclear cells with food allergen. A defective skin barrier and increased intestinal permeability appear to facilitate allergen sensitization. Appropriate skin care to maintain skin barrier function and dietary avoidance of highly allergenic foods during infancy may help to prevent allergen sensitization, thereby reducing the severity of AD and food allergies.     

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.     

HRQoL questionnaire evaluation in lactose intolerant patients with adverse reactions to foods

The occurrence of patients with gastrointestinal symptoms attributed either to food allergy or intolerance has significantly increased. Nevertheless, an accurate and detailed case history, a systematic evaluation and the outcomes of specific allergy tests to identify the offending foods, including “in vivo” and “in vitro” allergy tests, are often negative for food allergy and may indicate a lactose intolerance, which is a recurrent condition affecting about 50% of adults. The aims of our study were the following: (1) What is the real incidence of the food hypersensitivity and the primary lactose intolerance in patients with gastrointestinal symptoms, initially referred to allergy or food intolerance? (2) Does lactose intolerance affect the quality of life and compliance to the therapy program? We investigated 262 consecutive patients, 72 men and 190 women. An accurate and detailed history and clinical examination were completed to investigate the offending foods. The evaluation in each patient included: allergy tests, lactose H₂ breath test (LHBT) and the HRQoL questionnaire. Five years after the diagnosis of lactose intolerance, a questionnaire on the persistence of gastrointestinal symptoms after lactose ingestion and the diet compliance was distributed. Our results demonstrate an high prevalence of lactose intolerance, more frequent in women; in these patients, bloating and diarrhea are the most reported symptoms. We observe only a significant positive correlation between adverse drug reaction (ADR) and LHBT+ patients, but not an augmented prevalence of food allergy and a negative impact on the HRQoL questionnaire of lactose intolerance.     

Les allergies alimentaires

The incidence of food allergy appears to be on the increase in industrialized societies. The reasons suggested are consumption of new products and the evolution of food technology. The public perceives food allergies differently from doctors: adverse reactions to foods are misclassified as food allergies although they are in most of the cases non-allergic food intolerance or food aversion. Indeed, in controlled studies, a low prevalence of food allergy although they are in most of the cases non-allergy has been found (1–2% in adults, 2–8% in children). Despite a number of advances in the field of diagnosis and therapy, the standard methods of diagnosis and therapy for food allergies remain the same: double-blind placebo-controlled food challenge and avoidance. Reports on the effects of food processing indicate that certain processes for certain foods can either eliminate, reduce, or not change the allergenic potential. As more food allergen identification and information on the protein structures responsible becomes available, perhaps better ways to use processing methods to reduce or remove allergenicity may become apparent and feasible.     

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.     

Fructose intolerance in IBS and utility of fructose-restricted diet

INTRODUCTION: Whether dietary fructose intolerance causes symptoms of irritable bowel syndrome (IBS) is unclear. We examined the prevalence of fructose intolerance in IBS and long-term outcome of fructose-restricted diet. METHODS: Two hundred and nine patients with suspected IBS were retrospectively evaluated for organic illnesses. Patients with IBS (Rome II) and positive fructose breath test received instructions regarding fructose-restricted diet. One year later, their symptoms, compliance with, and effects of dietary modification on lifestyle were assessed using a structured interview. RESULTS: Eighty patients (m/f=26/54) fulfilled Rome II criteria. Of 80 patients, 31 (38%) had positive breath test. Of 31 patients, 26 (84%) participated in follow-up (mean=13 mo) evaluation. Of 26 patients, 14 (53%) were compliant with diet; mean compliance=71%. In this group, pain, belching, bloating, fullness, indigestion, and diarrhea improved (P<0.02). Of 26 patients, 12 (46%) were noncompliant, and their symptoms were unchanged, except belching. The mean impact on lifestyle, compliant versus noncompliant groups was 2.93 versus 2.57 (P>0.05). CONCLUSIONS: About one-third of patients with suspected IBS had fructose intolerance. When compliant, symptoms improved on fructose-restricted diet despite moderate impact on lifestyle; noncompliance was associated with persistent symptoms. Fructose intolerance is another jigsaw piece of the IBS puzzle that may respond to dietary modification.     

Intestinal inflammatory profile shows increase in a diversity of biomarkers in irritable bowel syndrome

Abstract

Background: It has been proposed that irritable bowel syndrome (IBS) is a low-grade mucosal inflammatory disease.

Objective: To characterize the intestinal inflammatory profile in IBS patients with or without fructose intolerance.

Design: Patients referred to colonoscopy with IBS complaints were screened for participation. IBS patients diagnosed according to the Rome II criteria and with no organic gastrointestinal disease were included in the study. One subgroup was patients included in a fructose-reduced diet study for 2 months with effects based on VAS symptom scores. Healthy controls were subjects under investigation of colorectal cancer screening with no IBS or other gastrointestinal diseases. All patients included had normal histology from rectum. Mucosal cytokines, chemokines and growth factors were measured by multiplex technology.

Results: Of 27 inflammatory markers tested in the mucosal tissue, 13 were significantly increased and none was significantly decreased in IBS as compared to controls. Significantly increased were the proinflammatory cytokines tumor necrosis factor, the typical TH1 markers IFNγ, IL-1β, IL-2 and RANTES, the typical TH2 markers IL-5 and IL-9, the TH17 marker IL-17, TNF, the pleiotropic IL-15, and the growth factors bFGF and GM-CSF. In IBS patients with fructose intolerance only IL-5 was significantly increased compared to patients without fructose intolerance.

Conclusions: A dysregulated mucosal inflammatory profile with an increased level of TH1, TH2 and TH17 markers, and growth factors were observed in bowel mucosa in of IBS patients when compared to healthy controls.     

Allergen Component Testing for Food Allergy: Ready for Prime Time?

Food allergies can cause life-threatening reactions and greatly influence quality of life. Accurate diagnosis of food allergies is important to avoid serious allergic reactions and prevent unnecessary dietary restrictions, but can be difficult. Skin prick testing (SPT) and serum food-specific IgE (sIgE) levels are extremely sensitive testing options, but positive test results to tolerated foods are not uncommon. Allergen component-resolved diagnostics (CRD) have the potential to provide a more accurate assessment in diagnosing food allergies. Recently, a number of studies have demonstrated that CRD may improve the specificity of allergy testing to a variety of foods including peanut, milk, and egg. While it may be a helpful adjunct to current diagnostic testing, CRD is not ready to replace existing methods of allergy testing, as it not as sensitive, is not widely available, and evaluations of component testing for a number of major food allergens are lacking.     

Risk factors for irritable bowel syndrome: role of analgesics and food sensitivities

OBJECTIVE: Symptoms of irritable bowel syndrome (IBS) are reported by 10% of the general population; however, evaluation of traditional risk factors has not provided any insight into the pathogenesis of this condition. The objective of this study was to identify additional risk factors for irritable bowel syndrome. METHODS: A valid self-report questionnaire that records the gastrointestinal (GI) symptoms required for a diagnosis of IBS, self-reported measures of potential risk factors, and a psychosomatic symptom checklist was mailed to an age-and gender-stratified random sample of Olmsted County, Minnesota residents aged 30-64 yr. A logistic regression model that adjusted for age, gender, and psychosomatic symptom score was used to identify factors significantly associated with IBS. RESULTS: A total of 643 (72%) of 892 eligible subjects returned the survey. IBS symptoms were reported by 12% of the respondents. IBS was significantly associated with use of analgesics (acetaminophen, aspirin, or nonaspirin nonsteroidal antiinflammatory drugs) for reasons other than IBS, reporting a food allergy or sensitivity, and ratings of somatic symptoms. No association was detected for age, gender, body mass index, smoking history, alcohol use, educational level, exposure to pets in the household, or water supply. Among subjects reporting the use of just one type of analgesic, IBS was associated with acetaminophen but not aspirin or nonaspirin nonsteroidal antiinflammatory drugs used alone. The odds of having IBS were higher among subjects reporting more reasons for taking analgesics and intolerance to a higher number of foods. CONCLUSIONS: IBS is significantly associated with analgesic use. However, this is confounded by other somatic pain complaints. IBS symptoms are associated with the reporting of many food allergies or sensitivities. The role of food-induced symptoms in IBS requires further investigation.     

Intestinal Permeability in Long-Term Follow-up of Patients with Celiac Disease on a Gluten-Free Diet

Intestinal permeability is frequently abnormal in patients with celiac disease. The long-term effect of a gluten-free diet on intestinal permeability and the correlation of intestinal permeability with a gluten-free diet are not known. The objectives of this study were to determine the responses of intestinal permeability and antibody testing to gluten free diet and the degree of correlation of these measurements with gluten ingestion. In this prospective study, patients with celiac disease were divided into three groups based on length of time on a gluten-free diet: Group A, < 1 month; Group B, 1 month–1 year; Group C, > 1 year. Patients in Groups B and C were tested at baseline and at 4–12 weeks later for the following: lactulose/mannitol intestinal permeability, endomysial antibody, and 3-day food record. Permeability tests were also performed in Group A and control subjects. Intestinal permeability was elevated in newly diagnosed celiac disease and in individuals on a gluten-free diet for less than 1 year. Intestinal permeability was normal in 80% at visit 1 and 87% at visit 2 in individuals with celiac disease on a gluten-free diet for more than a year. Trace gluten ingestion was associated with increased intestinal permeability on visit 2 (P = 0.0480). The sensitivity of detecting gluten ingestion as measured by a 3-day food record was higher for permeability testing (29 and 36%) compared with endomysial antibody testing (18 and 18%) for visits 1 and 2, respectively. Intestinal permeability normalizes in the majority of individuals with celiac disease on a gluten-free diet. Gluten ingestion as measured by a 3-day food record correlates with intestinal permeability measurements. The role of permeability testing in the follow-up of patients with celiac disease warrants further investigation.     

Diagnosis of Food Allergy: Epicutaneous Skin Tests, In Vitro Tests, and Oral Food Challenge

Food allergy is becoming an increasingly common diagnosis. Because of this increase in prevalence, it is imperative that physicians evaluating patients with possible adverse reactions to foods understand the currently available assays and how they should best be used to accurately diagnose the disease. Simple tests such as skin prick testing (SPT) and serum food-specific IgE testing are the most commonly used diagnostic tests to evaluate for IgE-mediated food reactions. However, these tests, which measure sensitization and not clinical allergy, are not without pitfalls, and their utility must be appreciated to avoid over- and underdiagnosis. Although the physician-supervised oral food challenge remains the gold standard for food allergy diagnosis, a careful medical history paired with SPT and serum food-specific IgE testing often can provide a reliable diagnosis. In this review, we examine the usefulness and pitfalls of SPT and serum food-specific IgE levels, as well as examine atopy patch testing and other emerging tests, such as component-resolved diagnostics and the basophil activation test. Finally, we describe the use of the double-blind, placebo-controlled oral food challenge as the current gold standard for food allergy diagnosis.     

饮食在肠易激综合征症状发作和治疗中的作用

流行病学研究资料提示,肠易激综合征(irritable bowel syndrome,IBS)患者的症状发作与饮食有关.饮食影响IBS症状的机制仍未完全阐明,可能与食物的促动力和促胃肠激素分泌作用、食物不耐受、食物过敏和不良进食习惯等有关.有证据表明采用食物剔除和添加膳食纤维、益生菌和益生元等特殊食物成分的饮食调整治疗能缓解IBS的症状.本文从IBS与食物有关的表现、饮食影响IBS症状的原因和机制、饮食对IBS治疗的作用3个方面总结了相关研究的进展.     

Symptoms discriminate irritable bowel syndrome from organic gastrointestinal diseases and food allergy

BACKGROUND: The value of specific gastrointestinal symptoms in discriminating irritable bowel syndrome (IBS) from organic disease has been documented. In contrast, there have been few attempts to identify symptoms that discriminate irritable bowel syndrome from food allergy, despite similarities in their respective symptom complexes. We aimed to investigate the value of symptoms in discriminating irritable bowel syndrome from organic disease and food allergy. METHODS: Subjects (n = 288) were recruited from consecutive patients presenting to the Internal Medicine, Gastroenterology and Allergy Units in Chieti. Patients completed the validated Bowel Disease Questionnaire (BDQ) prior to an independent diagnostic evaluation, which included endoscopy when appropriate. Food allergy was diagnosed using a 2-week elimination diet, followed by a placebo-controlled food challenge test, a skin prick test and serum RAST for specific IgE for suspected foods or additives. The results of the BDQ were not considered in formulating a diagnosis. In total, 99 patients were diagnosed with the IBS, 79 patients were diagnosed with organic disease and 22 patients were diagnosed with food allergy. A further 88 patients with extraintestinal allergies were included as a control group. RESULTS: Based on logistic regression analysis, six symptom items discriminated IBS from organic disease, while five symptoms discriminated patients with IBS from control subjects. A diagnosis of IBS compared to organic disease was positively associated with straining on defaecation (P=0.0001), diarrhoea (P=0.001) and abdominal bloating (P=0.01), but was negatively associated with pain in the upper abdomen (P=0.0004), reflux (P=0.0001) and appetite loss (P=0.004). A diagnosis of IBS compared to extraintestinal allergy was positively associated with pain relieved by bowel movement (P=0.0001), pain in the lower abdomen (P=0.0006), pain in both the upper and lower abdomen (P=0.003), frequent pain (P=0.001) and abdominal bloating (P=0.0009). In comparison between IBS and food allergy patients, a diagnosis of IBS was positively associated with pain in the lower abdomen (P=0.001), pain relieved by bowel movements (P=0.001), frequent pain (P=0.02) and abdominal bloating (P=0.03). CONCLUSION: Symptoms appear to be useful for discriminating IBS from organic gastrointestinal disease and food allergy.