Diet is important in triggering the symptoms of irritable bowel syndrome (IBS). This study investigated the impact of dietary guidance on the symptoms, quality of life and habitual diet of patients with IBS. Forty-six patients who fulfilled the Rome III criteria for the diagnosis of IBS were included. Of these patients, 17 completed the entire study. Each patient attended three sessions (~45 min in duration) and received individual guidance on their dietary management. The patients were asked to complete the following questionnaires prior to receiving the dietary guidance, and at least 3 months subsequently: The Birmingham IBS symptom score questionnaire, the IBS Quality of Life (IBS-QOL) questionnaire, the Short-Form Nepean and Dyspepsia Index (SF-NDI) and the MoBa Food Frequency Questionnaire (MoBa FFQ). The time at which patients completed the questionnaires following dietary guidance ranged from 3–9 months (median, 4 months). The total IBS symptom scores were reduced once the patients had received dietary guidance (P=0.001). The total score for the quality of life, as assessed by the IBS-QOL and the SF-NDI, increased significantly following the dietary guidance sessions (P=0.003 and P=0.002, respectively). There were no statistical differences in the intake of calories, carbohydrate, fiber, protein, fat or alcohol in the patients with IBS following dietary guidance. There were increases in the consumption of dairy products, β-carotene, retinol equivalents, riboflavin, vitamin B12 and calcium, although only the increase in vitamin B12 consumption was statistically significant. There was a significant reduction in the consumption of certain fruits and vegetables that were rich in highly fermentable short-chain carbohydrates, disaccharides, monosaccharides and polyols, as well as insoluble fibers. In conclusion, three 45-min dietary guidance sessions, administered by a nurse, reduced the symptoms and improved the quality of life of patients with IBS, and resulted in an adequate intake of vitamins and minerals. Individual dietary guidance is a cost-effective option for the management of IBS.
Irritable bowel syndrome (IBS) is a chronic functional bowel disorder characterized by a combination of symptoms that have a considerable impact on the patient’s quality of life. These symptoms include abdominal pain or discomfort and altered bowel habits (
Approximately two-thirds of patients with IBS consider their symptoms to be related to their diet (
In a previous study by our group, dietary guidance administered individually to patients with IBS reduced the symptoms of the condition and improved their quality of life, in addition to affecting their habitual diet so that their intake of minerals and vitamins became normalized (
Patients who had been referred to the gastroenterology department of Stord Helse-Fonna Hospital (Stord, Norway), and who fulfilled the Rome III criteria for the diagnosis of IBS were considered for inclusion in the study. Although both genders were able to participate, the patients were required to be between 18 and 69 years of age. Exclusion criteria comprised the presence of organic gastrointestinal disease, clinically significant systemic diseases, pregnancy or lactation, drug abuse, serious psychiatric diseases and collaboration issues. In addition, with the exception of appendectomy, cesarean section and hysterectomy, patients who had undergone abdominal surgery were excluded. This study was performed in accordance with the Declaration of Helsinki and was approved by the Regional Committee for Medical and Health Research Ethics West, Bergen, Norway. All patients provided oral and written consent to participate.
In total, 46 patients were included in the study. This included 35 females and 11 males with a mean age of 35 years (range, 18–69 years). Of these, 21 reported diarrhea (IBS-D), 18 reported constipation (IBS-C) and seven reported a mixture of both symptoms (IBS-M) as the predominant symptom of IBS. The patients underwent a complete physical examination, a gastroscopy with duodenal biopsies, a colonoscopy with segmental biopsies and several blood tests to exclude other organic causes for their symptoms. Each patient received three sessions of individual guidance on dietary management from a registered nurse with a specific education in IBS diet, with each session lasting ~45 min. The patients were asked to complete the following questionnaires before and ≥3 months subsequent to receiving the dietary guidance: The Birmingham IBS symptom score questionnaire, the IBS-Quality of Life (IBS-QOL) questionnaire, the Norwegian version of the Short-Form Nepean and Dyspepsia Index (SF-NDI) questionnaire and the MoBa Food Frequency Questionnaire (MoBa FFQ).
Each patient attended three 45 min sessions with a registered nurse with special training in the IBS diet, and seven years experience of providing dietary guidance to patients with IBS. The sessions were scheduled with intervals of ≥2 weeks between them. The information at the sessions was provided orally, and using charts and illustrative drawings. Written information was also supplied.
In the first session, the patient received general information with regard to the importance of regular meals and healthy eating habits, along with the effect of the diet on the development of symptoms. Emphasis was placed on the role of poorly absorbed, highly fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs), although patients were also informed of the effects of soluble and insoluble dietary fibers. It was emphasized that milk and dairy products were not triggers for IBS symptoms, and that the patients should consume dairy products daily. The patient was asked to keep a diary in which they recorded the time of eating/drinking, and the types of food and drinks they ingested daily. In addition, they were asked to report the occurrence of abdominal pain, abdominal distention and bloating, as well as stool frequency and consistency. The patients were instructed to try protein-, fat-, and carbohydrate-rich/poor diets and report the symptoms for each in the diary. This was performed over a 2-week period.
In the second scheduled session, the information provided in the first session was summarized, before the diary was examined to determine which food items may be triggering the patient’s symptoms. The patients were then advised to avoid these items and other items that were rich in FODMAPs and insoluble fibers, such as onions, garlic, paprika, cabbage, carbonated beverages, ‘lite’ products (those containing artificial sweeteners), bananas, beans and peas. The patient was asked to replace wheat and wheat products with spelt and spelt products, respectively, and was provided with a list of vegetables and fruits that contained lower levels of FODMAPs and insoluble fibers (
During the third and final session, the patient’s experience regarding the management of their diet was discussed with the nurse, so that the patient and nurse were then able to utilize this information to design a suitable diet for the patient to follow.
The Birmingham IBS symptom score questionnaire was developed to measure the symptoms of patients with IBS. It is disease-specific, acceptable to patients and suitable for self-completion. Its dimensions have been demonstrated to have good reliability, external validity and sensitivity (
The quality of life in patients with IBS was assessed by the IBS-QOL and SF-NDI questionnaires.
The IBS-QOL questionnaire is a 34-item, IBS-specific quality of life measure that assesses physical and psychosocial functioning as a result of IBS (
The SF-NDI questionnaire is a disease-specific measure of the health-related quality of life (HRQoL), with 10 questions divided into five subscale scores (tension, interference with daily activities, disruption to regular eating/drinking, knowledge towards/control over disease symptoms and interference with work/study). Each question has five options, ranging from 1 (not at all) to 5 (extremely); thus, the total score ranges from 10–50, as per the developer’s original calculation formula, with higher scores indicating worse functioning or symptoms. This questionnaire was constructed and validated primarily in patients with dyspepsia (
Dietary intake was assessed using a semi-quantitative, self-administered food frequency questionnaire (MoBa FFQ). The MoBa FFQ asks participants to report the frequency of consumption and portion size of certain items over a defined period of time. Each item is defined by a series of foods or beverages. Additional questions on food purchasing and preparation methods enable the analysis software to further refine nutrient calculations. The MoBa FFQ used in this study was developed and validated by the Norwegian Institute of Public Health in Oslo, Norway (
The paired t-test was used to analyze the data. The data are presented as the mean ± SEM values, and P<0.05 was considered to indicate a statistically significant difference.
Of the 46 patients recruited to this study, 18 abandoned the study; one was excluded due to non-compliance and one due to cooperation problems; four became better following the dietary guidance sessions, and then lost interest in and motivation for completing the study; two were diagnosed with celiac disease; one was diagnosed with lupus; one became pregnant and one moved abroad during the study. Thus, 17 of the original 46 patient cohort completed the study. These patients comprised 12 females and five males with a mean age of 34 years (range, 20–45 years); six of the 17 were IBS-D, eight were IBS-C and three were IBS-M. The time taken between receiving dietary guidance and completing the second set of questionnaires ranged from 3–9 months (median, 4 months).
The total scores of the Birmingham IBS symptom score questionnaires before and subsequent to receiving dietary guidance were 41.47±1.62 and 35.71±1.12, respectively. The reduction in symptoms was statistically significant (P=0.001). All three of the questionnaire dimensions (i.e., abdominal pain, diarrhea and constipation) were also reduced following the dietary guidance sessions; however, the result for constipation was not statistically significant (
The total IBS-QOL score increased significantly from 125.4±4.2 to 136.8±3.8 following the dietary guidance sessions (P=0.003). This improvement was statistically significant in all domains, with the exception of the impact on relations (
The total SF-NDI scores (which reflect the reduction in HRQoL) before and following the dietary guidance sessions were 29.1±2.2 and 20.2±1.5, respectively. This improvement in HRQoL was statistically significant (P=0.002;
There were no statistically significant differences in the intake of calories, carbohydrate (total and starch), fiber, protein, fat (total, saturated and trans-, mono- and polyunsaturated), sugar or alcohol in the patients with IBS who received dietary guidance (
There was a high incompletion rate in this study, with a completion rate of only 37%, and a rate of abandonment of 39%. This was within the limits (30–40%) of comparative studies (
A previous study demonstrated that although patients with IBS purposely avoided certain food items that were rich in FODMAPs, they unknowingly maintained a high FODMAP intake due to the consumption of alternative FODMAP-rich sources (
The question of how dietary guidance should be provided, and what should it contain, remains unanswered. Individual guidance has been demonstrated to be effective in reducing the symptoms and improving the quality of life of patients with IBS (
In the present study, the replacement of wheat and wheat products with spelt and spelt products, respectively, enabled the patients with IBS to continue to consume food items, such as bread, without a drastic change to their lifestyle. Spelt is known to contain fewer galactans and fructans (both of which are FODMAPs) than wheat. This observation challenges the emerging concept that gluten has a role in the development of symptoms in IBS (
The present results demonstrate that three sessions of dietary guidance, each lasting 45 min and provided by a nurse, may reduce the symptoms and improve the quality of life of patients with IBS, as well improving their vitamin and mineral intake. This effect has been demonstrated to be long-term (
(A) Total score and scores on the three dimensions [(B) abdominal pain, (C) diarrhea and (D) constipation] of the Birmingham irritable bowel syndrome (IBS) symptom score questionnaire in patients with IBS before and following dietary guidance sessions. *P<0.05 and **P<0.01.
Total score for quality of life in patients with irritable bowel syndrome (IBS) before and following dietary guidance sessions, as assessed by the Irritable Bowel Syndrome-Quality of Life (IBS-QOL) questionnaire. **P<0.01.
Total score for the reduction in quality of life, as detected by the Short-Form Nepean and Dyspepsia Index (SF-NDI) quality of life questionnaire. **P<0.01.
Scores on the eight domains of the Irritable Bowel Syndrome-Quality of Life (IBS-QOL) questionnaire in patients with IBS before and following dietary guidance sessions.
IBS-QOL score | |||
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Domain | Before dietary guidance | Following dietary guidance | P-value |
Dysphoria | 28.1±1.4 | 31.5±0.9 | 0.009 |
Interference with activity | 18.6±0.7 | 20.9±0.7 | 0.003 |
Body image | 18.1±0.8 | 20.0±1.1 | 0.007 |
Health worry | 15.2±0.7 | 16.9±0.6 | 0.001 |
Food avoidance | 5.8±0.6 | 4.6±0.4 | 0.018 |
Social reactions | 18.8±0.8 | 20.6±0.7 | 0.021 |
Sexual function | 8.2±0.4 | 8.9±0.3 | 0.035 |
Impact on relations | 12.8±0.4 | 13.4±0.4 | 0.172 |
Data are presented as the mean ± SEM.
P<0.05 and
P<0.01.
Daily intake of macronutrients and alcohol in patients with irritable bowel syndrome (IBS) before and following dietary guidance sessions.
Before dietary guidance | Following dietary guidance | P-value | |
---|---|---|---|
Energy (kcal) | 1968±183 | 1889±219 | 0.610 |
Carbohydrates (g) | |||
Total | 249.7±28.6 | 228.3±30.0 | 0.342 |
Starch | 125.8±15.5 | 108.2±13.1 | 0.185 |
Fiber (g) | 27.4±2.5 | 23.1±2.2 | 0.093 |
Protein (g) | 75.7±5.5 | 78.2±9.4 | 0.704 |
Fats (g) | |||
Total | 72.5±6.3 | 72.3±7.6 | 0.967 |
Saturated | 26.6±2.6 | 26.5±3.2 | 0.965 |
Cholesterol | 232.6±26.0 | 288.6±38.9 | 0.040 |
Trans | 1.4±0.2 | 1.8±0.4 | 0.243 |
Monounsaturated | 24.2±2.1 | 24.4±2.4 | 0.918 |
Polyunsaturated | 14.9±1.4 | 13.9±1.3 | 0.334 |
Sugar (g) | 50.4±8.3 | 49.4±9.2 | 0.876 |
Alcohol (ml) | 1.4±0.6 | 1.2±0.4 | 0.620 |
Data are presented as the mean ± SEM.
P<0.05.
Weekly pattern of meal types in patients with irritable bowel syndrome (IBS) before and following dietary guidance sessions.
Number of meals | |||
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Meal type | Before dietary guidance | Following dietary guidance | P-value |
Breakfast | 2.1±0.5 | 1.8±0.4 | 0.260 |
Morning snack | 5.4±0.6 | 4.4±0.5 | 0.256 |
Lunch | 3.9±0.6 | 3.0±0.5 | 0.219 |
Snack before dinner | 6.2±0.6 | 5.9±0.6 | 0.716 |
Dinner | 1.4±0.2 | 1.3±0.2 | 0.579 |
Evening snack | 5.6±0.6 | 6.2±0.5 | 0.370 |
Supper | 3.1±0.5 | 3.2±0.4 | 0.675 |
Night time meal | 7.4±0.5 | 7.2±0.5 | 0.867 |
Data are presented as the mean ± SEM.
Daily intake of dairy products, artificial sweeteners and soft drinks in patients with irritable bowel syndrome (IBS) before and following dietary guidance sessions.
Dairy products | Before dietary guidance | Following dietary guidance | P-value |
---|---|---|---|
Milk products, whole fat (g) | 0.8±0.5 | 6.2±5.0 | 0.262 |
Milk products, low fat (g) | 118.8±59.9 | 138.7±82.8 | 0.506 |
Sour milk with probiotic supplement (g) | 31.5±29.3 | 4.5±2.6 | 0.339 |
Yoghurt (g) | 14.1±4.6 | 34.4±10.6 | 0.070 |
Soya milk (g) | 0.9±0.6 | 1.3±0.9 | 0.332 |
Cheese, whole fat (g) | 7.0±2.9 | 7.8±3.7 | 0.676 |
Cheese, low fat (g) | 0.2±0.1 | 0.4±0.2 | 0.260 |
Brown goat’s cheese (g) | 1.1±0.4 | 2.6±1.8 | 0.335 |
Artificial sweeteners (mg) | 0.02±0.01 | 0.01±0.01 | 0.163 |
Soft drinks, sweetened (ml) | 71.3±31.9 | 53.5±20.7 | 0.478 |
Soft drinks, unsweetened (ml) | 91.7±39.8 | 37.5±29.2 | 0.085 |
Data are presented as the mean ± SEM.
Daily intake of vitamins and minerals in patients with irritable bowel syndrome (IBS) before and following dietary guidance sessions.
Before dietary guidance | Following dietary guidance | P-value | |
---|---|---|---|
Vitamins | |||
β-carotene (mg) | 2543±511 | 2721±360 | 0.624 |
Folate (μg) | 224.8±17.8 | 223.2±28.8 | 0.942 |
Niacin equivalents (μg) | 28.3±2.0 | 29.5±3.1 | 0.584 |
Retinol equivalents (mg) | 839±95 | 1039±152 | 0.199 |
Riboflavin (mg) | 1.5±0.2 | 1.7±0.3 | 0.513 |
Thiamin (mg) | 1.3±0.1 | 1.2±0.2 | 0.727 |
Vitamin B6 (mg) | 1.4±0.1 | 1.3±0.1 | 0.478 |
Vitamin B12 (μg) | 4.5±0.5 | 6.1±1.1 | 0.042 |
Vitamin C (mg) | 124.6±18.3 | 126.1±16.6 | 0.913 |
Vitamin D (μg) | 2.9±0.4 | 3.8±0.5 | 0.079 |
Vitamin E (mg) | 10.2±0.9 | 10.1±0.9 | 0.941 |
Minerals | |||
Calcium (mg) | 773±85 | 884±186 | 0.373 |
Copper (mg) | 1.2±0.1 | 1.1±0.1 | 0.383 |
Iron (mg) | 9.7±0.7 | 8.9±0.9 | 0.412 |
Magnesium (mg) | 358±28.3 | 333.5±42.8 | 0.500 |
Phosphorus (mg) | 1455±110 | 1475±213 | 0.901 |
Potassium (mg) | 3577±281 | 3454±400 | 0.686 |
Selenium (μg) | 50.1±3.7 | 54.6±5.9 | 0.316 |
Sodium (mg) | 2694±209 | 2618±276 | 0.754 |
Zinc (mg) | 9.6±0.7 | 9.5±1.2 | 0.925 |
Data are presented as the mean ± SEM.
P<0.05.
Daily intake of various vegetables, fruits and berries in patients with irritable bowel syndrome (IBS) before and following dietary guidance sessions.
Daily intake (g) | |||
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Vegetables/fruits/berries | Before dietary guidance | Following dietary guidance | P-value |
Cauliflower: raw | 1.4±0.9 | 0.7±0.6 | 0.300 |
Cauliflower: cooked | 4.9±2.0 | 4.9±2.8 | 0.996 |
Broccoli: raw | 1.5±1.0 | 1.2±1.0 | 0.821 |
Broccoli: cooked | 5.2±1.4 | 5.4±2.2 | 0.909 |
Peas | 2.1±0.5 | 0.4±0.2 | 0.006 |
Cabbage: raw | 1.5±1.0 | 0.1±0.1 | 0.193 |
Cabbage: cooked | 2.3±0.7 | 0.2±0.2 | 0.010 |
Paprika: raw | 4.9±1.4 | 1.8±1.3 | 0.006 |
Paprika: cooked | 3.3±0.9 | 0.7±0.3 | 0.019 |
Onion, leak or garlic | 11.5±2.9 | 1.7±0.8 | 0.003 |
Tomatoes | 5.7±1.6 | 11.2±3.4 | 0.102 |
Potatoes: fried | 5.5±1.2 | 7.6±1.3 | 0.070 |
Potatoes: cooked, mashed or gratin | 63.7±9.8 | 61.1±8.5 | 0.770 |
Oranges | 44.5±17.4 | 47.5±17.2 | 0.884 |
Bananas | 24.1±8.0 | 4.7±1.6 | 0.023 |
Grapes | 16.2±5.0 | 2.6±1.4 | 0.016 |
Pears | 16.5±6.3 | 4.5±2.4 | 0.059 |
Apples | 29.3±8.0 | 34.7±13.6 | 0.688 |
Peaches | 8.9±3.2 | 6.7±3.1 | 0.553 |
Grapefruit | 1.4±0.9 | 0.6±0.3 | 0.421 |
Mangos | 4.3±2.1 | 4.9±3.3 | 0.885 |
Plums | 2.3±0.9 | 4.4±2.9 | 0.497 |
Melons | 4.9±1.4 | 4.5±1.7 | 0.692 |
Blueberries | 6.9±2.1 | 6.5±2.1 | 0.879 |
Strawberries | 12.2±3.0 | 12.2±5.1 | 0.992 |
Prunes: dried | 0.3±0.1 | 0.7±0.3 | 0.188 |
Apricots: dried | 0.5±0.3 | 0.9±0.4 | 0.329 |
Mushrooms | 1.7±0.3 | 1.4±0.4 | 0.513 |
Green beans | 0.3±0.2 | 0.3±0.2 | 1.000 |
Data are presented as the mean ± SEM.
P<0.05 and
P<0.01.
Daily intake of patients with irritable bowel syndrome (IBS), demonstrating the replacement of wheat products with spelt products following dietaryguidance sessions.
Daily intake (g) | |||
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Wheat/spelt products | Before dietary guidance | Following dietary guidance | P-value |
White bread | 3.4±1.7 | 4.4±1.7 | 0.636 |
Dark bread | 85.4±27.3 | 48.0±21.5 | 0.319 |
Spaghetti and other pasta | 15.1±2.0 | 13.4±1.6 | 0.456 |
Waffles or pancakes | 10.1±2.0 | 7.1±1.3 | 0.103 |
Chocolate cakes | 5.1±0.8 | 2.8±0.7 | 0.002 |
Crisp bread | 15.4±7.2 | 17.2±6.3 | 0.723 |
Sweet buns | 4.7±1.5 | 1.1±0.3 | 0.025 |
Data are presented as the mean ± SEM.
P<0.05 and
P<0.01.