Insights into the pathophysiology and mechanisms of constipation, irritable bowel syndrome, and diverticulosis in older people

The human colon: Evidence for degenerative changes during aging and the physiological consequences

BACKGROUND

The incidence of constipation increases among the elderly (>65 years), while abdominal pain decreases. Causes include changes in lifestyle (e.g., diet and reduced exercise), disease and medications affecting gastrointestinal functions. Degenerative changes may also occur within the colo-rectum. However, most evidence is from rodents, animals with relatively high rates of metabolism and accelerated aging, with considerable variation in time course. In humans, cellular and non-cellular changes in the aging intestine are poorly investigated.

PURPOSE

To examine all available studies which reported the effects of aging on cellular and tissue functions of human isolated colon, noting the region studied, sex and age of tissue donors and study size. The focus on human colon reflects the ability to access full-thickness tissue over a wide age range, compared with other gastrointestinal regions. Details are important because of natural human variability. We found age-related changes within the muscle, in the enteric and nociceptor innervation, and in the submucosa. Some involve all regions of colon, but the ascending colon appears more vulnerable. Changes can be cell- and sublayer-dependent. Mechanisms are unclear but may include development of "senescent-like" and associated inflammaging, perhaps associated with increased mucosal permeability to harmful luminal contents. In summary, reduced nociceptor innervation can explain diminished abdominal pain among the elderly. Degenerative changes within the colon wall may have little impact on symptoms and colonic functions, because of high "functional reserve," but are likely to facilitate the development of constipation during age-related challenges (e.g., lifestyle, disease, and medications), now operating against a reduced functional reserve.

Bibliometric analysis of the 100 most-cited papers about the role of gut microbiota in irritable bowel syndrome from 2000 to 2021

AIM

Over the last few decades, gut microbiota research has been the focus of intense research and this field has become particularly important. This research aimed to provide a quantitative evaluation of the 100 most-cited articles on gut microbiota and IBS and highlight the most important advances in this field.

METHODS

The database Web of Science Core Collection was used to download the bibliometric information the top 100 most-cited papers. Microsoft Excel 2021, CiteSpace, VOSviewer, R software, and an online analytical platform ( https://bibliometric.com/ ) were was applied to perform bibliometric analysis of these papers.

RESULTS

The total citation frequency in the top 100 article ranged from 274 to 2324, with an average citation of 556.57. A total of 24 countries/regions made contributions to the top 100 cited papers, and USA, Ireland, and China were the most top three productive countries. Cryan JF was the most frequently nominated author, and of the top 100 articles, 20 listed his name. Top-cited papers mainly came from the Gastroenterology (n = 13, citations = 6373) and Gut (n = 9, citations = 3903). There was a significant citation path, indicating publications in molecular/biology/immunology primarily cited journals in molecular/biology/genetics fields. Keywords analysis suggested that the main topics on gut microbiota and IBS were mechanisms of microbiome in brain-gut axis." Behavior" was the keyword with the strongest burst strength (2.36), followed by "anxiety like behavior" (2.24), "intestinal microbiota" (2.19), and "chain fatty acid" (1.99), and "maternal separation" (1.95).

CONCLUSION

This study identified and provided the bibliometric information of the top 100 cited publications related to gut microbiota and IBS. The results provided a general overview of this topic and might help researchers to better understand the evolution, Influential findings and hotspots in researching gut microbiota and IBS, thus providing new perspectives and novel research ideas in this specific area.

Ageing and the Autonomic Nervous System

The vertebrate nervous system is divided into central (CNS) and peripheral (PNS) components. In turn, the PNS is divided into the autonomic (ANS) and enteric (ENS) nervous systems. Ageing implicates time-related changes to anatomy and physiology in reducing organismal fitness. In the case of the CNS, there exists substantial experimental evidence of the effects of age on individual neuronal and glial function. Although many such changes have yet to be experimentally observed in the PNS, there is considerable evidence of the role of ageing in the decline of ANS function over time. As such, this chapter will argue that the ANS constitutes a paradigm for the physiological consequences of ageing, as well as for their clinical implications.

Total collagen content and distribution is increased in human colon during advancing age

Background

The effect of ageing on total collagen content of human colon has been poorly investigated. The aim of this study was to determine if ageing altered total collagen content and distribution in the human colon.

Methods

Macroscopically normal ascending colon was obtained at surgery from cancer patients (n = 31) without diagnosis of diverticular disease or inflammatory bowel disease. Masson’s trichrome and Picrosirius red stains were employed to identify the total collagen content and distribution within the sublayers of the colonic wall for adult (22–60 years; 6 males, 6 females) and elderly (70 – 91years; 6 males, 4 female) patients. A hydroxyproline assay evaluated the total collagen concentration for adult (30–64 years; 9 male, 6 female) and elderly (66–91 years; 8 male, 8 female) patients.

Key results

Histological studies showed that the percentage mean intensity of total collagen staining in the mucosa, submucosa and muscularis externa was, respectively, 14(1.9) %, 74(3.2) % and 12(1.5) % in the adult ascending colon. Compared with the adults, the total collagen fibres content was increased in the submucosa (mean intensity; 163.1 ± 11.1 vs. 124.5 ± 7.8; P < 0.05) and muscularis externa (42.5 ± 8.0 vs. 20.6 ± 2.8; P < 0.01) of the elderly patients. There was no change in collagen content of the mucosa. The total collagen concentration was increased in the elderly by 16%. Sex-related differences were not found, and data were combined for analysis.

Conclusions

Greater total collagen content was found in the submucosa and muscularis externa of the elderly human male and female colon. These changes may contribute to a possible loss of function with ageing.

Microbiota-microglia connections in age-related cognition decline

Aging is an inevitable process that all individuals experience, of which the extent differs among individuals. It has been recognized as the risk factor of neurodegenerative diseases by affecting gut microbiota compositions, microglia, and cognition abilities. Aging‐induced changes in gut microbiota compositions have a critical role in orchestrating the morphology and functions of microglia through the gut‐brain axis. Gut microbiota communicates with microglia by its secreted metabolites and neurotransmitters. This is highly associated with age‐related cognitive declines. Here, we review the main composition of microbiota in the aged individuals, outline the changes of the brain in age‐related cognitive decline from a neuroinflammation perspective, especially the changes of morphology and functions of microglia, discuss the crosstalk between microbiota and microglia in the aged brain and further highlight the role of microbiota‐microglia connections in neurodegenerative diseases (Alzheimer's disease and Parkinson's disease).

The management of delirium in the older adult in advanced nursing practice

Delirium is a term used to describe an array of symptoms that indicate a disruption in cerebral metabolism, a condition that is often under-recognised, leading to delayed interventions. The condition is a common cause of older adults presenting in hospital, with significant morbidity and mortality associated with increased length of stay. A case study is used to illustrate the use of a diagnostic algorithm for older adults presenting with delirium to an advanced nurse practitioner (ANP)-led service. The clinical decision pathway provides four differential diagnoses, using the case study to put the decision-making process in context. The article demonstrates the ability of the ANP to practise at a high level of expertise as an autonomous practitioner and shows how the pathway supports the nurse to reach an accurate diagnosis. It shows that prompt and accurate diagnosis of delirium in older adults is crucial to avoiding the complications and cognitive decline associated with the condition.

The Relieving Effects of a Polyherb-Based Dietary Supplement ColonVita on Gastrointestinal Quality of Life Index (GIQLI) in Older Adults with Chronic Gastrointestinal Symptoms Are Influenced by Age and Cardiovascular Disease: A 12-Week Randomized Placebo-Controlled Trial

Chronic gastrointestinal symptoms (CGS) negatively affect the quality of life in about 15–30% of the population without effective drugs. Recent studies suggest that dietary supplement may improve CGS, but inconsistent results exist. The goal of this study is to evaluate the effect of a polyherbal-based supplement ColonVita on the gastrointestinal quality of life index (GIQLI) in 100 old adults with CGS (63.1 ± 9.6 years) who were randomly assigned to daily ColonVita or placebo tablets (n = 50/group) for 12 weeks in a double-blind, randomized controlled trial design. No significant fibrdifferences were found between ColonVita and placebo in the baseline total GIQLI score (101.12 ± 16.87 vs. 101.80 ± 16.48) (P > 0.05) or postintervention total GIQLI score (114.78 ± 9.62 vs. 111.74 ± 13.01) (P > 0.05). However, ColonVita significantly improved 16 scores of the 19 core GI symptoms compared with 10 items improved by placebo. The ColonVita group significantly improved the remission rate of 5 core GI symptoms compared to placebo and significantly improved the total GIQLI scores (118.09 ± 7.88 vs. 109.50 ± 16.71) (P < 0.05) and core GI symptom scores (64.61 ± 3.99 vs. 60.00 ± 8.65) (P < 0.05) in people ≥60 years of age (n = 49) but not in those under 60 y (n = 51). ColonVita significantly improved the total GIQLI scores and core GI symptom scores in people without cardiovascular diseases (CVD) (n = 56) (116.74 ± 9.38 vs. 110.10 ± 14.28) (P < 0.05) and (63.11 ± 4.53 vs. 59.93 ± 8.03) (P=0.07), respectively, but not in those with CVD (n = 44). Thus, ColonVita was beneficial for old adults with CGS, especially those ≥60 years of age and without CVD. Because a heterogenous pathogenesis of CGS-like irritable bowel syndrome (IBS) and inflammatory bowel disease (ISD) is differentially associated with CVD, different comorbidities may have influenced the outcomes of different trials that should be controlled in further studies.

Aging, Frailty, and the Microbiome-How Dysbiosis Influences Human Aging and Disease

The human gut microbiome is a collection of bacteria, protozoa, fungi, and viruses that coexist in our bodies and are essential in protective, metabolic, and physiologic functions of human health. Gut dysbiosis has traditionally been linked to increased risk of infection, but imbalances within the intestinal microbial community structure that correlate with untoward inflammatory responses are increasingly recognized as being involved in disease processes that affect many organ systems in the body. Furthermore, it is becoming more apparent that the connection between gut dysbiosis and age-related diseases may lie in how the gut microbiome communicates with both the intestinal mucosa and the systemic immune system, given that these networks have a common interconnection to frailty. We therefore discuss recent advances in our understanding of the important role the microbiome plays in aging and how this knowledge opens the door for potential novel therapeutics aimed at shaping a less dysbiotic microbiome to prevent or treat age-related diseases.

Enteroviruses in gastrointestinal diseases

Gastrointestinal diseases including diarrhoea constitute a major cause of morbidity and mortality in infants and young children especially in developing countries. Worldwide deaths among all ages due to diarrhoea during 2015 were estimated to be about 1.31 million, diarrhoeal deaths in children below 5 years of age being 499 000. Rotavirus accounted for about 200 000 deaths. Although diarrhoeal deaths decreased significantly during the last two decades, they still represent the third largest cause of infantile deaths. Several bacterial, viral, parasitic, fungal and non-infectious diarrhoea causing agents have been identified, but 30% to 40% of diarrhoeal cases remain undiagnosed. Enteroviruses transmit by the faecal-oral route and replicate first in intestinal cells before spreading to the target organ. They have been associated with diarrhoea in a few studies, but their causative role in diarrhoea in humans has not been systematically demonstrated. In view of the recent demonstration that enteroviruses cause diarrhoea in newborn mice pups, thus validating Koch's postulates, the purpose of this review is to emphasise the importance of recognising enteroviruses as major gastrointestinal pathogens associated with acute and persistent diarrhoea and non-diarrhoeal increased frequency of bowel movements in infants, young children and adults. Our studies and several other subsequent studies reported from different countries should stimulate strategies to reduce the burden of infantile gastrointestinal disease, which has hitherto remained unaddressed.

Adherence to the Saudi dietary guidelines and its relation to colorectal polyps: A university hospital-based study

Objectives

Colorectal polyps are a known precursor to colorectal cancer (CRC). Using the Saudi dietary guidelines adherence scores, this study evaluated whether dietary intake can lead to the development of colorectal polyps in a Saudi cohort.

Methods

In a cross-sectional study, 101 patients of both sexes, aged 30-86 years (40 patients with colorectal polyps and 61 patients without polyps), were recruited from the endoscopy unit in a Saudi hospital. A questionnaire was administered to collect demographic data, anthropometric data, and information about dietary habits.

Results

Patients with colorectal polyps were significantly older than those without polyps (p = 0.05). The mean body mass index in both patient groups was within the overweight range, with a value of 28.6 ± 6.7 kg/m². We did not find significant differences between patients with and without colorectal polyps. Although there was no difference in the overall scores for adherence to the Saudi dietary guidelines between the two groups, the specific adherence score for vegetables was significantly higher in patients without colorectal polyps (5.0 ± 0.0 vs. 4.9 ± 0.3, p = 0.03).

Conclusion

Ageing and lower vegetable intake, previously reported to be risk factors for CRC, were likewise identified in this study. However, a multi-centre study with a larger sample size, utilising data from this study, is needed.

Chronic Constipation in the Elderly Patient: Updates in Evaluation and Management

Chronic constipation (CC) is a common disorder in the elderly population globally and is associated with comorbidities and negative implications on the quality of life. Constipation prevalence varies in different studies, primarily owing to the nonuniformity of the diagnostic criteria. However, 15%-30% of individuals aged >60 years are diagnosed with CC. Primary care physicians are the main healthcare providers that manage constipation in elderly patients in parallel with increased population aging and increased prevalence of constipation. Physical inactivity, polypharmacy, chronic medical conditions, rectal hyposensitivity, and defecatory disorders all play a role in the pathogenesis of CC in elderly patients. Detailed anamnesis, particularly history related to chronic medication use, with digital rectal examination may assist in identifying constipation causes. Additionally, blood tests and colonoscopy may identify organic causes of CC. Physiologic tests (i.e., anorectal manometry, colonic transit time with radiopaque markers, and defecography) can evaluate the physiologic function of the colon, rectum, and anus. However, generally, there are several causes of constipation in older patients, and an individualized approach is recommended. Treatment of chronic idiopathic constipation is empiric, based on the stepwise approach. Lifestyle advice, adjustment of chronic medications, and prescription of laxatives are the first steps of management. Several laxatives are available, and the treatment is evolving in the last decade. Biofeedback is an effective therapy especially for defecatory disorders. This review aimed to summarize the most updated knowledge for primary care physicians in the approach and management of CC in elderly patients.

Association between Irritable Bowel Syndrome and Allergic Diseases: To Make a Case for Aeroallergen

Irritable bowel syndrome (IBS) is a functional gastrointestinal disease and the most common cause of prolonged abdominal pain and bowel disturbances in the developed world. While initially thought to be functional or psychosomatic in nature, IBS is now recognized as a heterogeneous group of conditions. A subset of IBS patients and patients with allergic diseases share some characteristic inflammatory features. In fact, atopic children show an increased likelihood of developing IBS as adults. Given these findings, a subset of IBS may be suffering from allergy-related gut diseases. In this review, we present the allergy-related comorbidities of IBS, including genetic, environmental, and immunologic factors. We discuss studies demonstrating an increased sensitization of IBS patients to aeroallergens compared to food allergens. We then postulate potential pathophysiological mechanisms underlying both IBS and aeroallergens in the gut, followed by potential implications in the screening and treatment of allergies in IBS patients.

Diverticular disease epidemiology: acute hospitalisations are growing fastest in young men

BACKGROUND

Older age has long been linked to risk of diverticulitis, but the epidemiology is seldom described for a national population. The aim of this study was to investigate age- and gender differences in incidence, temporal trends, lifetime risk and prevalence related to acute diverticulitis hospitalisations in New Zealand.

METHODS

Records of all hospitalisations with diverticulitis the primary diagnosis were obtained from the Ministry of Health for the period 2000-2015. The first acute diverticulitis admission recorded for an individual was taken as an incident event; all others were classified as recurrent. Trends in age- and sex-specific and age-standardised incidence rates are described, and lifetime risk and prevalence estimated.

RESULTS

Over the 16 years from 2000 to 2015, 37,234 acute hospitalisations for diverticulitis were recorded in 28,329 people aged 30 + years (median = 66 years). Rates of incident hospitalisations rose with age, from 5/10,000 person-years at age 50-54 years to 19/10,000py by age 80-84 years. Rates for women were lower than men before age 55 years, but higher thereafter. Age-standardised rates rose 0.2/10,000py annually, but approximately doubled among men aged < 50 years. Lifetime risk was estimated at over 5%, with the prevalence pool rising to over 1.5% of the population aged 30+ in 2030.

CONCLUSIONS

Rapid increases in diverticulitis admissions among young men since 2000 correspond with increases reported elsewhere but remain unexplained; notably young women follow similar trends 5-10 years later. Increasing incidence, combined with population ageing, adds urgency to explain diverticular formation, to understand factors that trigger or provoke their inflammation/infection, and to clarify treatment and (self-)management pathways.

Changes in neuromuscular structure and functions of human colon during ageing are region-dependent

OBJECTIVE

To determine if human colonic neuromuscular functions decline with increasing age.

DESIGN

Looking for non-specific changes in neuromuscular function, a standard burst of electrical field stimulation (EFS) was used to evoke neuronally mediated (cholinergic/nitrergic) contractions/relaxations in ex vivomuscle strips of human ascending and descending colon, aged 35-91 years (macroscopically normal tissue; 239 patients undergoing cancer resection). Then, to understand mechanisms of change, numbers and phenotype of myenteric neurons (30 306 neurons stained with different markers), densities of intramuscular nerve fibres (51 patients in total) and pathways involved in functional changes were systematically investigated (by immunohistochemistry and use of pharmacological tools) in elderly (≥70 years) and adult (35-60 years) groups.

RESULTS

With increasing age, EFS was more likely to evoke muscle relaxation in ascending colon instead of contraction (linear regression: n=109, slope 0.49%±0.21%/year, 95% CI), generally uninfluenced by comorbidity or use of medications. Similar changes were absent in descending colon. In the elderly, overall numbers of myenteric and neuronal nitric oxide synthase-immunoreactive neurons and intramuscular nerve densities were unchanged in ascending and descending colon, compared with adults. In elderly ascending, not descending, colon numbers of cell bodies exhibiting choline acetyltransferase immunoreactivity increased compared with adults (5.0±0.6 vs 2.4±0.3 neurons/mm myenteric plexus, p=0.04). Cholinergically mediated contractions were smaller in elderly ascending colon compared with adults (2.1±0.4 and 4.1±1.1 g-tension/g-tissue during EFS; n=25/14; p=0.04); there were no changes in nitrergic function or in ability of the muscle to contract/relax. Similar changes were absent in descending colon.

CONCLUSION

In ascending not descending colon, ageing impairs cholinergic function.

Subclinical Hypothyroidism: is it Really Subclinical with Aging?

No recent study has focused on clinical features of subclinical hypothyroidism (SCH), especially in older patients. TSH measurement has remarkably evolved these last 20 years and thus reconsideration is needed. In our prospective multicenter study (2012-2014) including 807 subjects aged <60 years (<60y) and 531 subjects ≥60 years (≥60y), we have monitored 11 hypothyroidism-related clinical signs (hCS) together with TSH, FT4, FT3 and anti-thyroperoxidase antibodies values. hCS expression has been compared in patients with SCH vs euthyroidism in each age group. The number of hCS above 60y of age were found to be more elevated in the euthyroid population (1.9 vs 1.6, p<0.01) than in the SCH population (2.3 vs 2.6, p=0.41) while increase in hCS is limited to SCH subjects in the <60y group (p<0.01). The percentage of subjects with at least 3 signs increased with SCH in the <60y group (42.6% vs 25.0%, p<0.01) but not ≥60y (34.4% vs 33.9%, p=0.96). In older individuals, only three hCS could be related to both SCH and a decreased T3/T4-ratio (0.26 vs 0.27, p<0.01), suggesting either a reduced activity of TSH, or an adaptive response with aging. While hCS are clearly associated with SCH in patients <60y, they are not so informative in older subjects. TSH measurements carried out on the basis of hCS need to be interpreted with caution in aged patients. A reassessment of the TSH reference range in older patients is clearly needed and should be associated to more appropriate monitoring of thyroid dysfunction

Microbes and the Mind: How Bacteria Shape Affect, Neurological Processes, Cognition, Social Relationships, Development, and Pathology

Recent data suggest that the human body is not so exclusively human after all. Specifically, humans share their bodies with approximately 10 trillion microorganisms, collectively known as the microbiome. Chief among these microbes are bacteria, and there is a growing consensus that they are critical to virtually all facets of normative functioning. This article reviews the ways in which bacteria shape affect, neurological processes, cognition, social relationships, development, and psychological pathology. To date, the vast majority of research on interactions between microbes and humans has been conducted by scientists outside the field of psychology, despite the fact that psychological scientists are experts in many of the topics being explored. This review aims to orient psychological scientists to the most relevant research and perspectives regarding the microbiome so that we might contribute to the now widespread, interdisciplinary effort to understand the relationship between microbes and the mind.

Diverticular Perforation Secondary to a Chicken Bone: Food for Thought

A 56-year-old man presented to the emergency department with a one-day history of lower abdominal pain and fever. Clinical examination revealed generalized peritonitis. A computed tomography (CT) scan identified a linear hyperdensity straddling the site of a perforated sigmoid diverticulum. The patient proceeded to emergency laparotomy, which confirmed feculent peritonitis secondary to chicken bone perforation through the sigmoid colon diverticulum. After removal of the bone, Hartmann’s procedure was performed, and the patient subsequently made an excellent recovery.

The urinary phenolic acid profile varies between younger and older adults after a polyphenol-rich meal despite limited differences in in vitro colonic catabolism

PURPOSE

To investigate whether age influences colonic polyphenol metabolism.

METHODS

Healthy participants, younger (n = 8; 23-43 years) and older (n = 13; 51-76 years), followed a 3-day low-polyphenol diet (LPD) and a 3-day high-polyphenol diet (HPD). Urinary phenolic acids (PA), short chain fatty acids (SCFA), pH and gas were monitored, alongside selected colonic bacteria. Human faecal in vitro fermentations of rutin with or without raftiline were used to evaluate the gut microbiota capacity in a subset of both groups.

RESULTS

Total urinary PA were higher in the older group after HPD compared to the younger group (1.5-fold; p = 0.04), with no difference between groups in terms of a change between diets (Δ high-low diet). While 17 PA were detected in all younger participants after HPD, a narrower range (n = 8 to 16 PA) was detected in most (n = 9/13) older participants, with lower level of benzoic acid (19-fold; p = 0.03), vanillic acid (4.5-fold; p = 0.04) but higher hippuric acid (2.7-fold; p = 0.03). Faecal SCFA concentration did not change after HPD within group, with similar differential excretion (Δ high-low diet) between groups. There were no differences between groups for faecal pH, total, faecal bacteria including Flavonifractor plautii, bifidobacteria, and bacteroides. In human in vitro faecal fermentations, seven PAs were detected in both groups after 24 h of rutin fermentation, with no quantitative and modest qualitative differences between groups. Total SCFA in faecal fermentation did not differ between groups, except for butyric acid (twofold higher in the older group; p = 0.009) when rutin was fermented with raftiline over 24 h.

CONCLUSIONS

Urinary phenolic acids were less diverse in older participants despite limited difference in functional capacity of in vitro faecal fermentations.

Comparison of Changes in the Interstitial Cells of Cajal and Neuronal Nitric Oxide Synthase-positive Neuronal Cells With Aging Between the Ascending and Descending Colon of F344 Rats

Background/Aims

Neuronal degeneration and changes in interstitial cells of Cajal (ICCs) are important mechanisms of age-related constipation. This study aims to compare the distribution of ICCs and neuronal nitric oxide synthase (nNOS) with regard to age-related changes between the ascending colon (AC) and descending colon (DC) in 6-, 31-, and 74-week old and 2-year old male Fischer-344 rats.

Methods

The amount of fecal pellet and the bead expulsion times were measured. Fat proportion in the muscle layer of the colon was analyzed by hematoxylin and eosin staining. Proto-oncogene receptor tyrosine kinase (KIT) and neuronal nitric oxide synthase (nNOS) expression were analyzed with Western blotting and immunohistochemistry. Isovolumetric contractile measurements and electrical field stimulation were used to assess smooth muscle contractility.

Results

Colon transit and bead expulsion slowed with senescence. Fat in the muscle layer accumulated with age in the AC, but not in the DC. The proportion of KIT-immunoreactive ICCs in the submucosal and myenteric plexus was higher in the DC than in the AC, and it declined with age, especially in the AC. In contrast, the proportion of NOS-immunoreactive neurons in the myenteric plexus was higher in the AC than in the DC, and both decreased in older rats. Nitric oxide levels declined with age in the DC. Muscle strip experiments showed that the inhibitory response mediated by nitric oxide in the circular direction of the DC was reduced in 2-year old rats.

Conclusion

The AC and DC differ in their distribution of ICCs and nNOS, and age-related loss of nitrergic neurons more severely affects the DC than the AC.

Intractable Constipation in the Elderly

OPINION STATEMENT

Chronic constipation is a common gastrointestinal disorder disproportionately affecting the elderly. Immobility, polypharmacy, and physiologic changes contribute to its increased prevalence in this population. Unidentified and undertreated constipation leads to a significant negative impact on quality of life and an increase in healthcare spending. Careful physical examination and exploration of the clinical history can unmask primary and secondary forms of constipation, guiding diagnostic and therapeutic considerations. Non-pharmacologic treatment options include bowel training and biofeedback as well as the addition of fiber. Laxatives are safe and can be used long term; thus, they remain the mainstay of therapy. Newer agents with specific physiologic targets have proven to be effective in adults with chronic constipation, but data is lacking for safety profile in the elderly. Consideration for surgery in medically refractory cases should be entertained, while use of neuromodulation is not ready for prime time. This is a review of the currently available treatment options for chronic constipation in adults and specifically tailored towards the elderly.

Gastrointestinal Dysmotility in the Elderly

The number of persons 60 years and older has increased 3-fold between 1950 and 2000. Aging alone does not greatly impact the gastrointestinal (GI) tract. Digestive dysfunction, including esophageal reflux, achalasia, dysphagia, dyspepsia, delayed gastric emptying, constipation, fecal incontinence, and fecal impaction, is a result of the highly prevalent comorbid conditions and the medications with which those conditions are treated. A multidisciplinary approach with the expertise of a geriatrician, gastroenterologist, neurologist, speech pathologist, and physical therapist ensures a comprehensive functional and neurological assessment of the older patient. Radiographic and endoscopic evaluation may be warranted in the evaluation of the symptomatic older patient with consideration given to the risks and benefits of the test being used. Treatment of the digestive dysfunction is aimed at improving health-related quality of life if cure cannot be achieved. Promotion of healthy aging, treatment of comorbid conditions, and avoidance of polypharmacy may prevent some of these digestive disorders. The age-related changes in GI motility, clinical presentation of GI dysmotility, and therapeutic principles in the symptomatic older patient are reviewed here.

Age-related changes in gut microbiota composition from newborn to centenarian: a cross-sectional study

BACKGROUND

It has been reported that the composition of human gut microbiota changes with age; however, few studies have used molecular techniques to investigate the long-term, sequential changes in gut microbiota composition. In this study, we investigated the sequential changes in gut microbiota composition in newborn to centenarian Japanese subjects.

RESULTS

Fecal samples from 367 healthy Japanese subjects between the ages of 0 and 104 years were analyzed by high-throughput sequencing of amplicons derived from the V3-V4 region of the 16S rRNA gene. Analysis based on bacterial co-abundance groups (CAGs) defined by Kendall correlations between genera revealed that certain transition types of microbiota were enriched in infants, adults, elderly individuals and both infant and elderly subjects. More positive correlations between the relative abundances of genera were observed in the elderly-associated CAGs compared with the infant- and adult-associated CAGs. Hierarchical Ward's linkage clustering based on the abundance of genera indicated five clusters, with median (interquartile range) ages of 3 (0-35), 33 (24-45), 42 (32-62), 77 (36-84) and 94 (86-98) years. Subjects were predominantly clustered with their matched age; however, some of them fell into mismatched age clusters. Furthermore, clustering based on the proportion of transporters predicted by phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) showed that subjects were divided into two age-related groups, the adult-enriched and infant/elderly-enriched clusters. Notably, all the drug transporters based on Kyoto Encyclopedia of Genes and Genomes (KEGG) Orthology groups were found in the infant/elderly-enriched cluster.

CONCLUSION

Our results indicate some patterns and transition points in the compositional changes in gut microbiota with age. In addition, the transporter property prediction results suggest that nutrients in the gut might play an important role in changing the gut microbiota composition with age.

Gastrointestinal Microbiota and Their Contribution to Healthy Aging

Studies on populations at different ages have shown that after birth, the gastrointestinal (GI) microbiota composition keeps evolving, and this seems to occur especially in old age. Significant changes in GI microbiota composition in older subjects have been reported in relation to diet, drug use and the settings where the older subjects are living, that is, in community nursing homes or in a hospital. Moreover, changes in microbiota composition in the old age have been related to immunosenescence and inflammatory processes that are pathophysiological mechanisms involved in the pathways of frailty. Frailty is an age-related condition of increased vulnerability to stresses due to the impairment in multiple inter-related physiologic systems that are associated with an increased risk of adverse outcomes, such as falls, delirium, institutionalization, hospitalization and death. Preliminary data suggest that changes in microbiota composition may contribute to the variations in the biological, clinical, functional and psycho-social domains that occur in the frail older subjects. Multidimensional evaluation tools based on a Comprehensive Geriatric Assessment (CGA) have demonstrated to be useful in identifying and measuring the severity of frailty in older subjects. Thus, a CGA approach should be used more widely in clinical practice to evaluate the multidimensional effects potentially related to GI microbiota composition of the older subjects. Probiotics have been shown to be effective in restoring the microbiota changes of older subjects, promoting different aspects of health in elderly people as improving immune function and reducing inflammation. Whether modulation of GI microbiota composition, with multi-targeted interventions, could have an effect on the prevention of frailty remains to be further investigated in the perspective of improving the health status of frail 'high risk' older individuals.

Chronic constipation in the elderly: a primer for the gastroenterologist

Constipation is a frequently reported bowel symptom in the elderly with considerable impact on quality of life and health expenses. Disease-related morbidity and even mortality have been reported in the affected frail elderly. Although constipation is not a physiologic consequence of normal aging, decreased mobility, medications, underlying diseases, and rectal sensory-motor dysfunction may all contribute to its increased prevalence in older adults. In the elderly there is usually more than one etiologic mechanism, requiring a multifactorial treatment approach. The majority of patients would respond to diet and lifestyle modifications reinforced by bowel training measures. In those not responding to conservative treatment, the approach needs to be tailored addressing all comorbid conditions. In the adult population, the management of constipation continues to evolve as well as the understanding of its complex etiology. However, the constipated elderly have been left behind while gastroenterology consultations for this common conditions are at a rise for the worldwide age increment. Aim of this review is to provide an update on epidemiology, quality of life burden, etiology, diagnosis, current approaches and limitations in the management of constipation in the older ones to ease the gastroenterologists’ clinic workload.

Epidemiology and management of chronic constipation in elderly patients

Constipation is a common functional gastrointestinal disorder, with prevalence in the general population of approximately 20%. In the elderly population the incidence of constipation is higher compared to the younger population, with elderly females suffering more often from severe constipation. Treatment options for chronic constipation (CC) include stool softeners, fiber supplements, osmotic and stimulant laxatives, and the secretagogues lubiprostone and linaclotide. Understanding the underlying etiology of CC is necessary to determine the most appropriate therapeutic option. Therefore, it is important to distinguish from pelvic floor dysfunction (PFD), slow and normal transit constipation. Evaluation of a patient with CC includes basic blood work, rectal examination, and appropriate testing to evaluate for PFD and slow transit constipation when indicated. Pelvic floor rehabilitation or biofeedback is the treatment of choice for PFD, and its efficacy has been proven in clinical trials. Surgery is rarely indicated in CC and can only be considered in cases of slow transit constipation when PFD has been properly excluded. Other treatment options such as sacral nerve stimulation seem to be helpful in patients with urinary dysfunction. Botulinum toxin injection for PFD cannot be recommended at this time with the available evidence. CC in the elderly is common, and it has a significant impact on quality of life and the use of health care resources. In the elderly, it is imperative to identify the etiology of CC, and treatment should be based on the patient’s overall clinical status and capabilities.

Non-diarrhoeal increased frequency of bowel movements (IFoBM-ND): enterovirus association with the symptoms in children

OBJECTIVE

Infectious and non-infectious causes are associated with increased frequency of bowel movements (IFoBM). But, a viral aetiology to non-diarrhoeal IFoBM (IFoBM-ND) has not been described. Owing to an accidental infection by an echovirus 19 strain, persistent diarrhoea-associated virus, isolated from a child with persistent diarrhoea, DCR experienced persistent IFoBM-ND with an urgency to pass apparently normal stools more than once each day for about 3 months. A follow-up study was undertaken to determine the prevalence of IFoBM-ND, and association of non-polio enteroviruses (NPEVs) with the symptom in infants from birth to 2 years.

DESIGN

A cohort of 140 newborns was followed for 6 months to 2 years from birth for IFoBM-ND. Stool samples collected every 14 days were examined for NPEVs, rotavirus and other viral/bacterial agents for their possible association with IFoBM-ND and diarrhoea.

RESULTS

Of 403 NPEV infection episodes among 4545 oral polio vaccine strains-negative stool samples, approximately 29% were associated with IFoBM-ND (15% acute and 14% persistent), including resolution of 74% of constipation episodes, and 18% with diarrhoea, suggesting that about 47% of NPEV infection episodes in children below 2 years of age are associated with gastrointestinal symptoms. About 83% of IFoBM-ND episodes are associated with the NPEV infection and 17% of the episodes are of unknown aetiology.

CONCLUSIONS

NPEV is the single most frequently detected viral agent in children with IFoBM-ND and its association with the symptom is highly significant, warranting detailed investigations on the role of NPEVs in gastrointestinal diseases.

Endoscopy in the elderly: risks, benefits, and yield of common endoscopic procedures

There has been limited research examining the risks, benefits, and use of common endoscopic procedures in the elderly. Furthermore, gastroenterology training programs do not routinely incorporate elderly concerns when dealing with common gastrointestinal issues. There exists a broad array of endoscopic procedures with varying inherent risks that must be weighed with each elderly patient in mind. This article discusses the benefits and drawbacks of the most common procedures and indications for endoscopy including upper endoscopy, colonoscopy, endoscopic retrograde cholangiopancreatography, endoscopic ultrasound, percutaneous endoscopic gastrostomy, and deep enteroscopy.

Urogenital consequences in ageing women

Various anatomical, physiological, genetic, lifestyle and reproductive factors interact throughout a woman's life span and contribute to pelvic floor disorders. Ageing affects pelvic floor anatomy and function, which can result in a variety of disorders, such as pelvic organ prolapse, lower urinary tract symptoms, dysfunctional bowel and bladder evacuation, and sexual dysfunction. The exact mechanisms and pathophysiological processes by which ageing affects pelvic floor and lower urinary and gastrointestinal tract anatomy and function are not always clear. In most cases, it is difficult to ascertain the exact role of ageing per se as an aetiological, predisposing or contributing factor. Other conditions associated with ageing that may co-exist, such as changes in mental status, can result in different types of pelvic floor dysfunction (e.g. functional incontinence). Pelvic organ dysfunction may be associated with significant morbidity and affect quality of life. These groups of patients often pose difficult diagnostic and therapeutic dilemmas owing to complex medical conditions and concurrent morbidities. In this chapter, we summarise the current evidence on the management of pelvic floor disorders, with emphasis on elderly women and the associations between the ageing process and these disorders. Clinicians with an understanding of the affect of ageing on the pelvic floor and lower urinary and gastrointestinal tract anatomy and function, and the complex interplay of other comorbidities, will be able to investigate, diagnose and treat appropriately there women. A holistic approach may result in substantial improvements in their quality of life.

A critical appraisal of lubiprostone in the treatment of chronic constipation in the elderly

Chronic constipation is a common disorder in the general population, with higher prevalence in the elderly, and is associated with worse quality of life and with greater health care utilization. Lubiprostone is an intestinal type-2 chloride channel activator that increases intestinal fluid secretion, small intestinal transit, and stool passage. Lubiprostone is currently approved by the US Food and Drug Administration for the treatment of chronic idiopathic constipation and of irritable bowel syndrome with predominant constipation. This review outlines current approaches and limitations in the treatment of chronic constipation in the elderly and discusses the results, limitations, and applicability of randomized, controlled trials of lubiprostone that have been conducted in the general and elderly population, with additional focus on the use of lubiprostone in constipation in Parkinson's disease and in opioid-induced constipation, two clinical entities that can be comorbid in elderly patients.

Aging impairs Ca2+ sensitization pathways in gallbladder smooth muscle

Calcium sensitization is an important physiological process in agonist-induced contraction of smooth muscle. In brief, calcium sensitization is a pathway that leads to smooth muscle contraction independently of changes in [Ca(2+)](i) by mean of inhibition of myosin light chain phosphatase. Aging has negative impacts on gallbladder contractile response due to partial impairment in calcium signaling and alterations in the contractile machinery. However, information regarding aging-induced alterations in calcium sensitization is scanty. We hypothesized that the calcium sensitization system is negatively affected by age. To investigate this, gallbladders were collected from adult (4 months old) and aged (22-24 months old) guinea pigs. To evaluate the contribution of calcium sensitization pathways we assayed the effect of the specific inhibitors Y-27632 and GF109203X on the "in vitro" isometric gallbladder contractions induced by agonist challenges. In addition, expression and phosphorylation (as activation index) of proteins participating in the calcium sensitization pathways were quantified by Western blotting. Aging reduced bethanechol- and cholecystokinin-evoked contractions, an effect associated with a reduction in MLC20 phosphorylation and in the effects of both Y-27632 and GF109203X. In addition, there was a drop in ROCK I, ROCK II, MYPT-1 and PKC expression and in the activation/phosphorylation of MYPT-1, PKC and CPI-17 in response to agonists. Interestingly, melatonin treatment for 4 weeks restored gallbladder contractile responses due to re-establishment of calcium sensitization pathways. These results demonstrate that age-related gallbladder hypocontractility is associated to alterations of calcium sensitization pathways and that melatonin treatment exerts beneficial effects in the recovery of gallbladder contractility.

A global perspective on irritable bowel syndrome: a consensus statement of the World Gastroenterology Organisation Summit Task Force on irritable bowel syndrome

Irritable bowel syndrome (IBS) is common in western Europe and North America, and many aspects of its epidemiology, risk factors, and natural history have been described in these regions. Recent data suggest, however, that IBS is also common in the rest of the world and there has been some evidence to suggest some differences in demographics and presenting features between IBS in the west and as it is experienced elsewhere. The World Gastroenterology Organization, therefore, established a Task Force comprising experts on the topic from all parts of the world to examine IBS from a global perspective. IBS does, indeed, seem to be common worldwide though with some significant variations in prevalence rates between regions and countries and there may well be some potentially interesting variations in presenting symptoms and sex distribution. The global map of IBS is far from complete; community-based prevalence data is not available from many areas. Furthermore, while some general trends are evident in terms of IBS impact and demographics, international comparisons are hampered by differences in diagnostic criteria, study location and methodology; several important unanswered questions have been identified that should form the basis for future collaborative research and have the potential to shed light on this challenging disorder.

Colorectal and uterine movement and tension of the inferior hypogastric plexus in cadavers

BACKGROUND

Hypotheses on somatovisceral dysfunction often assume interference by stretch or compression of the nerve supply to visceral structures. The purpose of this study is to examine the potential of pelvic visceral movement to create tension of the loose connective tissue that contains the fine branches of the inferior hypogastric nerve plexus.

METHODS

Twenty eight embalmed human cadavers were examined. Pelvic visceral structures were displaced by very gentle 5 N unidirectional tension and the associated movement of the endopelvic fascia containing the inferior hypogastric plexus that this caused was measured.

RESULTS

Most movement of the fascia containing the inferior hypogastric plexus was obtained by pulling the rectosigmoid junction or broad ligament of the uterus. The plexus did not cross any vertebral joints and the fascia containing it did not move on pulling the hypogastric nerve.

CONCLUSIONS

Uterine and rectosigmoid displacement produce most movement of the fascia containing the hypogastric nerve plexus, potentially resulting in nerve tension. In the living this might occur as a consequence of menstruation, pregnancy or constipation. This may be relevant to somatovisceral reflex theories of the effects of manual therapy on visceral conditions.

Characterization of motor patterns in isolated human colon: are there differences in patients with slow-transit constipation?

The patterns of motor activity that exist in isolated full-length human colon have not been described. Our aim was to characterize the spontaneous motor patterns in isolated human colon and determine whether these patterns are different in whole colons obtained from patients with slow-transit constipation (STC). The entire colon (excluding the anus), was removed from patients with confirmed STC and mounted longitudinally in an organ bath ∼120 cm in length, containing oxygenated Krebs' solution at 36°C. Changes in circular muscle tension were recorded from multiple sites simultaneously along the length of colon, by use of isometric force transducers. Recordings from isolated colons from non-STC patients revealed cyclical colonic motor complexes (CMCs) in 11 of 17 colons, with a mean interval and half-duration of contractions of 4.0 ± 0.6 min and 51.5 ± 15 s, respectively. In the remaining six colons, spontaneous irregular phasic contractions occurred without CMCs. Interestingly, in STC patients robust CMCs were still recorded, although their CMC pacemaker frequencies were slower. Intraluminal balloon distension of the ascending or descending colon evoked an ascending excitatory reflex contraction, or evoked CMC, in 8 of 30 trials from non-STC (control) colons, but not from colons obtained from STC patients. In many control segments of descending colon, spontaneous CMCs consisted of simultaneous ascending excitatory and descending inhibitory phases. In summary, CMCs can be recorded from isolated human colon, in vitro, but their intrinsic pacemaker frequency is considerably faster in vitro compared with previous human recordings of CMCs in vivo. The observation that CMCs occur in whole colons removed from STC patients suggests that the intrinsic pacemaker mechanisms underlying their generation and propagation are preserved in vitro, despite impaired transit along these same regions in vivo.

Chronic constipation in the elderly

Constipation is one of the most frequent gastrointestinal disorders encountered in clinical practice in Western societies. Its prevalence increases with age and is more frequently reported in female patients. Chronic constipation has been associated with considerable impairment in quality of life, can result in large individual healthcare costs, and represents a burden to healthcare delivery systems. This review will focus on the definition, epidemiology, diagnostic approach, and non-pharmacologic as well as pharmacologic management of chronic constipation in the elderly, including an overview of new medications currently under clinical investigation.

Melatonin, and to a lesser extent growth hormone, restores colonic smooth muscle physiology in old rats

There is increasing evidence that aging is associated with oxidative damage, inflammation, and apoptosis in different cell types. However, there is limited information regarding aging mechanisms in colon smooth muscle. Old male Wistar rats (22 months) were treated for 10 wks with melatonin or growth hormone (GH). Animals were sacrificed at 24 months of age by decapitation. The colon was dissected and the smooth muscle homogenized. H(2)O(2) and malonyl dialdehyde (MDA) content and catalase and glutathione peroxidase (GPX) activities were determined using colorimetric kits. Expression of nuclear factor kappa B (NF-κB), cyclooxygenase 2 (COX-2), caspase-3, and caspase-9 were determined by Western blot. Aging of colon smooth muscle correlated with an increase in H(2)O(2) and MDA levels when compared with young animals in both proximal and distal segments; these changes were associated with a decrease in the catalase activity in the distal colon. Oxidative stress correlated with an increase in COX-2 and NF-κB expression, which were accompanied by an enhanced expression of the pro-apoptotic enzyme caspase-3 and its upstream enzyme, caspase-9. Melatonin treatment normalized the oxidative, inflammatory, and apoptotic patterns, whereas GH replacement, although effective in reducing oxidative stress in distal colon, did not reverse the age-related inflammation or apoptosis. These results suggest that melatonin should be the treatment of choice to most effectively recover physiological functions in aged colonic smooth muscle.

Epidemiology of functional constipation and comparison with constipation-predominant irritable bowel syndrome: the Systematic Investigation of Gastrointestinal Diseases in China (SILC)

BACKGROUND

The epidemiology and effects of functional constipation (FC) on Chinese people remain unclear.

AIM

To investigate the epidemiology of FC and its distinction from constipation-predominant irritable bowel syndrome (IBS-C) in China.

METHODS

A cross-sectional survey was conducted in a representative adult Chinese population (n = 16,078), which was selected from five regions using randomised, stratified, multistage sampling methodology. All respondents completed the modified Rome II questionnaire; 20% were asked to complete the 36-item Short Form (SF-36) and the Epworth Sleepiness Scale (ESS).

RESULTS

Overall, 948 respondents (6%) had FC and FC was more prevalent in women than in men (8% vs. 4%, P < 0.001). Straining and hard stools were the two most frequent symptoms. FC was associated significantly with dyspepsia and abdominal bloating. All SF-36 domain scores were lower for respondents with FC than for those without. The prevalence of clinically meaningful daytime sleepiness was significantly higher in respondents with FC than in those without (22% vs. 14%, P = 0.003). Respondents with FC were more likely to strain, but less likely to have a feeling of incomplete emptying after a bowel movement than those with IBS-C. Respondents with IBS-C experienced similar demographics, quality of life and daytime sleepiness to those with FC.

CONCLUSIONS

The prevalence of FC in China is substantially lower than that in Western countries. FC has negative effects on quality of life and daytime sleepiness. The demographics and burden of illness are similar between FC and IBS-C, although the clinical symptoms are somewhat different.

Composition, variability, and temporal stability of the intestinal microbiota of the elderly

Alterations in the human intestinal microbiota are linked to conditions including inflammatory bowel disease, irritable bowel syndrome, and obesity. The microbiota also undergoes substantial changes at the extremes of life, in infants and older people, the ramifications of which are still being explored. We applied pyrosequencing of over 40,000 16S rRNA gene V4 region amplicons per subject to characterize the fecal microbiota in 161 subjects aged 65 y and older and 9 younger control subjects. The microbiota of each individual subject constituted a unique profile that was separable from all others. In 68% of the individuals, the microbiota was dominated by phylum Bacteroides, with an average proportion of 57% across all 161 baseline samples. Phylum Firmicutes had an average proportion of 40%. The proportions of some phyla and genera associated with disease or health also varied dramatically, including Proteobacteria, Actinobacteria, and Faecalibacteria. The core microbiota of elderly subjects was distinct from that previously established for younger adults, with a greater proportion of Bacteroides spp. and distinct abundance patterns of Clostridium groups. Analyses of 26 fecal microbiota datasets from 3-month follow-up samples indicated that in 85% of the subjects, the microbiota composition was more like the corresponding time-0 sample than any other dataset. We conclude that the fecal microbiota of the elderly shows temporal stability over limited time in the majority of subjects but is characterized by unusual phylum proportions and extreme variability.

Chronic constipation: lessons from animal studies

Chronic constipation is a highly debilitating condition, affecting a significant proportion of the community. The burden to the health care system and impact on individual patients quality of life is immense. Unfortunately, the aetiology underlying chronic constipation is poorly understood and animal models are being used increasingly to investigate possible intrinsic neurogenic and myogenic mechanisms leading to relevant colonic sensori-motor dysfunction. Recently, major advances have been made in our understanding of the mechanisms that underlie propagating contractions along the large intestine, such as peristalsis and colonic migrating motor complexes in laboratory animals, particularly in guinea-pigs and mice. The first recordings of cyclical propagating contractions along the isolated whole human colon have now also been made. This review will highlight some of these advances and how impairments to these motility patterns may contribute to delayed colonic transit, known to exist in a proportion of patients with chronic constipation.

Changes in interstitial cells of cajal with age in the human stomach and colon

BACKGROUND

Aging produces inevitable changes in the function of most organs including the gastrointestinal tract. Together with enteric nerves and smooth muscle cells, interstitial cells of Cajal (ICC) play a key role in the control of gastrointestinal motility, yet little is known about the effect of aging on ICC. The aim of this study was to determine the effect of aging on ICC number and volume in the human stomach and colon.

METHODS

Gastric and colonic tissues from patients aged 25-70 and 36-92 years old, respectively, and with no co-existent motility disorders were immunolabeled with an anti-Kit antibody and ICC were counted in the circular muscle and myenteric regions. Network volumes were measured using 3D reconstructions of confocal stacks. The effects of aging were determined by testing for linear trends using regression analysis.

KEY RESULTS

In both stomach and colon, the number of ICC bodies and volume significantly decreased with age at a rate of 13% per decade. ICC size was only affected in the myenteric plexus in the colon. The changes associated with age were not differentially affected by sex or colonic region.

CONCLUSIONS & INFERENCES

The number and volume of ICC networks in the normal human stomach and colon decline with age. This decrease in ICC likely reduces the functional capacity of the gastrointestinal motor apparatus, may contribute to changes in gastrointestinal motility with aging and may influence intestinal responses to insults such as disease, operative interventions and medications in older patients. Tissue specimens must be carefully age-matched when studying ICC in disease.

Human intestinal microbiota and healthy ageing

Earlier studies have indicated a decrease in anaerobes and bifidobacteria and a concomitant increase in enterobacteria in the intestinal microbiota with ageing. However, new data obtained with molecular techniques suggests decreased stability and increased diversity of the gut microbiota with advancing age. Further, no simple marker change in microbiota composition can be identified. Except for the reduced immune function, ageing itself may have relatively little effect on overall gastrointestinal function. Concomitant changes in nutrition, increased incidence of disease and corresponding use of medication with advancing age modify the composition of the microbial community of the gastrointestinal tract. This mini-review will focus on the recent findings on the gut microbiota of the elderly and on the potential benefits of probiotics, prebiotics and synbiotics.

Diarrhea-predominant irritable bowel syndrome is associated with diverticular disease: a population-based study

OBJECTIVES

A subset of patients with colonic diverticular disease have chronic gastrointestinal symptoms, and some have a clinical diagnosis of irritable bowel syndrome (IBS), but whether IBS and diverticular disease are linked is uncertain. We aimed to evaluate this association in the community.

METHODS

A population-based, cross-sectional survey was conducted by mailing a valid symptom questionnaire to the eligible residents of Olmsted County, MN, aged 30-95 years. Colonic diverticular disease (diverticulosis and diverticulitis) was ascertained through a review of the complete medical history of all responders. Subjects with at least one relevant test (colonoscopy, computed tomography (CT) scan, CT colonography, or barium enema) were included. IBS was defined using Rome II criteria.

RESULTS

Among 2,267 eligible respondents, there were 1,712 subjects who had undergone colon testing (76%): 919 women (54%); mean (+/-s.d.) age 65 (+/-11 years). Colonic diverticular disease was identified in 44.4% (95% confidence interval (CI) 42.1-46.8) of the subject. IBS was reported by 8.8% (95% CI 6.9-11.0) of men and 17.0% (95% CI 14.6-19.6) of women. After adjusting for age and gender, the presence of IBS was associated with an increased odds for diverticulosis (odds ratio (OR) =1.8, 95% CI 1.3-2.4) but not diverticulitis (OR=1.7, 95% CI 0.9-3.2). In those 65 years of age or older, the presence of IBS was associated with a ninefold higher odds for diverticulosis (OR=9.4, 95% CI 5.8-15.1). Relative to the non-IBS subgroup, diarrhea-predominant IBS and mixed IBS were significantly associated with an increased odds for diverticular disease (OR=1.9, 95% CI 1.1-3.2; OR=2.6, 95% CI 1.0-6.4, respectively).

CONCLUSIONS

There is a significantly increased odds for colonic diverticulosis in subjects with IBS (relative to those without IBS). These results suggest that IBS and colonic diverticular disease may be connected.

Irritable bowel syndrome in the elderly: An overlooked problem?

BACKGROUND

In secondary care, irritable bowel syndrome (IBS) is frequently associated with non-colonic symptoms including lethargy, backache and chest pains which can result in inappropriate referral to different specialities with the condition remaining unrecognised. This could also be a problem in the elderly where comorbidity is common, especially as irritable bowel syndrome is usually associated with a younger age group.

METHODS

A survey of 230 consecutive patients (aged 65-94) attending an elderly care clinic examining referral patterns, irritable bowel syndrome symptoms, duration of disease, non-colonic symptomatology and previous investigation.

RESULTS

211 of 230 (92%) patients completed the questionnaire with 46 (22%) having symptoms suggestive of irritable bowel syndrome irrespective of presenting complaint. However despite the exclusion of abdominal pathology the diagnosis was only made in one patient. Symptoms significantly more common in irritable bowel syndrome than non-irritable bowel syndrome patients were constant lethargy (p<0.001), headaches (p=0.01), backache (p=0.02), chest pain (p=0.03), and urinary frequency (p=0.04). Independent predictors of irritable bowel syndrome on logistic regression were bloating (OR 13.3; p<0.001), stool urgency (OR 4.0; p<0.001) and headache (OR 2.3; p=0.01).

CONCLUSIONS

Irritable bowel syndrome is under-recognised in elderly care despite negative investigation. Making the diagnosis, even in the presence of co-existent disease, could reduce the overall burden of suffering, improve quality of life and prevent repetitive investigations.

Age-related changes in functional NANC innervation with VIP and substance P in the jejunum of Lewis rats

Age-related changes in non-adrenergic, non-cholinergic (NANC) neurotransmission might contribute to differences in gastrointestinal motility. Our aim was to determine age-related changes in functional innervation with vasoactive intestinal polypeptide (VIP) and substance P (Sub P) in rat jejunum. We hypothesized that maturation causes changes in neurotransmission with these two neuropeptides. Longitudinal and circular jejunal muscle strips from young (3 months) and middle-aged (15 months) rats (total: 24 rats) were studied; the response to exogenous VIP and Sub P and the effect of their endogenous release from the enteric nervous system during electrical field stimulation (EFS) were evaluated. In longitudinal muscle, response to exogenous VIP and endogenously released VIP during EFS were increased in middle-aged rats, while the effect of endogenously released Sub P was decreased. In the circular muscle, the response to endogenously released VIP was increased in middle-aged rats, while the effects of exogenous VIP and endogenously released Sub P were unchanged. Response to exogenous Sub P was unaffected by maturation in both muscle layers. Spontaneous contractile activity was increased in the longitudinal and circular muscle of the older rats. In the jejunum of middle-aged rats, participation of VIP in functional NANC innervation was increased, while functional innervation with Sub P was decreased. These changes in the balance of inhibitory and excitatory neurotransmission occur during the year of maturation in rats and demonstrate an age-dependant plasticity of neuromuscular bowel function.