The irritable bowel syndrome and psychiatric disorders in the community: is there a link?

Irritable bowel syndrome: epidemiology, natural history, health care seeking and emerging risk factors

IBS is a common condition, affecting approximately 3% to 15% of the general population based on various diagnostic criteria. There seem to be differences in disease epidemiology between the eastern and the western world. As data from larger Asian epidemiological studies begin to surface,however, such differences appear to be less marked. The proportion of IBS patients who consult a physician for their symptoms is around 50%. Psychological factors and the presence and duration of abdominal pain are all significant predictors for health care seeking. The natural history of IBS is characterized by frequent fluctuation of symptoms and by an overlap with other functional GI disorders, some of which share a number of risk factors for IBS. Unnecessary abdominal surgery is performed in a high proportion of IBS sufferers. Along with the established role for psychosocial conditions in IBS, other risk factors are emerging. Evidence for postinfectious IBS is mounting, but the clinical usefulness of characterizing such patients remains unclear. Food sensitivities are frequently present in IBS, but more well-conducted trials of avoidance diets and desensitization are needed. Finally,genetic markers in IBS are an increasing focus of attention, but the amount of phenotypic variance explained by genetic variability remains to be established.

Psychiatric and psychological dysfunction in irritable bowel syndrome and the role of psychological treatments

Psychosocial variables play a substantial role in the IBS condition of many patients. Evaluating and addressing adverse psychosocial factors is important to achieve satisfactory clinical outcomes with those patients. This can be achieved efficiently through psychosocial interviewing, establishing a solid therapeutic relationship, and judicious and tactful application of psychotropic medications and psychological treatments. Success in address-ing psychosocial factors in clinical encounters benefits not only patients, but also the gastroenterologist through increased work satisfaction because of reduced difficulty and frustration in working with IBS patients.

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

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

Irritable bowel syndrome in France: a common, debilitating and costly disorder

OBJECTIVE

This epidemiological investigation aims to measure the prevalence of irritable bowel syndrome (IBS) in the general population using the Rome II criteria and to evaluate the medical management including treatments and the impact of IBS on patient life.

METHODS

A nationally representative sample of 20,000 French subjects, aged 18 years and over, were interviewed by SOFRES (French Public Opinion Poll Institute) in May 2001. In a second phase (June/July 2001), a 48-question self-administered questionnaire was given to the subjects who have been selected during the first phase as suffering from IBS (Rome II criteria).

RESULTS

The prevalence of IBS was 4.7% (confidence interval, 4.36-5.04% with 5% risk) with a predominance in women (5.7% versus 3.7%, P < 0.01). The abdominal pain was often longstanding (> 5 years, 50%), intense (43%) and nocturnal (35%). During the most recent painful episode the levels of associated transit problems were almost equally divided between diarrhoea (36%), constipation (29%) and alternate episodes of both (31%). Apart from pain, bloating was given as the most frequent (73%) and most troublesome (24%) symptom. Since the onset, 80% of subjects with IBS had consulted a doctor (90% consulted a general physician, 57% a gastroenterologist, 50% both) and of these, 80% consulted within the previous 12 months. Sixty-seven per cent of subjects underwent additional investigations since the start of their illness (average of 3.4 examinations per patient examined: colonoscopy, 34.1%; laboratory tests, 34%; and abdominal ultrasound, 27.7%). Over the previous 12 months, 8% of the subjects had been admitted to hospital (average length of stay, 6.6 days), 11% of employed subjects had to take time off, 93% of subjects had taken prescribed medication (87%), but 43% of people thought it was ineffective. The effect on daily life was considerable (score, 6.2/10; close to the score for flu, 7/10). Two-thirds of the individuals changed their diet; 54% said it affected their social life and 29% their professional life. Seventy-four per cent of patients trusted their doctor, with a satisfaction index of 63%, but 45% of patients would like to have more information on IBS.

CONCLUSION

This study confirmed that the Rome II criteria detected IBS with a prevalence of 4.7%. The recruited subjects had severe symptoms (frequency, intensity and duration) that had a considerable effect on their daily life. The high level of referrals and initial consultations in all categories and the patient's attitudes towards the illness and its treatment emphasize the relative ineffectiveness of care for patients suffering from IBS.

Autonomic cardiovascular responses are impaired in women with irritable bowel syndrome

GOALS

This study characterizes cardiovascular autonomic function in women with irritable bowel syndrome (IBS), using standardized techniques.

BACKGROUND

Autonomic dysfunction is believed to contribute to abnormal gastrointestinal motility and visceral hypersensitivity in IBS. There is mounting evidence of generalized impairment of autonomic activity in patients with IBS.

STUDY

Thirty women aged 39 years (95% C.I. 25-53 years) diagnosed with IBS, and 30 age-matched healthy women were studied. The ratio of low frequency to high frequency heart rate variability domains (LF:HF ratio) was used to represent cardiac sympathovagal activity, and orthostatic testing and sustained isometric handgrip exercise were used as sympathetic stimuli. Parasympathetic activity was represented by the expiratory to inspiratory R-R interval (E:I) ratio during deep breathing at 6 minutes.

RESULTS

LF:HF responses to handgrip exercise (316%, C.I. 134% to 498% vs. 107%, C.I. 15% to 153%; P < 0.05) and orthostatic testing (648%, C.I. 520% to 904% vs. 330%, C.I. 140% to 520%; P < 0.05) were higher in IBS patients than controls, and the E:I ratio was significantly lower (1.47, C.I. 1.33-1.61 vs. 1.20, C.I. 1.14-1.26; P < 0.01).

CONCLUSIONS

Autonomic cardiovascular function is impaired in IBS, manifest as attenuated cardio-vagal tone, and relative sympathetic excess during stimulated conditions.

Central nervous system involvement in functional gastrointestinal disorders

Although functional gastrointestinal disorders (FGID) are common, their pathophysiology remains incompletely understood. It is generally accepted that dysfunction of the bidirectional pathways between the gastrointestinal tract and the central nervous system (the 'brain-gut axis') at any level can cause FGID symptoms. In this review article, we focus on the role of the central nervous system in the brain-gut axis. First, we describe the functional anatomy of the brain-gut axis. Second, we focus on the results from brain-imaging studies both in healthy volunteers and in FGID patients. These new investigational techniques made identification of brain regions critically involved in processing of visceral afferent information possible. Differences in central nervous system response to visceral stimuli between controls and FGID patients will be highlighted. Third, we will address the issue of high comorbidity with psychiatric disorders. Some hypotheses about common pathophysiological substrates will be discussed.

[Irritable bowel syndrome]

The prevalence of irritable bowel syndrome (IBS) ranges in all countries of the world between 6 and 25%, in Germany between 15 and 22%. The divergent rates of prevalence are mainly due to different definitions of IBS in epidemiological studies. In Germany, 20-50% of persons with IBS symptoms seek medical help. IBS patients produce high direct and indirect costs. The following psychophysiological mechanisms of IBS are presumed to be empirically validated: visceral hypersensitivity, postinfectious sequelae, psychiatric disorders, and psychosocial stress. Tricyclic antidepressant agents and psychotherapy (hypnosis, cognitive behavioral therapy, and psychodynamic therapy) are effective for treatment of IBS forms dominated by pain. In one controlled study, the combination of pharmacological therapy and cognitive behavioral therapy was superior to pharmacological therapy alone.

Management of irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders. The prevalence rate is 10-20% and women have a higher prevalence. IBS adversely affects quality of life and is associated with health care use and costs. IBS comprises a group of functional bowel disorders in which abdominal discomfort or pain is associated with defecation or a change in bowel habit, and with features of disordered defecation. The consensus definition and criteria for IBS have been formalized in the "Rome II criteria". Food, psychiatric disorders, and gastroenteritis are risk factors for developing IBS. The mechanism in IBS involves biopsychosocial disorders; psychosocial factors, altered motility, and heightened sensory function. Brain-gut interaction is the most important in understanding the pathophysiology of IBS. Effective management requires an effective physician-patient relationship. Dietary treatment, lifestyle therapy, behavioral therapy, and pharmacologic therapy play a major role in treating IBS. Calcium polycarbophil can benefit IBS patients with constipation or alternating diarrhea and constipation.

Relationship between abdominal pain subgroups in the community and psychiatric diagnosis and personality. A birth cohort study

INTRODUCTION

It is unclear if there is a causal link between psychiatric disorders and unexplained chronic gastrointestinal (GI) symptomatology. The role of personality is also in dispute. We aimed to assess the association of these factors with functional GI symptoms in a birth cohort study.

METHODS

The Dunedin birth cohort is well characterised and has been followed-up prospectively to age 26 (n=980). Measured were upper and lower GI symptoms over the prior year at age 26 using a validated questionnaire, psychiatric diagnoses at ages 18 and 21 by standardised interview applying DSM-III-R criteria, and personality at age 18 using the Multidimensional Personality Questionnaire (MPQ). Natural symptom groupings were identified using factor analysis and k-means clustering. The association of these clusters and psychiatric diagnoses or personality was assessed by logistic regression.

RESULTS

The k-means analysis produced a six-cluster solution, which was made up of a health group, and five "disease" clusters defined by higher than average scores on a single symptom. A diagnosis of depression at age 18 or 21 years was associated with increases in the odds of 1.69 (95% CI: 1.27-2.25) for all GI, of 2.16 (95% CI: 1.12-4.16) for dysmotility and of 2.07 (95% CI: 1.13-3.80) for constipation, but not with the other clusters. Similar results were observed with respect to anxiety disorders for the odds of GI overall (OR=1.42, 95% CI: 1.01-1.99) and constipation (OR=2.11, 95% CI: 1.17-3.79). The personality subscales were not strongly linked; membership of "any" diseased cluster was associated with a reduced odds of being in the fourth quartile for the well-being scale (OR=0.64, 95% CI: 0.46-0.88) but increased odds of being in the fourth quartile for the social potency scale (OR=1.64, 95% CI: 1.18-2.28).

CONCLUSIONS

In a young adult community sample, unexplained GI symptoms appear to be linked to psychiatric disorders but personality differences were minimal.

Time cluster and symptom character of 402 outpatients with irritable bowel syndrome

AIM

To understand the time cluster regularity of the patients first caught by irritable bowel syndrome(IBS), and provide clue for further research on etiologic agents.

METHODS

According to diagnostic criteria of Rome II, 402 cases of IBS were investigated by questionnaire, and the onset month was analyzed with circular distribution.

RESULTS

The longest course of IBS was 54 years, and the average course was 7.62 years. There was no difference between males and females in course distribution (χ² = 2.35, P>0.05). IBS is a seasonal disease with high occurrences in spring (Z = 31.78, P<0.01). Males had high occurrences in March (Z = 18.37, P<0.01), however females in April (Z = 16.55, P<0.01). There was a significant difference between male and female in the onset month. In IBS patients, diarrhea predominance accounted for 36.6%, and constipation predominance 18.4%, and others 45.0%. There was a significant difference in predominance between males and females (χ² = 7.77, P<0.05). Abdominal pain was the most common symptom.

CONCLUSION

IBS has seasonal occurrence, so season is probably one of the influential factors of IBS.

Irritable bowel syndrome: a little understood organic bowel disease?

Irritable bowel syndrome affects 10% of adults with an unexplained female predominance. Although only a few people see their family doctor, the disease causes reduced quality of life and represents a multi-billion pound health-care problem. The disorder clusters in families, which is possibly because of intra-familial learning and a genetic predisposition. Visceral hypersensitivity is a key feature in most patients. Results of imaging studies of regional cerebral blood flow during rectal distension suggest underlying disturbances of central processing of afferent signals, though this is not unique to the disorder, since it is seen in other chronic pain syndromes. Environmental factors that are strongly implicated in at least some patients include gastrointestinal infection and inflammation and chronic stress. Diagnosis is based on positive symptoms and absence of any alarm indicators. Treatment remains unsatisfactory and hinges on an excellent doctor-patient relationship, with drugs for symptom exacerbations. Cognitive behavioural treatment, psychotherapy, and hypnosis could provide long-lasting benefit in some patients. Tricyclic antidepressants in low doses seem to be the most effective class of drugs for the disorder on the basis of limited data.