Abstract
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.
The frequency of functional bowel disorders.
Half of all adults who suffer from chronic abdominal pain and stool irregularity have functional bowel disorders.
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).
Learning objectives
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.
Definition.
By definition, functional bowel disorders are characterized by a typical constellation of symptoms, a defined duration (at least 3 months), and the exclusion of other diseases that could adequately account for the symptoms.
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).
Classification (according to “Rome III”).
Irritable bowel syndrome
Functional bloating
Functional constipation
Functional diarrhea
Functional bowel disorder, not otherwise specified
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).
Life expectancy.
Functional bowel disorders do not elevate the risk of bodily disease. Persons with functional bowel disorders have a normal life expectancy.
Etiology.
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 and to their provocation and chronification.
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).
Table 1. Clinical features of milder and more severe cases of functional bowel disorder (these are not obligate criteria, as there are many transitional cases)*1.
| Criteria | Mild course | Severe course |
| Physical symptoms | Mainly bowel-related symptoms | Multiple symptoms affecting not only the bowel, but also other organs and the body as a whole |
| Temporal course of physical symptoms | Recurrent, with symptom-free periods in between | Persistent |
| Emotional symptoms | Mild | Severe |
| Subjective theory of disease | Appropriate (e.g., attribution to stress or types of food) | Inappropriate(e.g., persistent fear of serious illness despite diagnostic exclusion) |
| Subjective degree of impairment (work, family, leisure time) | Low or none | High |
| Utilization of medical services | Low | High (doctor shopping) |
| Psychosocial stressors | Few and mild (family, work) | Numerous and/or severe (family, work) |
| Physician-patient relationship | Cooperative | “Difficult,” frustrating |
*1(modified from 15, e2)
The following classification is helpful in assessing the patient’s need for treatment (15, e2):
“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.
Diagnostic criteria.
Presence of a typical complex of symptoms for at least 3 months (positive criteria)
Exclusion of other possible diagnoses by a well-defined battery of tests
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).
Biological factors
The biological factors include a possible genetic predisposition, previous gastrointestinal infections, and food intolerance.
Diagnostic testing to exclude other diseases.
This is performed in multiple steps: basic diagnostic evaluation (obligatory) and special diagnostic evaluation (not obligatory in all cases; depending on the pattern and severity of symptoms, as well as on the patient’s age).
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).
eTable 3. The efficacy of selected medications for chronic idiopathic constipation.
| Reference | Treatment vs. control | Number of studies / of patients | Target variable | Statistical measures of efficacy (95% confidence interval) | Number needed to treat (95% confidence interval) |
| e18 | Bulking agents vs. placebo | 6/364 | Global symptomatic improvement, number of stools per week | 86.5% vs. 28.6% 3.8 vs. 2.9 | Not reported |
| e19 | Osmotic laxatives vs. placebo | 6/676 | Relative risk (RR) of treatment failure;weighted mean difference (WMD) | RR 0.50 (0.39–0.63) WMD 2.51 (1.30–3.71) | 3 (2–4) |
| e19 | Secretory laxatives vs. placebo | 2/735 | Relative risk (RR) of treatment failure;weighted mean difference (WMD) | RR 0.54 (0.42–0.69) WMD 2.50 (0.93–4.07) | 3 (2–3.5) |
| e19 | Prucalopride vs. placebo | 7/2639 | Relative risk (RR) of treatment failure;weighted mean difference (WMD) | 0.82 (0.76–0.88) No data | 6 (5–9) |
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).
Psychological factors
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).
Simultaneous biopsychosocial diagnostic assessment.
At every step of the diagnostic evaluation, the potential somatic and psychosocial disease factors should be assessed simultaneously.
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).
Stress: Stressful life events and chronic psychosocial stress increase the risk of postinfectious IBS (cf. eTable 1) and worsen the symptoms of IBS that is already present (13, 16).
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).
Pathophysiological mechanisms
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:
Box 1. Pathophysiological mechanisms of irritable bowel syndrome (12–14 16, 17).
Disturbances of visceral motility
-
Visceral hypersensitivity
peripheral sensitization
central sensitization
Disturbances of the hypothalamic-pituitary-adrenocortical axis
Disturbances of the autonomic and enteric nervous system
Disturbances of the intestinal flora and intestinal permeability
Postinfectious cellular changes (e.g., increased number of mast cells and intraepithelial lymphocytes)
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).
Communication of the diagnosis.
The symptoms should be described in a positive way, and the legitimacy of the patient’s complaints should be recognized.
Diagnostic evaluation
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).
Box 2. Basic diagnostic evaluation of chronic bowel symptoms.
-
Thorough history-taking
description of symptoms in the patient’s own words
directed questioning about somatic and psychosocial warning signs
Physical examination, including rectal examination
-
Basic laboratory profile:
complete blood count
erythrocyte sedimentation rate (ESR),
C-reactive protein (CRP)
urinalysis
Abdominal ultrasonography
Gynecological examination for women
Psychosocial screening
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). Ultrasonography is part of the basic diagnostic assessment of abdominal symptoms. In women, gynecological causes (endometriosis, adnexitis, ovarian cysts, ovarian carcinoma) should be ruled out through an examination by a gynecologist (12).
Box 3. Warning signs (“red flags”) for somatic causes of disease.
Diarrhea as the main symptom
Fever
Blood in the stool
Weight loss of more than 10% despite unchanged food intake
Nocturnal symptoms
Family history of colon cancer
Onset of symptoms after age 50
Brief history (<6–12 months) and/or progressive symptoms
In the basic laboratory profile: anemia, signs of inflammation
Red flags, yellow flags.
The absence of red flags, a normal physical examination, and the presence of yellow flags support the provisional diagnosis of a functional bowel disorder.
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. Screening questions about impairment in everyday life (“How do the symptoms affect your everyday life/your performance?”) and the patient’s current emotional state (“Have you often felt depressed in the past month? Have you often felt anxious or nervous in the past month?”) are recommended (13, 15). Patients’ descriptions of further somatic and psychological symptoms and of major impairment in everyday activities are predictors of a more severe course of disease.
Table 2. “Yellow flags” in the initial clinical history pointing toward bowel symptoms of structural and functional origin (modified from 15).
| Item of history | Structural origin of symptoms | Functional origin of symptoms |
| Symptom duration | Short | Long |
| Symptom development | Progressivelysevere | Periods with mild symptoms or none |
| Symptoms elsewhere in the body | None | Present (with variable severity) |
| Emotional symptoms | Usually none | Commonly present (with variable severity) |
| Type of descriptionof symptoms | Matter-of-fact, perhaps with minimizing tendency | Variably severe affective involvement (evident suffering) |
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).
Box 4. Further diagnostic assessment: more diagnostic tests to be applied on an ndividual basis (12).
- Serum electrolytes, renal function tests, hepatic and pancreatic enzymes
Basal TSH
Fasting blood sugar / HbA1c
Microbiological examination of the stool (mainly for patients with diarrhea)
Sprue antibodies (transglutaminase antibodies)
Calprotectin A / lactoferrin in the stool
Ileocolonoscopy for patients over age 50, for patients over age 45 with a family history of colon cancer, and for patients of any age with elevated levels of calprotectin A / lactoferrin in the stool)
Further psychosocial exploration: stressors (work, family), fear of disease (e.g., of cancer)
Special diagnostic testing
Special diagnostic tests are carried out depending on the patient’s main symptoms (Box 5) (12). For example, patients with chronic diarrhea should be tested for treatable causes, such as microscopic/collagenous colitis, celiac disease, chronic inflammatory bowel diseases, giardiasis, lactose or fructose malabsorption, and bile acid malabsorption. Ileocolonoscopy is obligatory.
Box 5. Special diagnostic testing depending on the main symptoms (12).
-
Main symptom: diarrhea
further search for pathogens in stool (e.g., lamblia, worm eggs)
ileocolonoscopy with stepwise biopsies
esophagogastroduodenoscopy with duodenal biopsies
lactose, fructose, and sorbitol H2 breath test
selenium-75-homotaurocholic acid test (SEHCAT)
-
Main symptom: severe constipation
measurement of the colon transit time (and further testing if the colon transit time is delayed or if an anorectal obstruction is found)
-
Main symptom: bloating
glucose H2 breath test (evidence of abnormal bacterial colonization?)
lactose, fructose, and sorbitol H2 breath test
GI series (plain films or MRI) (stenosis?)
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).
Special diagnostic tests….
... are performed depending on the patient’s main complaints. Ileocolonoscopy is obligatory.
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.
Psychotherapeutic evaluation
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).
Treatment
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.
Basic treatment
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).
Basic treatment.
Basic treatment consists of the conclusive establishment and persuasive communication of the diagnosis, followed by encouragement of the patient to take regular exercise.
Further treatments
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).
Dietary measures
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).
Pharmacotherapy
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).
Box 6. Pharmacotherapy for functional bowel disorders (grade of recommendation)*1.
-
Bloating / abdominal distention / flatulence
defoaming agents (C)
phytotherapeutic agents (B)
probiotics (Bifidobacterium infantis 35624, Bifidobacterium animalis DN173010, Lactobacillus casei Shirota) (B)
rifaximine (A)
-
Diarrhea
bulking agents (B)
cholestyramine (C)
5-HT3 antagonists (alosetrone) (A)
loperamide (A)
probiotics (A)
-
Constipation
antidepressants from the class of serotonin reuptake inhibitors (B)
bulking agents (A)
5-HT4 agonists (prucalopride) (B)
osmotic laxatives (macrogol B, others C)
probiotics (combined preparations such as Lactobacillus casei Shirota, Bifidobacterium animalis DN173010, E. coli Nissle 1917) (A)
Phytotherapeutic agents (A)
-
Pain
Antidepressants: either tricyclic antidepressants or serotonin reuptake inhibitors (A)
phytotherapeutic agents (A)
probiotics (combined preparations, e.g., VSL#3) (A)
spasmolytic agents (A)
-
Stool irregularity
phytotherapeutic agents (A)
spasmolytic agents (A)
*1alphabetical order; grades of recommendation according to (12)
eTable 2. The efficacy of selected medications and psychotherapeutic techniques in the treatment of irritable bowel syndrome.
| Reference | Treatment vs. control | Number of studies / of patients | Target variable | Relative risk (95% confidence interval) | Number needed to treat (95% confidence interval) |
| e15 | Psyllium vs. placebo | 12/541 | Persistent bowel-related symptoms | 0.78 (0.63–0.96) | 6 (3–50) |
| e15 | Bran vs. placebo | 5/221 | Persistent bowel-related symptoms | 1.02 (0.82–1.27) | not reported |
| e15 | Mebeverine vs. placebo | 1/80 | Persistent bowel-related symptoms | 1.25 (0.99–1.58) | not reported |
| e15 | Peppermint oil vs. placebo | 6/321 | Persistent bowel-related symptoms | 0.43 (0.32–0.59) | 2.5 (2–3) |
| e16 | Probiotics vs. placebo | 10/918 | Persistent bowel-related symptoms | 0.71 (0.57–0.88) | 4 (3–12.5) |
| e17 | Tricyclic antidepressants vs. placebo | 9/575 | Persistent bowel-related symptoms | 0.68 (0.56–0.83) | 4 (3–8) |
| e17 | Serotonin reuptake inhibitors vs. placebo | 5/230 | Persistent bowel-related symptoms | 0.62 (0.45–0.87) | 3.5 (2–14) |
| e17 | Cognitive behavioral therapy vs. usual treatment | 7/491 | Persistent bowel-related symptoms | 0.59 (0.42–0.87) | 3 (2–7) |
| e17 | Relaxation training vs. usual treatment | 5/234 | Persistent bowel-related symptoms | 0.82 (0.63–1.08) | not reported |
| e17 | Gut-directed hypnosis vs. usual treatment | 2/40 | Persistent bowel-related symptoms | 0.48 (0.26–0.87) | 2 (1.5–7) |
| e17 | Psychodynamic therapy vs. usual treatment | 3/211 | Persistent bowel-related symptoms | 0.60 (0.39–0.93) | 3.5 (2–25) |
Treatment goals.
Patients should be instructed to set attainable goals for their treatment:
Improved quality of life
Improvement (not elimination) of symptoms
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).
Pharmacotherapy.
Treatment with drugs for a limited time only (4–12 weeks) can be carried out depending on the patient’s main symptoms.
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).
Psychotherapy.
Gut-directed hypnosis, relaxation techniques, interpersonal/psychodynamic therapy, and cognitive behavioral therapy can improve the symptoms of irritable bowel syndrome.
Psychotherapeutic methods
The following psychotherapeutic methods are recommended in the IBS guidelines (12–14) (all EL 1a) (eTable 2):
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).
Conclusion
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).
Pharmacotherapy.
The efficacy of any drug against irritable bowel syndrome is difficult to prove, because of the heterogeneity and variability of symptom patterns as well as the high rates of response to placebo.
Recommended psychotherapeutic techniques.
Gut-directed hypnosis
Relaxation techniques (autogenic training)
Interpersonal/psychodynamic therapy
Cognitive behavioral therapy, stress management
Treatment of cases with a severe course.
Cases that take a severe course should be treated multimodally with the cooperation of the family physician, gastroenterologist, and psychotherapist.
Further Information on CME.
This article has been certified by the North Rhine Academy for Postgraduate and Continuing Medical Education. Deutsches Ärzteblatt provides certified continuing medical education (CME) in accordance with the requirements of the Medical Associations of the German federal states (Länder). CME points of the Medical Associations can be acquired only through the Internet, not by mail or fax, by the use of the German version of the CME questionnaire within 6 weeks of publication of the article. See the following website: cme.aerzteblatt.de
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For issue 9/2012, we plan to offer the topic “Cancer-Related Fatigue.”
Solutions to the CME questionnaire in issue 49/2011:
Schommer K, Bärtsch P: Basic Medical Advice for Travelers to High Altitudes.
Solutions: 1c, 2d, 3a, 4e, 5c, 6d, 7a, 8e, 9d, 10a
Please answer the following questions to participate in our certified Continuing Medical Education program.Only one answer is possible per question. Please select the answer that is most appropriate.
Question 1
In primary care, what percentage of persons evaluated for chronic (>3 months) abdominal pain and bowel irregularity ultimately receive the diagnosis of a functional bowel disorder?
5%
10%
20%
30%
50%
Question 2
According to the current criteria of the German guideline on irritable bowel syndrome, what constellation of symptoms characterizes this most important of all functional bowel disorders?
Bowel symptoms for at least two months and at least four days a week
Bowel symptoms for at least three months and at least three days a week
Bowel symptoms every day for a month
Bowel symptoms for at least three months with a significant impairment of quality of life
Bowel symptoms for at least six months, and for at least three days per month in the last three months
Question 3
In patients with chronic bowel complaints, which of the following items in the history points toward a functional disorder?
Fever
Rectal bleeding
>10% weight loss with unchanged food intake
Many other physical and psychological complaints
Abdominal pain at night
Question 4
A 40-year-old woman with an established diagnosis of irritable bowel syndrome (main symptoms: abdominal pain and bloating) has an abnormal lactose-H2 breath test and tries a lactose-free diet for 14 days. Her symptoms do not change. According to the guidelines, how should she be treated?
Continuation of the lactose-free diet for at least three more months
Acupuncture
Rectal ozone insufflation
Treatment with a probiotic
Psychoanalysis
Question 5
A 30-year-old man complains to his family physician for recurrent abdominal pain and stool irregularity for one year. Which of the following is part of the basic diagnostic assessment?
Computerized tomography of the abdomen
Hepatic and pancreatic enzymes
Microbiological examination of the stool
Complete blood count
Sprue antibodies
Question 6
Which of the following procedures is an obligate part of the diagnostic evaluation of watery diarrhea?
Ileocolonoscopy with stepwise biopsies
Colon transit time
Anorectal manometry
Capsule endoscopy of the small bowel
IgG4 titer for food allergens
Question 7
Which of the following is often associated with irritable bowel syndrome?
IgE-mediated food allergies
Anxiety disorders
Candida colonization of the large bowel
Abnormal bacterial colonization of the small bowel
Helicobacter pylori infection
Question 8
Which of the following is part of the basic treatment of functional bowel disorders?
Symptomatic medication
Positive communication of the diagnosis: “You have irritable bowel syndrome.”
An eliminatory diet
Acupuncture
Cognitive behavioral therapy
Question 9
What psychotherapeutic technique has been shown to improve some patients’ symptoms?
Psychoanalysis
Talk therapy as described by Rogers
Gut-directed hypnosis
Systematic family therapy
Biofeedback
Question 10
What medication do the guidelines recommend for the treatment of diarrhea in irritable bowel syndrome?
Loperamide
Fluoxetine (a serotonin reuptake inhibitor)
Prucalopride (a 5-HT4 agonist)
A peppermint oil preparation
Nystatin (an antifungal agent)
eTable 1. Risk indicators for the development of postinfectious irritable bowel syndrome (prospective cohort studies) (e6).
| Risk indicator | Relative risk (RR) / Odds ratio (OR), (95% confidence interval) |
| Gastroenteritis >3 weeks | RR 11.4 (2.2–58) |
| Smoking | OR 4.8 (1.5–15.2) |
| Traveler’s diarrhea treated with antibiotics | RR 4.1 (1.1–15.3) |
| Depression | RR 3.2 (not reported) |
| Female sex | RR 2.4 (1.2–40) |
| Hypochondriasis | RR 2. 0 (1.8–2.5) |
| Stressful life events in the 3 months preceding GI infection | RR 2.0 (1.7–2.4) |
| Anxiety | RR 1.8 (1.1–12.2) |
| Age >60 years | RR 0.4 (0.1–0.02) |
Acknowledgments
Translated from the original German by Ethan Taub, M.D.
Footnotes
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.
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