Functional Bowel Disorders in Adults
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Background: Chronic abdominal pain, bloating, constipation, diarrhea, and stool irregularity are common symptoms in primary care and gastroenterology. A routine diagnostic evaluation fails to reveal any underlying somatic condition in about half of the affected patients, who are therefore said to have a functional bowel disorder. Physicians are often unsure how extensive the work-up must be to exclude a somatic cause.
Methods: This review is based on a selective review of the literature, including published guidelines from Germany and abroad.
Results: Functional bowel disorders are diagnosed on the basis of a typical constellation of symptoms and the absence of pathological findings that would adequately explain them (exclusive criteria). The basic diagnostic assessment, consisting of a physical examination, basic laboratory tests, abdominal ultrasonography, and (in women) a gynecological examination, is supplemented by further testing that depends on the patient’s symptoms. Colonoscopy is obligatory to rule out underlying pathological abnormalities. By communicating the diagnosis of irritable bowel syndrome to the patient, the physician shows that the patient’s symptoms and concerns have been taken seriously. The mainstays of treatment are patient education on the benign course of the disease and the encouragement of a salubrious lifestyle. Further treatment options include dietary measures, time-limited symptomatic treatment with drugs, and psychotherapy.
Conclusion: The diagnosis of a functional bowel disorder is based on a thorough history (positive criteria) and a small battery of diagnostic tests to exclude somatic disease. Both the diagnostic assessment and the treatment should be carried out in accordance with published guidelines.
Abdominal symptoms (pain, bloating, stool irregularity, diarrhea, constipation) are common in the general population. In a German survey, 13% of 2050 respondents said they had experienced bloating in the last 7 days, and 11% said they had experienced abdominal pain in the same interval (1). 30% to 50% of all persons with persistent abdominal symptoms seek medical help (2). Their symptoms might be an expression of a physical illness (e.g., Crohn’s disease), a mental illness (e.g., panic disorder), and/or a functional disorder. About half of all adults who consult a primary care physician or gastroenterologist because of chronic abdominal discomfort for more than three months are ultimately diagnosed as having a functional bowel disorder (2, 3). The diagnosis and treatment of functional bowel disorders is often considered difficult or frustrating, both by the patients themselves and by the physicians who treat them (4). Physicians’ and patients’ fears of overlooking a serious bodily illness often lead to extensive and repeated diagnostic testing for the exclusion of disease. Moreover, instead of giving the patient the diagnosis of a functional bowel disorder, physicians often assign euphemistic quasi-diagnoses (e.g., “elongated colon”) or false ones (e.g., Candida hypersensitivity syndrome). As a result, patients often receive treatments for which there is no indication, such as an antifungal drug merely because Candida albicans has been found in the stool.
Many doctors consider functional bowel disorders a diagnosis of exclusion. As a result, primary care physicians tend to perform a more extensive diagnostic work-up than specialists who deal with functional bowel disorders (5).
Functional bowel disorders are generally considered harmless in the medical sense, as they neither cause organic damage nor shorten life expectancy. They can, however, interfere with everyday activities to a varying extent: Patients may be repeatedly absent from work with a medical excuse, or they may find themselves giving up pleasurable activities such as going out to restaurants or going away on vacation. The cost to society is considerably raised by diagnostic tests and treatments for which there is no indication, and by medical excuses from work (6).
Guidelines for the diagnosis and treatment of functional bowel disorders are highly useful in view of the prevalence and societal importance of these conditions, the affected patients’ suffering and impaired quality of life, and the uncertainty and frustration of patients and physicians alike with regard to proper management.
This article deals only with the diagnosis and treatment of functional bowel disorders in adults. Such disorders constitute an important subset of the larger, more general class of functional abdominal disorders. We will not discuss the remainder here, which includes functional gastroduodenal disorders (7), functional biliary disorders (8), functional anorectal symptoms (9), or functional abdominal symptoms in children (10).
Reading this article should enable the reader to
- become acquainted with an appropriate diagnostic algorithm for the exclusion of somatic disease factors,
- diagnose a functional bowel disorder on the basis of positive criteria from the patient’s history,
- communicate the diagnosis of a functional bowel disorder in an appropriate way to the patient,
- become familiar with the various treatment options (dietary, medical, psychotherapeutic).
This article is based on the Rome III expert consensus on functional bowel-related complaints (11); the German (12), British (13) and American (14) guidelines on irritable bowel syndrome (IBS); and the German S3 guideline on functional bodily symptoms (15).
The authors also carried out a selective literature search in the PubMed database.
The definition and classification of functional bowel disorders
Various schemes of diagnostic criteria are in use for the definition and classification of these disorders.
The Rome III and DGVS criteria
The Rome criteria for the classification of functional gastrointestinal disorders were developed in consensus meetings and are now available in their third and most current version, the so-called Rome III criteria. Functional bowel disorders are defined as follows:
- symptoms relating to the middle and lower portions of the gastrointestinal tract (abdominal pain, bloating, stool irregularity, diarrhea, constipation);
- onset at least six months ago, with symptoms at least three days per month in the last three months.
Transient disturbances that do not meet the above temporal criterion are excluded (11). In the Rome I and Rome II criteria, the exclusion of a biochemical or structural disorder was part of the definition. In contrast, the Rome III criteria take account of the possibility that future research might reveal a biochemical or structural problem underlying what are now called functional bowel disorders (11).
In some patients with functional bowel symptoms, special diagnostic techniques that are not included in a routine medical work-up reveal molecular and cellular abnormalities (e.g., high local concentrations of pro-inflammatory cytokines) whose specificity is currently unknown. There is as yet no biomarker for functional bowel symptoms. The German guideline therefore includes a further diagnostic criterion for irritable bowel syndrome, namely, that the patient has no abnormalities characteristic of other diseases that generally cause symptoms of the same type (12).
The Rome III expert panel divided functional bowel disorders into the following types:
- irritable bowel syndrome,
- functional bloating,
- functional constipation,
- functional diarrhea,
- and functional bowel disorder, not otherwise specified.
Irritable bowel syndrome is the commonest type of functional bowel disorder. The Rome III expert panel defined it as follows:
- abdominal pain or discomfort at least three days per month in the past three months
- onset at least six months ago with at least two of the following:
– improvement of symptoms after defecation
– initial change of stool frequency
– initial change of stool consistency and appearance.
For research purposes, irritable bowel syndrome is subclassified into constipation-dominant, diarrhea-dominant, and mixed types (11).
The German guideline on irritable bowel syndrome takes account of the fact that the classic symptom cluster of abdominal pain and stool changes is not present in all patients with the condition. It therefore contains the statement that no single, specific combination of symptoms is obligatory for the diagnosis of IBS.
IBS is present when three criteria are met:
- The patient has suffered chronically, i.e., for more than three months, from persistent symptoms (e.g., abdominal pain, bloating) that the patient and the physician associate with the bowel and that are usually accompanied by changes relating to defecation.
- These symptoms impair the patient’s quality of life and have led the patient to seek medical help.
- The patient has no abnormalities characteristic of other diseases that generally cause symptoms of the same type (12, e1).
The requirement for the exclusion of structural diseases that could account for the patient’s symptoms does not imply that functional bowel symptoms have no biological basis. Advances in basic research have increasingly called the dichotomy between organic and mental illness in question (16).
Classification in psychosocial medicine
In psychosocial medicine, the symptom complex of functional bowel disorders is classified as a somatoform autonomic dysfunction of the lower gastrointestinal tract (F45.32) or as a somatization disorder (F45.0). This classification takes account of the fact that many patients have symptoms outside the gastrointestinal tract, general symptoms such as fatigue and insomnia, pain elsewhere in the body (e.g., headache and backache), and symptoms in other organ systems (urogenital, cardiovascular). Overlap with other functional disorders, such as fibromyalgia syndrome, is common (e3). Nonetheless, only some patients with functional disorders fulfill the criteria for the broader category of somatoform disorders (somatic fixation) (15).
The diagnosis of irritable bowel syndrome is always to be preferred when the patient’s current symptoms are limited to this organ system. On the other hand, if the patient has multiple, major extraintestinal complaints, and/or the patient’s illness behavior is marked by intense fear of disease, great concern about the symptoms, or the persistent conviction that a serious physical illness is present, then a somatoform disorder should be diagnosed instead. 15% to 48% of all patients with irritable bowel syndrome meet the criteria for a somatoform disorder (12). Depressive disorders have been found in 20% to 70%, and anxiety disorders in 20% to 50% (12).
Variations in the temporal course of functional bowel disorders
Among persons with functional bowel disorders, there is marked variation in the severity of gastrointestinal and other physical and mental symptoms, in subjectively experienced impairment, in personal views about the origins and course of their illness, and in the utilization of medical services (Table 1).
- “Non-patients”: persons with functional bowel symptoms who do not consider themselves ill
- “Non-consulters”: persons with functional bowel symptoms who consider themselves ill, but do not seek medical help (although they may treat themselves or obtain paramedical treatment)
- Patients whose disorder takes a mild course
- Patients whose disorder takes a more severe course.
Course and prognosis
Irritable bowel syndrome sometimes resolves spontaneously but usually becomes chronic. A study of the course of IBS revealed that, seven years after receiving a diagnosis of IBS, 55% of patients still met the diagnostic criteria for it, while 21% had improved symptoms and 13% were asymptomatic (e4). IBS is not associated with the development of other organic diseases or with increased mortality. IBS patients do, however, undergo surgery (hysterectomy, cholecystectomy) more commonly than non-IBS patients (11–14).
The biopsychosocial model of functional bowel disorders
Functional bowel disorders can be understood as the product of an interaction of somatic and psychosocial disease factors that contribute to a predisposition to such disorders as well as to their provocation and chronification (16).
The biological factors include a possible genetic predisposition, previous gastrointestinal infections, and food intolerance.
Genetic factors: Twin studies have shown a low genetic contribution and a high environmental contribution to irritable bowel syndrome (13), as well as a common genetic basis for functional disorders (headache, chronic fatigue, chronic pain in multiple regions of the body) (17). About 100 genetic variants in nearly 60 genes have been studied to date. A few positive associations have been described, e.g., with polymorphisms of the serotonin-5 transporter gene (18). The interpretation of genetic studies is complicated by confounding variables such as comorbid mental illness (13).
Gastrointestinal infections: 7% to 36% of patients with irritable bowel syndrome develop their symptoms in the aftermath of a gastrointestinal infection (e5). Postinfectious irritable bowel syndrome has been described after infections with Salmonella, Shigella, Campylobacter, EHEC, Lamblia, and Trichinella. Postinfectious irritable bowel syndrome is due to an interaction of biological and psychosocial factors: The risk of developing irritable bowel syndrome after a gastrointestinal infection can be predicted from the severity of the initial symptoms, the degree of bacterial toxicity, and psychological factors (anxiety, depression, psychosocial stressors) (16, e6) (cf. eTable 1).
Food intolerance: Food intolerance affects 50% to 70% of persons with irritable bowel syndrome and 20% to 25% of the general population. Immune-mediated food intolerance (allergy to particular foods) is rare; non-immune-mediated food intolerance is more common and is often due to malabsorption of lactose, fructose, or sorbitol (19).
Multiple psychological factors contribute to the pathogenesis and course of irritable bowel syndrome.
Parental behavior: Learned patterns of behavior from parents with functional bowel symptoms, as well as family members’ reinforcing effect on illness behavior related to the abdomen, increase the risk of functional abdominal symptoms in adulthood (13). In twins, having one parent with irritable bowel syndrome is an independent risk factor for a functional gastrointestinal illness in the child (e7).
Biographical stressors: Patients with irritable bowel syndrome report having been sexually abused in childhood more commonly than healthy persons or patients with somatic gastrointestinal diseases (odds ratio [OR], 4.1 [95% confidence interval [CI], 1.9–8.6]) (e8). The association of biographical stressors with irritable bowel syndrome is mediated by the manifestation of further bodily symptoms (so-called somatization tendency) (20).
Personality traits: In a prospective, population-based study, marked illness behavior (OR, 5.2 [95% CI, 2.5–11.0]) and increased anxiety (OR, 2.0 [95% CI, 1.0–4.1]) predicted the development of IBS (21).
Social factors: By performing diagnostic tests and treatments that are not indicated, physicians can induce or reinforce patients’ inappropriate fears of disease and illness behavior (15).
Potential pathophysiological mechanisms are listed in Box 1. Some of these are known to be associated with somatic and psychological risk factors, including the following:
- Gastrointestinal infections with disturbances of the intestinal flora and peripheral sensitization
- Emotions (e.g., anxiety) with visceral hypersensitivity and impaired motility
- Biographical stress factors with altered central processing of stimuli
- Psychosocial stressors with disturbances of the hypothalamic-pituitary-adrenocortical axis (16, 20).
IBS is diagnosed on the basis of a stepwise algorithm for somatic and psychological diagnostic evaluation.
Basic diagnostic evaluation
Somatic and psychosocial factors should be assessed simultaneously (Box 2).
The physician taking an initial history should ask open questions so that the patient can describe the symptoms freely. The physician should then search actively for alarm symptoms of potentially serious diseases (cancer, infection; “red flags”) on the one hand, and of functional and/or mental disturbances (“yellow flags”) on the other. Red flags, though not very sensitive, are highly specific for organic disease (Box 3).
The absence of red flags, a normal physical examination, and the presence of yellow flags (Table 2) support the provisional diagnosis of a functional bowel disorder.
Further tests for the exclusion of somatic disease, particularly ileocolonoscopy, should be considered on a case-to-case basis. For younger persons (under age 40) in particular, a trial of treatment for a provisional diagnosis of IBS may be worthwhile (12). Ileocolonoscopy and, in some cases, targeted testing for the exclusion of particular diseases are an obligatory part of the diagnostic assessment of IBS (12).
Further diagnostic evaluation
Any additional diagnostic tests that are to be carried out should be discussed with the patient first. It is important to inform the patient that these tests are very unlikely to reveal a serious illness, and that they are simply being performed to rule such illnesses out (Box 4) (15).
Special diagnostic testing
Special diagnostic tests are carried out depending on the patient’s main symptoms (Box 5) (12).
Diagnostic studies that are not recommended
The measurement of IgG titers to food allergens and of quantitative parameters of the stool flora (e.g., an “intestinal ecogram”) is not recommended (12).
What to do about pathological findings
The more tests one performs, the more likely it becomes that positive findings will arise. Faulty communication of the findings can precipitate or worsen the patient’s fear of disease and inappropriate illness behavior (e.g., phobic eating behavior). In interpreting the H2 breath test, for instance, the physician must bear in mind that the quantities consumed in a typical test are greater than those typically eaten by human beings in everyday life: 50 g of lactose are contained in a liter of milk and 50 g of fructose in about 500 g (more than one pound) of bananas or cherries (19). Such tests yield useful information only when the rise in H2 is accompanied by typical symptoms (12). The potential significance of an abnormal and symptomatic H2 breath test for the overall complex of symptoms should be carefully explained to the patient.
A psychotherapeutic diagnostic evaluation by a specialist is recommended for patients with severe functional bowel disorders (Box 1). This evaluation consists of the taking of a biographical history and the structured assessment of potential psychological comorbidities (15).
All patients with IBS undergo basic treatment, and some (depending on the severity and main symptoms of their IBS) go on to receive additional treatment as well.
The basic treatment consists of the provision of extensive information to the patient. The physician should describe the patient’s symptoms in a positive way (positive communication of the diagnosis); some key words for this are “irritable bowel,” “sensitive bowel,” and “functional bowel disorder.” Moreover, the physician should make it clear to the patient in this discussion that he or she considers the symptoms genuine. The following things should be communicated to the patient:
- the fact that persons with functional bowel disorders have a normal life expectancy
- a biopsychosocial model of the disorder, e.g., a stress or vicious-circle model
- the need for a proper amount of physical exercise (endurance sports) (e9) and for strengthening personal resources (hobbies, social contacts)
- the need to set realistic goals for treatment, such as the following, because functional disorders are rarely fully curable:
– improvement, rather than elimination, of symptoms
– learning ways to improve self-management and quality of life
– understanding that no treatment is effective against every symptom in every patient.
An intensive, empathetic physician-patient relationship is the essential basis for such discussions (22).
Patients whose symptoms interfere with their everyday life should discuss potential further treatments with the physician and reach a joint decision whether to undergo them. Pharmacotherapy and psychotherapy are rather ineffective treatments for functional bowel symptoms by the standards of evidence-based medicine, yet they do produce impressive results in individual cases. When choosing among the therapeutic options, the physician should bear individual factors in mind, including the pattern and severity of symptoms, the patient’s personality structure and preferences, the physician’s own expertise, and the availability of various kinds of treatment (medications, appointments for psychotherapy).
If the clinical history implies the symptoms may be related to food, the patient should keep a diary of food intake and symptoms for a limited period of time. Patients with symptoms of irritable bowel syndrome who are found to suffer from carbohydrate malabsorption (e.g., of lactose, fructose, or sorbitol) should undertake a trial diet with reduced amounts of the substance in question for at least 14 days. Dietary measures of any type should be maintained over the long term only if they clearly improve the patient’s symptoms (grade of recommendation B). Eliminatory diets should be accompanied by follow-up checks to avoid malnutrition (12). In a randomized controlled trial on 150 patients, an eliminatory diet that was drawn up on the basis of IgG 4 values against 29 different kinds of food was compared with a sham eliminatory diet. No difference was found between the two diets with respect to the improvement of bowel-related symptoms (e10).
Abdominal pain in functional bowel disorders should be treated primarily with spasmolytics (EL 1a). Milder symptoms can be treated with soluble bulking agents (psyllium) and probiotics, alone or in combination (EL 1a). Drugs to be avoided include peripherally active analgesics (ASA, NSAID) (EL 5), paracetamol (EL 2b), and opioid agonists (EL 1a for κ-agonists, EL 4 for μ-agonists and classic opiates, EL 1a for opiate antagonists) (Box 6 und eTable 2).
Loperamide is usually effective against diarrhea and stool urgency (EL 1a). It can be used over the long term (years), because it is not systemically bioavailable. Bulking agents (EL 1a) and probiotics (EL 1a) can be used instead of loperamide or in combination with it. For spastic diarrhea, spasmolytic agents have been shown to be helpful (EL 1a). Severe, otherwise intractable diarrhea that markedly impairs the patient’s quality of life may respond to a trial of a serotonin-3 antagonist (alosetron is approved in the USA for this indication, but only in women); the medication may simultaneously relieve the associated pain (EL 2a) (23).
Constipation should be treated with due attention to the different forms that it can take. Most often, patients express dissatisfacton with the consistency of their stool and the effort required to defecate, or they complain of a sensation of incomplete emptying afterward. Measurements in such patients reveal a normal passage of stool through the colon. In this situation, bulking agents in the form of water-soluble gel formants, such as psyllium (EL 1a), can be given as treatment. Other bulking agents, such as wheat bran or lactulose, are also effective against constipation, but their common side effects, including bloating and cramping abdominal pain, often lead to a net worsening of symptoms. Alternatively, osmotic laxatives of the macrogol type (EL 2a) and probiotics (EL 1a) can be tried. For the subtype of spastic, painful constipation, spasmolytics have been shown to be effective (EL 1a) (eTable 2).
Constipation must be differentiated from a bowel-emptying disturbance by specific questioning of the patient (“Do you have to press hard?”). Emptying disturbances require a further work-up that begins with a functional clinical examination, possibly acompanied by functional proctoscopy. If this reveals no definite evidence of an organic abnormality (e.g., a fissure or prolapse), then the emptying disturbance should be treated with psyllium and controlled bowel emptying, e.g., through the use of CO2-releasing suppositories (EL 5).
In rare cases, there may be a genuine prolongation of the colon transit time. Bisacodyl, sodium picosulfate, and senna preparations are indicated for the treatment of this condition (EL 1a). A new treatment is with serotonergic substances, such as the intestinally active prokinetic agent prucalopride (EL 1a) (eTable 3).
Bloating symptoms (meteorism, distention, flatulence) arise through different mechanisms in constipation and diarrhea. Only a small number of clinical studies have dealt with the treatment of bloating symptoms per se. The successful treatment of constipation and diarrhea can improve bloating as well. Another therapeutic approach is to treat the enteric flora, either with probiotics (EL 1a) or with the non-resorbable antibiotic rifaximine (EL 2a) (24). No data are available on the possible efficacy of defoaming agents (simethicone, dimethicone) in irritable bowel syndrome, but these can be given on a trial basis, as they have been found useful in the treatment of dyspepsia and acute enteritis.
In summary, the efficacy of drugs used to treat irritable bowel syndrome is hard to prove in view of the heterogeneity and variability of symptom patterns, as well as the high placebo response rates. There is no evidence of a therapeutic benefit persisting after the cessation of treatment. The trial use of a drug should be terminated in three months at most if no benefit has been obtained (12).
- Gut-directed hypnosis
- Relaxation techniques (autogenic raining)
- Interpersonal/psychodynamic therapy
- Cognitive behavioral therapy, stress management.
25 randomized clinical trials of psychological techniques were analyzed in a Cochrane review of the relevant literature up to 2008. The psychological techniques were found to lead to a greater reduction of symptoms at the end of treatment than either symptomatic drug treatment or no treatment at all (placement on a waiting list) (25). These techniques enable patients to manage their symptoms themselves, independently, over the long term. For gut-directed hypnosis, follow-up studies are available for periods of up to 5 years (without a control group) and reveal a persistent reduction of symptoms in half of all patients (e11). In two recent trials, the treatment group had a sustained reduction of symptoms at one year in comparison to the control group (either supportive treatment or placement on a waiting list) (e12).
Methods of complementary medicine
Many patients use complementary or alternative therapies. A glance at patient-forum websites and Internet offerings reveals that such treatments are heavily advertised and widely used. Data on efficacy are nonexistent or controversial for homeopathy, traditional Chinese medicine, acupuncture, qi gong, meditation, tai chi, and aloe vera (12–14, e13, e14).
The efficacy of the following treatments has not been documented in controlled trials and must therefore be doubted: antifungal drugs and supposedly antifungal diets for patients who have been found to have Candida albicans in their stool; intestinal lavage; rectal ozone insufflation; and so-called detoxification therapy (12).
For most patients with functional bowel disorders, care by a primary care physician or a gastroenterologist is the central form of treatment, or indeed the only practical one. Physicians who care for such patients should ideally be well versed in the basic management of psychosomatic disorders. In severe cases, the treatment should be accompanied by specialized psychotherapy; the psychotherapeutic consultation should be discussed with the patient and then initiated by the treating primary care physician or gastroenterologist. Interdisciplinary, multimodal treatment is advisable for severe and chronic cases (15).
Conflict of interest statement
PD Dr. Häuser has received reimbursement of meeting participation fees and of travel and accomodation expenses from Eli Lilly and the Falk Foundation. He has received honoraria for the preparation of scientific continuing education events from Eli Lilly, the Falk Foundation, Mundipharma, Janssen-Cilag, and Pfizer.
Prof. Layer has received consulting fees from Abbott, Solvay, Shire, and Norgine. He has received reimbursement of travel and accommodation expenses from Shire and Norgine. He has received honoraria for the preparation of scientific continuing education events from Falk, Shire, Norgine, Abbott, Axcan, Boehringer, and Novartis. He has received payment for the performance of clinical trials on behalf of Axcan and Solvay.
Prof. Henningsen has received honoraria for the preparation of scientific continuing education events from Lilly.
Prof. Kruis serves as a consultant for Ardeypharm and Shire. He has received honoraria for the preparation of scientific continuing education events from Ardeypharm and Shire.He has also received payment for the performance of clinical trials on behalf of these two companies, as well as financial support from them for a research project that he initiated.
Manuscript submitted on 30 July 2011, revised version accepted on
22 November 2011.
Translated from the original German by Ethan Taub, M.D.
Prof. Dr. med. Wolfgang Kruis
Abteilung für Innere Medizin des Evangelischen Krankenhauses Kalk
Universität zu Köln
Buchforststr. 2, 51103 Cologne, Germany
@For eReferences please refer to:
eTables available at:
Z Gastroenterol 2008; 46: 279–91. MEDLINE
Medizinische Klinik, Israelitisches Krankenhaus Hamburg: Prof. Dr. med. Layer
Klinik für Psychosomatische Medizin und Psychotherapie, Technische Universität München: Prof. Dr. med. Henningsen
Abteilung für Innere Medizin des Evangelischen Krankenhauses Kalk,
Universität Köln: Prof. Dr. med. Kruis
|1.||Hiller W, Rief W, Brähler E: Somatization in the population: from mild bodily misperceptions to disabling symptoms. Soc Psychiatry Psychiatr Epidemiol 2006; 41: 704–12. CrossRef MEDLINE|
|2.||Oberndorff-Klein Woolthuis AH, Brummer RJ, de Wit NJ, Muris JW, Stockbrügger RW: Irritable bowel syndrome in general practice: an overview. Scand J Gastroenterol Suppl 2004; 241: 17–22. CrossRef MEDLINE|
|3.||Thompson WG, Heaton KW, Smyth GT, Smyth C: Irritable bowel syndrome in general practice: prevalence, characteristics, and referral. Gut 2000; 46: 78–82. CrossRef MEDLINE|
|4.||Dhaliwal SK, Hunt RH: Doctor-patient interaction for irritable bowel syndrome in primary care: a systematic perspective. Eur J Gastroenterol Hepatol 2004; 16: 1161–6. CrossRef MEDLINE|
|5.||Spiegel BM, Farid M, Esrailian E, Talley J, Chang L: Is irritable bowel syndrome a diagnosis of exclusion?: a survey of primary care providers, gastroenterologists, and IBS experts. Am J Gastroenterol 2010; 105: 848–58. CrossRef MEDLINE|
|6.||Müller-Lissner SA, Pirk O: Irritable bowel syndrome in Germany. A cost of illness study. Eur J Gastroenterol Hepatol 2002; 14: 1325–9. CrossRef MEDLINE|
|7.||Tack J, Talley NJ, Camilleri M, Holtmann G, Hu P, Malagelada JR, Stanghellini V: Functional gastroduodenal disorders. Gastroenterology 2006; 130: 1466–79. CrossRef MEDLINE|
|8.||Behar J, Corazziari E, Guelrud M, Hogan W, Sherman S, Toouli J: Functional gallbladder and sphincter of oddi disorders. Gastroenterology 2006; 130: 1498–509. CrossRef MEDLINE|
|9.||Bharucha AE, Wald A, Enck P, Rao S: Functional anorectal disorders. Gastroenterology 2006; 130: 1510–8. CrossRef MEDLINE|
|10.||Bufler P, Gross M, Uhlig HH: Recurrent abdominal pain in childhood. Dtsch Arztebl Int 2011; 108(17): 295–304. VOLLTEXT|
|11.||Longstreth GF, Thompson WG, Chey WD, Houghton LA, Mearin F, Spiller RC. Functional bowel disorders. Gastroenterology 2006; 130: 1480–91. CrossRef MEDLINE|
|12.||Layer P, Andresen V, Pehl C, Allescher H, Bischoff SC, Classen M, et al.: Irritable bowel syndrome: German consensus guidelines on definition, pathophysiology and management. Z Gastroenterol 2011; 49: 237–93. CrossRef MEDLINE|
|13.||Spiller R, Aziz Q, Creed F, Emmanuel A, Houghton L, Hungin P, et al.: Guidelines on the irritable bowel syndrome: mechanisms and practical management. Gut 2007; 56: 1770–98. CrossRef MEDLINE|
|14.||American College of Gastroenterology Task Force on Irritable Bowel Syndrome, Brandt LJ, Chey WD, Foxx-Orenstein AE, Schiller LR, Schoenfeld PS, et al.: An evidence-based position statement on the management of irritable bowel syndrome. Am J Gastroenterol 2009; 104(Suppl 1): 1–35. MEDLINE|
|15.||Hausteiner-Wiehle C, Sattel H, Ronel J, Schäfert R, Herrmann M, Häuser W, Henningsen P (Steuerungsgruppe): Interdisziplinäre S3-Leitlinie zum Umgang mit Patienten mit nicht-spezifischen, funktionellen und somatoformen Körperbeschwerden. AWMF 2012; in press.|
|16.||Tanaka Y, Kanazawa M, Fukudo S, Drossman DA: Biopsychosocial model of irritable bowel syndrome. J Neurogastroenterol Motil 2011; 17: 131–9. CrossRef MEDLINE|
|17.||Kato K, Sullivan PF, Evengård B, Pedersen NL: A population-based twin study of functional somatic syndromes. Psychol Med 2009; 39: 497–505. CrossRef MEDLINE|
|18.||Saito YA: The role of genetics in IBS. Gastroenterol Clin North Am 2011; 40: 45–67. CrossRef MEDLINE|
|19.||Wächtershäuser A, Stein JM: Nutritional factors and nutritional therapy for irritable bowel syndrome—what is worthwhile? |
Z Gastroenterol 2008; 46: 279–91. MEDLINE
|20.||Chang L: The role of stress on physiologic responses and clinical symptoms in irritable bowel syndrome. Gastroenterology 2011; 140: 761–5. CrossRef MEDLINE|
|21.||Nicholl BI, Halder SL, Macfarlane GJ, Thompson DG, O’Brien S, Musleh M, McBeth J: Psychosocial risk markers for new onset irritable bowel syndrome—results of a large prospective population-based study. Pain 2008; 137: 147–55. CrossRef MEDLINE|
|22.||Spiegel BM, Naliboff B, Mayer E, Bolus R, Gralnek I, Shekelle E: The effectiveness of a model physician-patient relationship versus usual care in irritable bowel syndrome (IBS): A randomized controlled trial Gastroenterology 2006; 130: Suppl 2: A–112.|
|23.||Andresen V, Montori VM, Keller J, West CP, Layer P, Camilleri M: Effects of 5-hydroxytryptamine (serotonin) type 3 antagonists on symptom relief and constipation in nonconstipated irritable bowel syndrome: a systematic review and meta-analysis of randomized controlled trials. Clin Gastroenterol Hepatol 2008; 6: 545–55. CrossRef MEDLINE|
|24.||Pimentel M, Lembo A, Chey WD, et al.: TARGET Study Group: Rifaximin therapy for patients with irritable bowel syndrome without constipation. N Engl J Med 2011; 364: 22–32. CrossRef MEDLINE|
|25.||Zijdenbos IL, de Wit NJ, van der Heijden GJ, Rubin G, Quartero AO: Psychological treatments for the management of irritable bowel syndrome. Cochrane Database Syst Rev 2009 21; (1): CD006442. MEDLINE|
|e1.||Andresen V, Keller J, Pehl C, Schemann M, Preiss J, Layer P: Clinical practice guideline: Irritable bowel syndrome–the main recommendations. Dtsch Arztebl Int 2011; 108(44): 751–60.|
|e2.||Henningsen P, Zipfel S, Herzog W: Management of functional somatic syndromes. Lancet 2007; 369: 946–55.|
|e3.||Häuser W, Eich W, Herrmann M, Nutzinger DO, Schiltenwolf M, Henningsen P: Fibromyalgia syndrome: classification, diagnosis, and treatment. Dtsch Arztebl Int 2009; 106(23): 383–91.|
|e4.||Janssen HA, Muris JW, Knotterus JA: The clinical course and prognostic determinants of the irritable bowel syndrome: a literature review. Scand J Gastroenterol 1998; 33: 561–7.|
|e5.||Schwille-Kiuntke J, Frick JS, Zanger P, Enck P: Post-infectious irritable bowel syndrome—a review of the literature. Z Gastroenterol 2011; 49: 997–1003.|
|e6.||Spiller R, Garsed K: Postinfectious irritable bowel syndrome. Gastroenterology 2009; 136: 1979–88.|
|e7.||Levy RL, Whitehead WE, Walker LS, Von Korff M, Feld AD, Garner M, Christie D: Increased somatic complaints and health-care utilization in children: effects of parent IBS status and parent response to gastrointestinal symptoms. Am J Gastroenterol 2004; 99: 2442–51.|
|e8.||Paras ML, Murad MH, Chen LP, et al.: Sexual abuse and lifetime diagnosis of somatic disorders: a systematic review and meta-analysis. JAMA 2009; 302: 550–61.|
|e9.||Johannesson E, Simrén M, Strid H, Bajor A, Sadik R: Physical activity improves symptoms in irritable bowel syndrome: a randomized controlled trial. Am J Gastroenterol 2011; 106: 915–22.|
|e10.||Atkinson W, Sheldon TA, Shaath N, Whorwell PJ: Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial. Gut 2004; 53: 1459–64.|
|e11.||Hefner J, Rilk A, Herbert BM, Zipfel S, Enck P, Martens U: Hypnotherapy for irritable bowel syndrome-a systematic review. Z Gastroenterol 2009; 47: 1153–9.|
|e12.||Lindfors P, Unge P, Arvidsson P, et al.: Effects of Gut-Directed Hypnotherapy on IBS in Different Clinical Settings-Results From Two Randomized, Controlled Trials. Am J Gastroenterol 2011 Oct 4. doi: 10.1038/ajg.2011.340 [Epub ahead of print].|
|e13.||Lim B, Manheimer E, Lao L, et al.: Acupuncture for treatment of irritable bowel syndrome. Cochrane Database Syst Rev 2006 18; (4): CD005111 e12=e13|
|e14.||Liu JP, Yang M, Liu YX, Wei ML, Grimsgaard S: Herbal medicines for treatment f irritable bowel syndrome. Cochrane Database Syst Rev 2006 J 25; (1): CD004116 [Epub ahead of print].|
|e15.||Ford AC, Talley NJ, Spiegel BM, et al.: Effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome: systematic review and meta-analysis. BMJ 2008 13; 337: a2313. doi: 10.1136/bmj.a2313.|
|e16.||Moayyedi P, Ford AC, Talley NJ, et al.: The efficacy of probiotics in the treatment of irritable bowel syndrome: a systematic review. Gut 2010; 59: 325–32.|
|e17.||Ford AC, Talley NJ, Schoenfeld PS, Quigley EM, Moayyedi P: Efficacy of antidepressants and psychological therapies in irritable bowel syndrome: systematic review and meta-analysis. Gut 2009; 58: 367–7.|
|e18.||Suares NC, Ford AC: Systematic review: the effects of fibre in the management of chronic idiopathic constipation. Aliment Pharmacol Ther 2011; 33: 895–901.|
|e19.||Ford AC, Suares NC: Effect of laxatives and pharmacological therapies in chronic idiopathic constipation: systematic review and meta-analysis. Gut 2011; 60: 209–18.|