Irritable bowel syndrome in the elderly

Best Practice & Research Clinical Gastroenterology Vol. 16, No. 1, pp. 63±76, 2002

doi:10.1053/bega.2002.0266, available online at http://www.idealibrary.com on

5 Irritable bowel syndrome in the elderly Greg Bennett

MBBS, FRACP

Nicholas J. Talley*

MD, PhD, FRACP

Professor Department of Medicine, University of Sydney, Nepean Hospital, PO Box 63, Penrith, NSW 2751, Australia

Irritable bowel syndrome (IBS) is a highly prevalent and frequently lifelong gastrointestinal disorder, but whether advancing age impacts on IBS is largely unknown and how the disorder manifests in the elderly remains unclear. Epidemiological studies suggest that the prevalence of IBS declines with age (possibly related to pain perception changes), but IBS remains a common gastrointestinal illness in the aged. Unfortunately, there has been very little research examining risk factors, diagnosis and treatment of IBS in the elderly. Since gastrointestinal cancer increases with age, diagnostic algorithms di€er in the elderly. There is reason to believe that this very prevalent disorder may also behave di€erently in the elderly and that the approach to management needs to take age-related issues into account. These issues will be the focus of the present review. Key words: abdominal pain, epidemiology; accidental falls; age factors; aged, 80 and over; colonic diseases, functional, epidemiology; confusion; constipation, epidemiology; diarrhoea, epidemiology; drug therapy, epidemiology; faecal incontinence; female; frail elderly; gastroenteritis; human; male; natural history; nutrition; patient acceptance of health care; prognosis, epidemiology; questionnaires; risk factors; sex factors.

INTRODUCTION Advancing age is associated with an increasing prevalence of many chronic disabling neurological and cardiovascular diseases; furthermore, polypharmacy, undernutrition, sarcopaenia and physical and mental disability are prevalent issues in the elderly that can impact on management.1±7 It is, therefore, no surprise that the elderly are the greatest consumers of health care. It is now well documented that the presentation of many diseases is frequently altered in the aged,8 but the clinical presentation of functional gastrointestinal disorders in various subpopulations of the elderly remains largely undocumented. Occam's razor dictates that a single cause be sought to explain a set of symptoms, but modern geriatric medicine has learned that seeking multiple causes best explains the geriatric syndromes (including falls, gait disorders, confusion, incontinence, *All correspondence to: Professor Nicholas J. Talley. Tel: ‡61 (0)2 4734 2613; Fax: ‡61 (0)2 4734 2614; E-mail: [email protected] 1521±6918/01/160063‡14 $35.00/00

c 2002 Harcourt Publishers Ltd. *

64 G. Bennett and N. J. Talley

or failure to thrive/weight loss.9 Multiple co-morbidities in the elderly are likely to impact on the management of functional bowel disease. DEFINITIONS Functional gastrointestinal disorders are characterized by chronic or recurrent gastrointestinal symptoms that cannot be explained by structural or metabolic abnormalities. There are numerous criteria in the literature that have been applied to de®ne irritable bowel syndrome (IBS). The Manning criteria have been variably de®ned, but typically have included abdominal pain plus two (or three) of six speci®c symptoms (namely, abdominal pain relieved by defaecation, looser stools or more frequent stools at pain onset, abdominal distension, mucus per rectum, or feelings of incomplete rectal evacuation).10 Following international consensus (the Rome II criteria), IBS is currently de®ned as 12 weeks or more in the prior year of abdominal discomfort or pain associated with two or more of the following: relieved by defaecation or associated with a change in stool frequency or stool form (hard or loose).11 Other symptoms, such as altered stool passage (straining or urgency, feeling of incomplete evacuation), passage of mucus and bloating or feeling of abdominal distension, support the diagnosis. Chronic functional constipation is distinguished from IBS, being characterized by a more constant disturbance of defaecation; straining or hard stools predominate with less prominent pain.11 The value of the di€erent published de®nitions for identifying IBS is currently a matter of major research interest. Five commonly used research de®nitions for the identi®cation of IBS were recently compared in Glostrup, Denmark, in a populationbased cohort study.12 The study included 4122 people aged 70 years. The Manning and Rome I criteria were reasonably concordant (k ˆ 0.72), but most other measures were associated with fewer than 50% of subjects in common. Therefore, wide variation in study populations selected by di€erent de®nitions may make generalizability of the results uncertain, although how much age actually a€ects these de®nitions is unclear. EPIDEMIOLOGY Regardless of the de®nition used, IBS is an extremely common disorder accounting for more new referrals to gastroenterologists than any other disorder.13±15 The majority of patients with IBS present in the third to fourth decade of life.11,16,17 At all ages, the disease has a female preponderance. Presentation after the age of 60 has been considered to be less common. There are few studies that have included the elderly and even fewer that have speci®cally focused upon the elderly.18 The latter are discussed individually below. Prevalence The Glostrup population studies in Denmark reported prevalence, incidence and prognosis of gastrointestinal symptoms in 1119 70-year-old Danish subjects who were randomly selected from the population and followed up over 5 years.19 The prevalence of IBS was measured using ®ve di€erent methods. The prevalence varied from 6±18% depending on the de®nition, although the incidence rates over the 5-year follow-up period were of a similar magnitude. At the 5-year follow-up point, 50±79% of subjects who originally had su€ered from IBS no longer did so.

Irritable bowel syndrome in the elderly 65

48

(A)

42 36 %

30 24 18 12 6 0 65–74

75–84

>85

Age (years) 48 42

(B)

36 %

30 24 18 12 6 0 65–74

75–84

>85

Age (years) Figure 1. Prevalence of symptoms in Olmsted County, MN, USA in subjects aged 65±93 years (n ˆ 328). Irritable bowel syndrome (IBS) was de®ned by the Manning criteria (pain plus 42 out of 6 symptoms). (A) Males. (B) Females. s, constipation; n, diarrhoea; h, faecal incontinence; e frequent pain; d IBS. Reproduced, with permission, from Talley et al.26

A population-based study in Olmsted County, MN, USA surveyed 328 respondents aged between 65 and 93 years (Figure 1). IBS, as estimated by the Manning criteria, was 10.9/100 (95% con®dence interval (CI) ˆ 7.2±14.6).20 Chronic constipation and chronic diarrhoea had prevalence rates of 24.3 (95% CI ˆ 19.3±29.2) and 24.1 (95% CI ˆ 19.1±29.0), respectively. A parallel study of people aged 30±64 years suggested that the prevalence of IBS was somewhat less in the older population.10 Ruigomez and colleagues reported ®ndings from a 12-month follow-up of a population-based cohort incidence study (the UK General Practice Research Database) of nearly 600 000 patients aged between 20 and 79 years.21,22 Pregnant patients and those su€ering from cancer or other gastrointestinal diseases were excluded. The newly diagnosed cohort of IBS su€erers comprised 2956 subjects, most of whom were young or middle aged. Only 12% of IBS occurred in people 60 years or older, who represented just 22% of the study population; 74% were women. The data suggest that the prevalence of new onset IBS in the elderly is less than half that of people under the age of 60 years. There were no marked di€erences in the use of health care services or co-morbidity

66 G. Bennett and N. J. Talley

status before or after the diagnosis IBS was made. Furthermore, 14% of patients received no drug treatment. Among those treated, anti-spasmodics were the most common drugs used. Notably, the elderly were more likely to receive drug treatment. Post-gastroenteritis IBS Approximately one in ®ve IBS su€erers report an antecedent history consistent with acute gastroenteritis and new data suggest that while this can also occur in the elderly, the risk is less. Neal et al23 prospectively studied the development of IBS following microbiologically con®rmed bacterial gastroenteritis in 544 people from the Nottingham Health Authority in the UK. Gastrointestinal symptoms were recorded for the 6 months after and, retrospectively, in the 6 months prior to the gastroenteritis episode. IBS was diagnosed according to modi®ed Rome criteria, by two experienced clinician-observers, separately. There was high inter-observer agreement, and the response rate was 72%. About one in four subjects reported persistence of altered bowel habit and one in 14 developed IBS. The adjusted relative risk (RR) of persistent bowel symptoms was 0.36 (95% CI ˆ 0.1±0.9) for over 60 year olds, indicating about one-third the risk of that of 19±29 year olds. Subjects between the ages of 40 and 59 had half the risk of over 60 year olds, while females had three times the risk of men. Those with prolonged acute episodes lasting more than 2 weeks had six times the likelihood of developing persistent bowel symptoms. This study suggests that younger people and female gender are associated with a higher risk of IBS development. Gwee et al24 prospectively explored psychometric issues and the persistence of IBS symptoms after infectious diarrhoea in a group of consecutive admissions to hospital with acute gastroenteritis; subjects were aged 18±80 years. Patients who developed IBS had signi®cantly higher scores for anxiety, depression, somatization and neurotic traits than did those who returned to normal bowel function, but unfortunately the study did not analyse the data by age.24 Consulters versus non-consulters In the USA and UK, approximately one-third of IBS su€erers ever attend a physician for their symptoms.10 Although published data speci®cally concerning the elderly are absent, it is likely that many older patients with IBS symptoms never seek help.22,25 Indeed, symptoms appear to be a poor predictor of presentation to medical care.26 Symptoms that are more likely to be associated with presentation include faecal soiling in the minority who su€er it. A recent study of 657 IBS su€erers compared specialty clinic patients (52%) with those responding to an advertisement for clinical trials (48%); the clinic population reported more prevalent and severe abdominal pain and scored higher on psychological symptom scores, while the advertisement population had a better quality of life and similar visceral perception scores,27 but again age was not speci®cally analysed in the data. Consulters are more likely to see physicians for nongastrointestinal symptoms, suggesting the presence of psychological factors,28 a plausible explanation supported by other studies.29 NATURAL HISTORY AND PROGNOSIS While long-term studies are few, it appears that among all ages IBS has a good prognosis.6,30 The 5-year follow-up study from Glostrup, Denmark con®rmed this speci®cally in community-dwelling elderly subjects aged 70 years, with 50±79% of

Irritable bowel syndrome in the elderly 67

su€erers no longer having the disorder at follow-up.19 Psychological factors may impact on the natural history of IBS, but these have not been speci®cally assessed in the aged. In a younger cohort of consecutive outpatients, the perceived threat of chronic life stress was a powerful predictor of subsequent symptom intensity in a 16-month followup study.31 All patients who improved did so in the absence of such a stressor.31 Another long-term follow-up study in outpatients suggests that a good prognosis may be related to the strength of the initial physician±patient interaction.6 CLINICAL FEATURES General issues in the aged The elderly have an increasing propensity for altered pain perception and pain localization.32±34 Therefore, the way diseases manifest symptomatically may be altered. For example, acute myocardial infarction, acute urinary cystitis or acute urinary retention may manifest as delirium or falls with symptoms poorly localized to the relevant organ system.8,9 There is some evidence to support the hypothesis that a reduction of IBS prevalence in the elderly is associated with reduced pain perception with age. Laginer et al5 measured rectal sensory thresholds in 12 healthy elderly subjects (mean age 86 years) and compared the results with young adults (mean age 26 years). Compliance was not di€erent, but distension sensory thresholds were signi®cantly increased in the elderly.5 These results need to be con®rmed in elderly subjects with and without IBS. It is also important to keep in mind that the elderly have a higher prevalence of other diseases, such as chronic mesenteric ischaemia or colon cancer, which may mimic intermittent IBS symptoms and may considerably alter diagnostic considerations. Furthermore, the health and physiological status of the elderly population is highly heterogeneous. It is useful to think of elderly populations in terms of the `young old' and `old old'. The young old tend to behave more like the normal adult population for many diseases. For example, age was not associated with altered upper gut function in younger or older patients with unexplained gastrointestinal symptoms, but subjects were all under the age of 70 years.35 It is also useful to subdivide the very elderly into the well old and the frail old. Most gastrointestinal functions are unchanged in the elderly, but the gut's performance in the frail and disabled aged can be signi®cantly disturbed after minor insults because there is reduced intestinal reserve.36±38 Over the age of 75 years, the prevalence of many degenerative diseases tends to dramatically increase; for example, stroke and Parkinsonism can signi®cantly alter gut function causing defaecatory disturbances.2,3,7,38 Most gastrointestinal functions are unchanged in the well elderly. Only a few studies of colonic function have been reported in the healthy aged. Overall, it appears that colonic transit and motility are unchanged compared with younger subjects.36,37,39 However, the gut's performance in the frail and disabled may be signi®cantly disturbed. Several studies have demonstrated delayed transit time in the elderly.10,36,37,40±44 Studies of functional gastrointestinal syndromes have not explored these physiologically diverse groups. Similarly how IBS symptomatology may be altered in di€erent subpopulations of the elderly is unexplored. Gastrointestinal symptoms IBS is a condition marked by waxing and waning symptoms, with exacerbations, which may occur in relation to stress,45 menstruation,46 sleep disturbance47 or eating.20 Very

68 G. Bennett and N. J. Talley

little research has been undertaken on people over the age of 65 years or in comparing old with young su€erers. One non-population based study of di€erent groups of IBS su€erers included 100 older people from aged persons apartments;48 this study suggested that the elderly have typical IBS symptoms with a predominance of constipation features. The exact pathophysiology remains obscure, but a disorder of inhibitory control of neuromuscular function that results in colonic segmentation and dis-co-ordination could lead to both IBS and colonic diverticulosis.18 Abdominal pain Abdominal pain in IBS is poorly localized, but is frequently reported in the mid to low abdomen. The character of the pain is variable, but is most commonly described as being cramp-like or aching. Pain typically occurs in bouts and classically is relieved by defaecation or by the passage of ¯atus. The pain may also be associated with an increased or decreased frequency of defaecation, or with looser or harder stools at the onset of the pain. Disturbed defaecation Disturbances in defaecation are typically intermittent, with some normal bowel habit intervening. Disturbances include constipation, diarrhoea, or alternating constipation and diarrhoea. However, such terms are often used very loosely by patients. Constipation may be reported as decreased bowel frequency, passage of inspissated faeces, straining during defaecation, or an inability to achieve complete evacuation. With increasing age, there is an increased frequency of perineal descent among older women, which may be associated with a sense of incomplete evacuation.49 In older men, chronic prostatic disease may be a cause of intermittent loose stools, passage of mucus, low abdominal pain, or a sense of incomplete evacuation.50 The prevalence of urinary and faecal incontinence is increased in the elderly, although some patients may report faecal incontinence as diarrhoea unless speci®cally asked. The prevalence of faecal incontinence in a mail survey in the elderly in Olmsted County, MN, USA, occurring more than once per week was reported to be 3.7% (95% CI ˆ 7.2±14.6). In another survey, 14% of IBS su€erers reported rectal urgency51 and this symptom may be slightly more common in elderly IBS su€erers.10,26 Other gut symptoms IBS su€erers also report other gastrointestinal symptoms including abdominal distension, borborygmi, passage of mucus in the stool and excessive ¯atus. Nausea, vomiting, dysphagia, gastro-oesophageal re¯ux and early satiety have all been reported more often by patients with IBS than by controls, when matched for age, gender and social class.52 In adults, IBS has been associated with a twofold increased frequency of bronchial hypersensitivity, after controlling for symptoms of gastro-oesophageal re¯ux disease.53 Bladder symptoms In a recent study of a representative population cohort, IBS symptoms were positively associated with increased urinary urgency, nocturia, frequency of micturition and bladder instability as measured by urodynamics.54,55 The e€ect of age on these extraintestinal complaints in IBS has not been de®ned.

Irritable bowel syndrome in the elderly 69

Functional status Data from the Glostrup, Denmark population study of 1119 older people aged 70 years who were interviewed and visited in their homes by an occupational therapist provides new insights on the impact of IBS in the elderly. Both IBS and dyspepsia were more common among subjects with reduced functional ability. At the 5-year followup, IBS was associated with deterioration in functional ability.56 Assessments were made by an occupational therapist using validated measures of functional status in the elderly. Items included measures of personal care and the ability to perform instrumental activities of daily living such as the ability to shop. From the data presented it is dicult to determine whether the deterioration was clinically or practically important. Functional status overall was good in the group of 70 year olds. The associated decline in function in IBS su€erers may become more important with increasing age or over a longer follow-up period and, therefore, the nature of the association warrants further investigation. DIFFERENTIAL DIAGNOSIS The di€erential diagnosis of colonic symptoms in the elderly is similar to that in the younger population, but the increased prevalence of organic diseases means exclusion of organic disease is relatively more important. In the elderly, there is an increased prevalence of colonic and other cancers, mesenteric ischaemia, thyroid disorders, diabetes, depression, medication-induced constipation, autonomic neuropathy and small bowel bacterial overgrowth. There are numerous symptoms suggesting possible organic disease (Table 1). Of note, 90% of colorectal cancers occur in people over 50 years of age, while over 80 year olds account for 23±40% of all colorectal cancers.57 One therefore should maintain a low threshold for colonoscopic investigation. In the elderly, multiple diseases and medications commonly co-exist to cloud the diagnosis. A low threshold is therefore warranted to investigate further. Small bowel bacterial overgrowth in the

Table 1. List of symptoms that suggest possible organic disease. Age at onset 4 50 years Unintentional weight loss Symptoms are of recent onset Symptoms are steadily progressive Severe or unremitting pain Pain or diarrhoea waking the patient up at night Vomiting, fever, rectal bleeding Laboratory abnormalities: Anaemia Leukocytosis Elevated erythrocyte sedimentation rate or CRP Electrolyte abnormalities Elevated liver enzymes Elevated TSH Positive stool occult blood test

70 G. Bennett and N. J. Talley

elderly may occur without an anatomical abnormality; this overgrowth is associated with weight loss and vague gastrointestinal symptoms including bloating and diarrhoea.58 Gastric hypochlorhydria and proton pump inhibitor use have been associated with small bowel bacterial overgrowth.59,60 TREATMENT ISSUES No clinical trials speci®cally involving elderly patients were identi®ed in a search of Embase and Medline databases. The average age of participants in all IBS studies is less than 49 years and subgroup analysis of older populations has not been performed. At this time, otherwise healthy older patients should be approached in the same way as younger patients; the frail old present a greater challenge. A comprehensive discussion of treatment is beyond the scope of this chapter, but speci®c issues in the elderly will be highlighted. A general approach A recent, well designed, systematic review of randomized controlled trials of therapeutic agents by Jailwala et al61 came to the following conclusions: smooth muscle relaxants appeared to be ecacious when pain was the predominant symptom, but the ecacy of bulking agents was unclear. Loperamide was e€ective for diarrhoea but not for pain. Evidence for the use of tricyclic anti-depressants was supported by a separate, recent, meta-analysis.62 In the absence of speci®c data, it is reasonable to assume that older IBS su€erers will be similar to younger su€erers in their response to treatment. In the frail aged and those of great age, all treatment strategies may have increased adverse e€ects. Despite these data, the treatment of IBS remains largely empirical and symptomatic (Table 2). Management must be individualized. Reassurance with explanation plus sensible dietary modi®cations and exercise recommendations remain the mainstay of treatment. Fibre intake is low in many older people and improving ®bre intake with adequate hydration may help some su€erers with constipation (although bloating may be aggravated). While ®bre may ®rm up the stools in persons with diarrhoea, this is not of proven bene®t. Fibre should be introduced in small amounts and only increased slowly, to minimize intolerance. Table 2. Treatment approaches for IBS in the elderly. A. General principles Reassurance and explanation Explanation about precipitating factors Exploration and explanation about psychological factors Dietary and hydration advice Follow-up to assess understanding of general principles and to reinforce general principles B. Drug therapy: consider risk of drug non-compliance and adverse e€ects, e.g. confusion, falls, blurred vision For constipation: bulking agent, lactulose, polyethylene glycol±electrolyte solutions For diarrhoea: loperamide, aluminium hydroxide, cholestyramine C. Refractory or severe symptoms Anti-depressants

Irritable bowel syndrome in the elderly 71

Dehydration is common in many patients and may exacerbate symptoms in those with constipation-predominant IBS. Reduced thirst sensation has been documented in older people and predisposes then to dehydration, especially in hot weather. It is worth inquiring about urinary incontinence or urgency of micturition, since many patients with this problem inappropriately restrict ¯uid intake to minimize their symptoms. Inadequate water intake associated with ®bre or bulking agent supplementation may exacerbate dehydration and result in hardened stools.63 Choose drugs matched to the patient's risk of adverse e€ects According to a large cohort study in the UK,21 older people with IBS are more likely to be treated with drug therapy, although the reason for this was not determined. Adverse drug e€ects are common causes of morbidity and hospitalization in the elderly.64 The main adverse e€ects of drugs in the elderly are falls, confusion, urinary retention, constipation and cardiac arrhythmias. Loperamide is generally safe in older people, provided faecal impaction with over¯ow diarrhoea has been excluded. Central nervous system depression may occur with loperamide, so that confusion and falls are potential adverse e€ects. Care needs to be taken using magnesium-containing compounds for constipation in frail older people with even a modest elevation of serum creatinine, because of the risk of neuromuscular suppression from magnesium toxicity.65 Anti-spasmodic drugs such as mebeverine and anti-cholinergics may sometimes be useful in abdominal pain, but must be used with caution to avoid adverse drug e€ects in the elderly. Many anti-spasmodics and anti-depressants possess anti-cholinergic activity. Important potential adverse e€ects include cardiac arrhythmias, confusion, urinary retention, dry mouth and blurred vision. Confusion Normal ageing of the brain is associated with an appreciable reduction in cholinergic activity. Signi®cant degrees of memory loss commonly go unrecognized. Alzheimer's disease, the most prevalent dementia, is characterized by speci®c and severe reductions in cholinergic activity in the amygdala and nucleus basalis and their projections.66 The prevalence of dementia is approximately 5% in 75 year olds and then doubles every 5 years; 35% of 90 year olds can be expected to have Alzheimer's disease. The use of anticholinergic drugs in this context is likely to cause reversible cognitive deterioration and delirium, sometimes with important disturbances of behaviour. Patients who present with a vague history and possible memory loss should always be assessed for cognitive impairment; several brief tools are available such as the short mental status questionnaire or the modi®ed Folstein mental status test. Falls The prevalence of postural instability and disorders of gait range from 8±19% in noninstitutionalized elderly patients.25,67 Drugs are often implicated as causing falls, especially in individuals at risk because of gait and balance problems. Psychotropic drugs have been associated with an increased risk of falls of up to 28-fold.68 A cohort study by Thapa et al,69 controlling for the e€ect of depression and psychological disorders, found a threefold risk of falling in persons taking tricyclic anti-depressants. Previous `fallers' are particularly at risk.69 The clinician should obtain a history regarding dizziness, falls and

72 G. Bennett and N. J. Talley

gait problems before prescribing psychoactive drugs, even if the prescribed dose is low. Physical therapy is useful in improving gait and balance in many patients.70 Home assessment and modi®cations may also reduce the risk of falls.71 Patients with gait and balance disorders should be referred to a falls, gait and balance unit. Cardiac arrhythmias Patients with cardiac disease warrant care with the prescription of commonly used antispasmodics such as mebeverine and dicyclomine, or tricyclic anti-depressants. Ischaemic heart disease is commonly silent in this age group. The initial commencement dose should be lower than the usual maintenance dose. An electrocardiogram (ECG) is appropriate for excluding partial or complete atrioventricular block before using mebeverine in frail aged patients at risk of cardiac disease. Medication compliance This is an important issue in older people, especially those taking multiple drugs.72,73 Patients with cognitive impairment are likely to be at great risk for not complying with medication regimes. The use of written instructions, bearing in mind the visual and mental status of the patient, can be helpful. Methods that improve compliance in practice include a carer dispensing medication or the use of blister packs. Nutritional issues Community dwelling older people su€er a high prevalence of undernutrition, ranging from 30±60% depending on the de®nition applied.74 Undernutrition probably has an independent impact on outcomes, including mortality, in the elderly. Older people su€ering from IBS may associate food intake with symptoms and, subsequently, reduce their food intake to avoid pain. It is therefore appropriate to obtain a dietary history and to enquire about perceptions of food intake and symptoms. Nutrition should be attended to as part of the management plan.

CONCLUSIONS There are hints that IBS in older persons di€ers signi®cantly from the condition in younger persons, but surprisingly little data are available. IBS is likely to be an underrecognized condition in the elderly. Much remains to be learned about IBS in old age. Although the condition in the elderly may be somewhat less prevalent than in younger people, IBS is likely to have a signi®cant impact both economically as well as in terms of impaired quality of life in older su€erers. While studies in the elderly remain potentially challenging, especially in terms of invasive investigations, new non-invasive techniques for assessing motor and sensory function should overcome some of the methodological limitations.18 Indeed, studies in the elderly may provide novel insights into the pathophysiology and management that can be applied to all age groups a‚icted. As the proportion of elderly people continues to increase exponentially, it seems timely for more work to be devoted to this ®eld.

Irritable bowel syndrome in the elderly 73

Practice points . very few studies have focused speci®cally upon the elderly . irritable bowel syndrome (IBS) is a common disorder in the elderly, but may be less common than in middle-aged persons . a low threshold is warranted to further investigate gut symptoms in older patients . in the elderly, organic diseases are more prevalent. Multiple diseases and medications commonly co-exist to cloud the diagnosis . in the elderly, the presence of IBS has been associated with functional decline over time . evidence pertaining to the ecacy of medications used in the elderly in clinical trials is lacking . some drug treatments for IBS (e.g. anti-cholinergics, tricyclic anti-depressants) may exacerbate or cause confusion, falls or cardiac arrhythmias in the elderly

Research agenda . diagnostic criteria need to be explored and validated in all `subgroups' of older people (e.g. well old and frail old) . the relationship between IBS and functional status, brain and neuromuscular function, physical activity and other disorders needs exploration . non-functional gastrointestinal disorders are more common in the elderly. Therefore diagnostic approaches for IBS warrant speci®c evaluation . clinical therapeutic trials should be undertaken in older populations speci®cally to ascertain treatment ecacy and tolerance

REFERENCES 1. Australian Bureau of Statistics. Older People, Australia: A Social Report. ABS Cat No. 4109.0. Australian Bureau of Statistics, 1999. 2. Akhtar AJ, Broe GA, Crombie A et al. Disability and dependence in the elderly at home. Age and Ageing 1973; 2: 102±111. 3. Broe GA, Akhtar AJ, Andrews GR et al. Neurological disorders in the elderly at home. Journal of Neurology, Neurosurgery and Psychiatry 1976; 39: 361±366. 4. Jette AM & Branch LG. The Framingham disability study: II Physical ability among the ageing. American Journal of Public Health 1981; 71: 211±216. 5. Laginer E, Delvaux M, Vellas B et al. In¯uence of age on rectal tone and sensitivity to distension in healthy subjects. Neurogastroenterology and Motility 1999; 11: 101±107. 6. Owens DM, Nelson DK & Talley NJ. The irritable bowel syndrome: long-term prognosis and the physician±patient interaction. Annals of Internal Medicine 1995; 122: 107±112. 7. Waite LM, Broe GA, Creasey H et al. Neurodegenerative and other chronic disorders among people aged 75 years and over in the community. Medical Journal of Australia 1997; 167: 429±432. 8. Horan MA. Presentation of disease in old age. In Brockelhurst, Tallis & Fillit (eds) Geriatric Medicine and Gerontology, 4th edn, pp 145±149. London: Churchill Livingstone, 1992. 9. Cape RDT. Aging: Its Complex Management. Hagerstown: Harper and Rowe, 1978. 10. Talley NJ, Zinsmeister AR, Van Dyke C & Melton LJ III. Epidemiology of colonic symptoms and the irritable bowel syndrome. Gastroenterology 1991; 101: 927±934. 11. Drossman DA, Coruzziari IE, Talley NJ, Thompson WG & Whitehead RWE (eds). Rome II Functional Gastrointestinal Disorders, 2nd edn. McLean, VA: Degnon Associates, 2000.

74 G. Bennett and N. J. Talley 12. Kay I, Jorgensen T & Lanng C. Irritable bowel: which de®nitions are consistent? Journal of Internal Medicine 1998; 244: 489±494. 13. Ferguson A, Sircus W & Eastwood MA. Frequency of `functional' gastrointestinal disorders. Lancet 1977; 2: 613±614. 14. Harvey RF, Salih SY & Read AE. Organic and functional disorders in 2000 gastroenterology outpatients. Lancet 1983; 1: 632±634. 15. Switz DM. What the gastroenterologist does all day: a survey of a state's society's practice. Gastroenterology 1976; 70: 1048±1050. 16. Havia T & Manner R. The irritable colon syndrome. Acta Chirurgica Scandinavica 1971; 137: 569±572. 17. Waller SL & Misiewics JJ. Prognosis in the irritable-bowel syndrome. Lancet 1969; 2: 753±756. 18. Camilleri M, Lee JS, Viramontes B et al. Insights into the pathophysiology and mechanisms of constipation, irritable bowel syndrome, and diverticulosis in older people. Journal of the American Geriatric Society 2000; 48: 1142±1150. 19. Kay L. Prevalence, incidence and prognosis of gastrointestinal symptoms in a random sample of an elderly population. Age and Ageing 1994; 23: 146±149. 20. Ragnarsson G & Bodemar G. Pain is temporally related to eating but not to defaecation in the irritable bowel syndrome. European Journal of Gastroenterology and Hepatology 1998; 10: 415±421. 21. Rodriguez LAG & Ruigomez A. Increased risk of irritable bowel syndrome after bacterial gastroenteritis: cohort study. British Medical Journal 1999; 318: 565±566. 22. Ruigomez A, Wallander MA, Joansson et al. One year follow-up of newly diagnosed irritable bowel syndrome patients. Alimentary Pharmacology and Therapeutics 1999; 13: 1097±102. 23. Neal KR, Hebden J & Spiller R. Prevalence of gastrointestinal symptoms six months after bacterial gastroenteritis and risk factors for the development of the irritable bowel syndrome: postal survey of patients. British Medical Journal 1997; 314: 779±782. 24. Gwee KA, Graham JC, McKendrick MW et al. Psychometric scores of irritable bowel after infectious diarrhoea. Lancet 1996; 347: 150±153. 25. Leon J & Lair T. Functional Status of the Non-Institutionalised Elderly: Estimates of ADL and IADL Diculties. National Medical Expenditure Survey Research Findings 4. DHSS Publication No. PHS 90±3462. Public Health Service. Rockville, MD: Agency for Health Care Policy and Research, 1990. 26. Talley NJ, O'Keefe EA, Zinsmeister AR & Melton LJ III. Prevalence of gastrointestinal symptoms in the elderly: a population-based study. Gastroenterology 1992; 102: 895±901. 27. Lee OY, Fitzgerald LZ, Nalibo€ B et al. Impact of advertisement and clinic populations in symptoms and perception of irritable bowel syndrome. Alimentary Pharmacology and Therapeutics 1999; 13: 1631±1638. 28. Sandler RS, Drossman DA, Nathan HP et al. Symptom complaints and health care seeking behaviour in subjects with bowel dysfunction. Gastroenterology 1984; 87: 314±318. 29. Whitehead WE, Bosmajian L, Zoderman AB et al. Symptoms of psychologic distress associated with irritable bowel syndrome: comparison of community and medical clinic samples. Gastroenterology 1988; 95: 709±714. 30. Harvey RF, Mauad EC & Brown AM. Prognosis in the irritable bowel syndrome: a ®ve year prospective study. Lancet 1987; 1: 963±965. 31. Bennett EJ, Tennant CC, Piesse C et al. Level of chronic life stress predicts clinical outcome in irritable bowel syndrome. Gut 1998; 43: 256±261. 32. Bender MB. Perceptual interaction. In William D (ed.) Modern Trends in Neurology. London: Butterworths, 1970. 33. Halar EN, Hammond MC, La Cavae et al. Sensory perception thresholds measurement. Archives of Physical Medicine and Rehabilitation 1987; 68: 499±507. 34. Procacci P, Bozza G, Buzzelli G et al. The cutaneous pricking threshold in old age. Gerontologia Clinica 1970; 12: 213±218. 35. Fich A, Camilleri M & Phillips SF. E€ect of age on human gastric and small bowel motility. Journal of Clinical Gastroenterology 1989; 11: 416±420. 36. James O. Aging and the alimentary tract. Gut 1997; 41: 421. 37. Lovat LB. Age related changes in gut physiology and nutritional status. Gut 1996; 41: 425±426. 38. Pfei€er RF. Gastrointestinal dysfunction in Parkinson's diseases. Clinical Neuroscience 1998; 5: 136±146. 39. Loening-Baucke V & Anuras S. Sigmoidal and rectal motility in healthy elderly. Journal of the American Geriatrics Society 1984; 32: 887±891. 40. Eastwood HD. Bowel transit studies in the elderly: radio-opaque markers in the investigation of constipation. Gerontalogia Clinica 1972; 14: 134±159. 41. Meier R, Beglinger C, Deberding J et al. In¯uence of age, gender, hormonal status and smoking status on colonic transit time. Neurogastroenterology and Motility 1995; 7: 235±238. 42. Melkerssen M, Andersson H, Bosacus I et al. Intestinal transit time in constipated and non-constipated geriatric patients. Scandinavian Journal of Gastroenterology 1983; 18: 593±597.

Irritable bowel syndrome in the elderly 75 43. Brocklehurst JC & Khan Y. A study of fecal stasis in old age and use of Dorbanex in its prevention. Gerontologia Clinica 1969; 2: 298. 44. Brocklehurst JC, Kirkland JL, Martin J et al. Constipation in longstay elderly patients: its treatment and prevention by lactulose, poloxalkol, dihydroxyanthraquinone and phosphate enema. Gerontology 1983; 29: 181±184. 45. Whitehead WE, Crowell MD, Robinson JC et al. E€ects of stressful life events on bowel symptoms: subjects with irritable bowel syndrome compared with subjects without bowel dysfunction. Gut 1992; 33: 825±830. 46. Kane SV, Sable K & Hanauer SB. The menstrual cycle and its e€ects in in¯ammatory bowel disease and irritable bowel syndrome: a prevalence study. American Journal of Gastroenterology 1998; 93: 1867±1872. 47. Fass R, Fullerton S, Tung S & Mayer EA. Sleep disturbances in clinic patients with functional bowel disturbances. American Journal of Gastroenterology 2000; 95: 1118±1121. 48. Thompson WG & Heaton KW. Functional bowel disorders in apparently healthy people. Gastroenterology 1980; 79: 283±288. 49. O'Keefe EA, Talley NJ, Zinsmeister AR et al. Does the irritable bowel syndrome burnout in the elderly? Gut 1990; 3: A1168 (Abstract). 50. Roberts RO, Lieber MM, Rhodes T et al. Prevalence pf a physician-assigned diagnosis of prostatitis: the Olmsted County Study of Urinary Symptoms and Health Status Among Men. Urology 1998; 51: 578±584. 51. Drossman DA, Sandler RS, Broom CM et al. Urgency and faecal soiling in people with bowel dysfunction. Digestive Diseases and Sciences 1986; 31: 1221±1225. 52. Whorwell PJ, McCallum M, Creed FH et al. Non-colonic features of irritable bowel syndrome. Gut 1986; 27: 37±40. 53. Kennedy TM, Jones RH, Hungin AP et al. Irritable bowel syndrome, gastro-oesophageal re¯ux, and bronchial hyper-responsiveness in the general population. Gut 1998; 43: 770±774. 54. Cukier JM, Cortina-Borja M & Brading AF. A case±control study to examine any association between detrusor instability and gastrointestinal tract disorder, and between irritable bowel syndrome and urinary tract disorder. British Journal of Urology 1997; 79: 865±878. 55. Monga AK, Marrero JM, Stanton SL et al. Is there an irritable bladder in the irritable bowel syndrome. British Journal of Obstetrics and Gynaecology 1997; 104: 1409±1412. 56. Ahlgren JD. Gastrointestinal cancer in the elderly. Clinics in Geriatric Medicine 1999; 15: 627±640. 57. Kay L & Avlund K. Abdominal syndromes and functional ability in the elderly. Aging (Milano) 1994; 6: 420±426. 58. Nagar A & Roberts M. Small bowel diseases in the elderly. Clinics in Geriatric Medicine 1999; 15: 473±486. 59. Holt PR, Rosenberg I & Russell R. Causes and consequences of hypochlorhydria in the elderly. Digestive Diseases and Sciences 1989; 34: 933±937. 60. Saltzman JR, Kowdley KV, Pedrosa MC et al. Bacterial overgrowth without clinical malabsorption in elderly hypochlorhydric subjects. Gastroenterology 1994; 106: 615±623. 61. Jailwala J, Imperiale TF & Kroenke K. Pharmacological treatment of the irritable bowel syndrome: a systematic review of randomized, controlled trials. Annals of Internal Medicine 2000; 13: 136±147. 62. Jackson JL, O'Malley PG, Tomkins G et al. Treatment of functional gastrointestinal disorders with antidepressant medications: a meta-analysis. American Journal of Medicine 2000; 108: 65±72. 63. Harari D, Gurwitz JH & Minaker JL. Constipation in the elderly. Journal of the American Geriatrics Society 1993; 41: 1130±1140. 64. Nolan L & O'Malley K. Prescribing for the elderly. Part 1: Sensitivity of the elderly adverse drug reactions. Journal of the American Geriatrics Society 1988; 36: 142±149. 65. Fassler CA, Rodriguez RM, Badesch DB et al. Magnesium toxicity as a cause of hypotension and hypoventilation. Occurrence in patients with normal renal function. Archives of Internal Medicine 1985; 145: 1604±1606. 66. Scheibel AB. Structural changes in the aging brain. In Birren JE, Slaone RB & Cohen GD (eds) Handbook of Mental Health and Aging, 2nd edn, pp 147±173. London: Academic Press, 1992. 67. Dawson D, Hendershot G & Fulton J. Ageing in the eighties: functional limitations of individuals aged 65 and over. National Center for Health Statistics Advance Data. US, Department of Health and Human Services. 1987; 133: 1±11. 68. Tinetti ME, Speechley M & Ginter SF. Risk factors for falls among elderly persons living in the community. New England Journal of Medicine 1988; 319: 1701±1707. 69. Thapa PB, Gideon P, Fought RL et al. Psychotropic drugs and the risk of recurrent falls in ambulatory nursing home residents. American Journal of Epidemiology 1995; 142: 202±211. 70. Chandler JM & Hadley EC. Gait and balance disorders: exercise to improve physiologic and functional performance in old age. Clinics in Geriatric Medicine 1996; 12: 761±784.

76 G. Bennett and N. J. Talley 71. Cumming RG, Thomas M, Szonyi G et al. Home visits by occupational therapists for assessment and modi®cation of environmental hazards: a randomized controlled trial of falls prevention. Journal of the American Geriatrics Society 1999; 47: 1397±1402. 72. Cartwright A & Smith C. Elderly People, Their Medications and Their Doctors. London: Routledge, 1988. 73. Simons LA, Tett S, Simons J et al. Multiple medication use in the elderly. Use of prescription and nonprescription drugs in an Australian community setting. Medical Journal of Australia 1992; 157: 242±246. 74. Sullivan DH. Nutrition, aging and age-dependent diseases: the role of nutrition is increased morbidity and mortality. Clinics in Geriatric Medicine 1995; 11: 661±674.