Dietary habits and right-sided colonic diverticulosis

The Epidemiology and Etiology of Right-Sided Colonic Diverticulosis: A Review

Diverticulosis of the colon is a common condition in Western countries and most patients will remain asymptomatic, but some will present with symptoms of acute diverticulitis or bleeding. Our understanding of diverticulosis is evolving but is mostly derived from diverticulosis affecting the left-sided colon. In contrast, right-sided colonic diverticulosis (RCD) is more commonly seen in Asian countries but is much less common overall. Based on the marked differences in epidemiology, it is commonly thought that these are 2 distinct disease processes. A review of the literature describing the epidemiology and etiology of RCD was performed, with a comparison to the current understanding of left-sided diverticulosis. RCD is becoming increasingly common. The epidemiology of RCD shows it to be a mostly acquired condition, and not congenital as previously thought. Many factors in the etiology of RCD are similar to that seen in left-sided diverticulosis, with a few variations. It is therefore likely that most cases of RCD represent the same disease process that is seen in the left colon.

Diverticular Disease Epidemiology: Rising Rates of Diverticular Disease Mortality Across Developing Nations

BACKGROUND

The incidence of diverticular disease is growing in the Western world. However, the global burden of disease is unknown in the developing world.

OBJECTIVE

This study aimed to determine the global burden of diverticular disease as measured by disease-specific mortality while identifying indicators of rising disease rates.

DESIGN

We undertook an ecological analysis based on data from the World Health Organization Mortality Database. Then, we analyzed global age-adjusted mortality rates from diverticular disease and compared them to national rates of overweight adults, health expenditures, and dietary composition.

SETTINGS

National vital statistics data were collected.

PATIENTS

Diverticular disease deaths from January 1, 1994 through December 31, 2016 were evaluated.

MAIN OUTCOME MEASURES

The primary outcome measured was the national age-adjusted mortality rate.

RESULTS

The average age-adjusted mortality rate for diverticular disease was 0.51 ± 0.31/100,000 with a range of 0.11 to 1.75/100,000. During the study period, we noted that 57% of nations had increasing diverticular disease mortality rates, whereas only 7% had decreasing rates. More developed nations (40%) than developing nations (24%) were categorized as having high diverticular disease mortality burden over the time period of the study, and developed nations had higher percentages of overweight adults (58.9 ± 3.1%) than developing nations (50.6 ± 6.7%; p < 0.0001). However, developing nations revealed more rapid increases in diverticular disease mortality (0.027 ± 0.024/100,000 per year) than developed nations (0.005 ± 0.025/100,000 per year; p = 0.001), as well as faster expanding proportions of overweight adults (0.76 ± 0.12% per year) than in already developed nations (0.53 ± 0.10% per year; p<0.0001).

LIMITATIONS

Ecological studies cannot define cause and effect.

CONCLUSIONS

There is considerable variability in diverticular disease mortality across the globe. Developing nations were characterized by rapid increases in diverticular disease mortality and expanding percentages of overweight adults. Public health interventions in developing nations are needed to alter mortality rates from diverticular disease. See Video Abstract at http://links.lww.com/DCR/B397. EPIDEMIOLOGÍA DE LA ENFERMEDAD DIVERTICULAR: TASAS CRECIENTES DE MORTALIDAD POR ENFERMEDAD DIVERTICULAR EN LOS PAÍSES EN DESARROLLO: La incidencia de la enfermedad diverticular está creciendo en el mundo occidental. Sin embargo, la carga mundial de la enfermedad es desconocida en el mundo en desarrollo.Determinar la carga global de la enfermedad diverticular medida por la mortalidad específica de la enfermedad mientras se identifican los indicadores de aumento de las tasas de enfermedad.Realizamos un análisis ecológico basado en datos de la Base de datos de mortalidad de la Organización Mundial de la Salud. Luego, analizamos las tasas globales de mortalidad ajustadas por edad por enfermedad diverticular y las comparamos con las tasas nacionales de adultos con sobrepeso, gastos de salud y composición dietética.Datos nacionales de estadísticas vitales.Muertes por enfermedades diverticulares desde el 1 de enero de 1994 hasta el 31 de diciembre de 2016.Tasa nacional de mortalidad ajustada por edad.La tasa promedio de mortalidad ajustada por edad para la enfermedad diverticular fue de 0,51 ± 0,31 / 100,000 con un rango de 0,11 a 1,75 / 100,000. Durante el período de estudio, notamos que el 57% de las naciones tenían tasas crecientes de mortalidad por enfermedades diverticulares, mientras que solo el 7% tenían tasas decrecientes. Las naciones más desarrolladas (40%) que las naciones en desarrollo (24%) se clasificaron como que tienen una alta carga de mortalidad por enfermedad diverticular durante el período de tiempo del estudio, y las naciones desarrolladas tuvieron porcentajes más altos de adultos con sobrepeso (58.9 ± 3.1%) que las naciones en desarrollo (50,6 ± 6,7%) (p <0,0001). Sin embargo, las naciones en desarrollo revelaron aumentos más rápidos en la mortalidad por enfermedades diverticulares (0.027 ± 0.024 / 100,000 por año) que las naciones desarrolladas (0.005 ± 0.025 / 100,000 por año) (p = 0.001), así como proporciones de adultos con sobrepeso en expansión más rápida (0.76 ± 0.12% por año) que en las naciones ya desarrolladas (0.53 ± 0.10% por año) (p <0.0001).Los estudios ecológicos no pueden definir causa y efecto.Existe una considerable variabilidad en la mortalidad por enfermedad diverticular en todo el mundo. Los países en desarrollo se caracterizaron por un rápido aumento en la mortalidad por enfermedades diverticulares y porcentajes crecientes de adultos con sobrepeso. Se necesitan intervenciones de salud pública en los países en desarrollo para alterar las tasas de mortalidad por enfermedad diverticular. Consulte Video Resumen en http://links.lww.com/DCR/B397.

Dietary pattern and its association with right-colonic diverticulosis

BACKGROUND AND AIM

In East Asia, colonic diverticulosis develops most commonly in the right colon and is known to have different characteristics compared with left-sided one. This study was designed to investigate whether right-colonic diverticulosis is associated with posteriori dietary patterns.

METHODS

We retrospectively reviewed medical records of prospectively collected cohort that received health check-up in Korea between May 2011 and January 2012. Their anthropometric data, biochemical results, medication history, underlying diseases, colonoscopic findings, and dietary data obtained from semi-quantitative food-frequency questionnaire were analyzed. Three dietary patterns were identified using factor analysis: healthy dietary pattern (vegetables, fish, seaweed, fruits, and beans), meat dietary pattern (red meat, processed meat/fish, fried noodle, poultry, and cephalopods), and snack dietary pattern (bread, sweets, dairy products, nuts, and rice cake).

RESULTS

Out of the total 1911 patients, 203 (10.6%) had right-colonic diverticulosis, 21 (1.1%) had pan-colonic diverticulosis, and 12 (0.6%) had left-colonic diverticulosis. Among the total, none of the three patterns were associated with right-colonic diverticulosis, under adjustment with age, gender, body mass index, metabolic syndrome, and total energy intake. However, among women, meat dietary pattern was positively associated with right-colonic diverticulosis (odds ratio 1.866, 95% confidence interval: 1.0983-3.173, P = 0.021).

CONCLUSION

This study demonstrated that meat dietary pattern is positively associated with right-colonic diverticulosis among women.

Fruit and vegetable consumption is associated with lower prevalence of asymptomatic diverticulosis: a cross-sectional colonoscopy-based study

Background

Previous studies of the relationship between dietary factors and risk of diverticulosis have yielded inconsistent results. We therefore sought to investigate the association between consumption of fruit and vegetables and prevalent diverticulosis.

Methods

Our study population included participants in the Gastrointestinal Disease and Endoscopy Registry (GIDER), a colonoscopy-based longitudinal cohort at the Massachusetts General Hospital, who provided comprehensive information on dietary intake and lifestyle factors using validated questionnaires prior to colonoscopy. Information on presence and location of diverticula was obtained from the endoscopist at the end of each procedure. We used Poisson regression modeling to calculate the prevalence ratios (PRs) and 95% confidence intervals (CIs).

Results

Among 549 participants with a mean age of 61 years enrolled in GIDER, we confirmed diverticulosis in 245 (44.6%). The prevalence of diverticulosis appeared to decrease with higher consumption of fruit and vegetables (P_trend = 0.007 for fruit and 0.008 for vegetables, respectively). Compared to participants with less than five servings of vegetables per week, the multivariable-adjusted PRs of diverticulosis were 0.84 (95% CI, 0.60–1.17) with five to seven servings per week and 0.62 (95% CI, 0.44–0.89) with greater than one serving per day. Similarly, compared to participants with less than five servings per week of fruit, the multivariable-adjusted PR of diverticulosis was 0.60 (95% CI, 0.41–0.87) with greater than one serving per day. These associations were not modified by age, BMI, smoking, or red meat intake (All P_interaction > 0.055).

Conclusion

In a colonoscopy-based longitudinal cohort study, we show that higher consumption of fruit and vegetables is associated with lower risk of prevalent diverticulosis.

Intake of Dietary Fiber, Fruits, and Vegetables and Risk of Diverticulitis

OBJECTIVES

Although low fiber intake has been considered a risk factor for diverticulitis, prospective evidence is limited in women despite having a disproportionate burden of disease, with little known about variation in the protective effects according to food sources. We assessed the associations of intakes of fiber and major food sources of fiber including fruits and vegetables with risk of diverticulitis in a large cohort of women.

METHODS

We followed 50,019 women in the Nurses' Health Study (1990-2014) who were aged 43-70 years and free of diverticulitis, cancer, and inflammatory bowel disease at baseline. Incident diverticulitis was identified through self-report with validity confirmed by review of medical records.

RESULTS

We documented 4,343 incident cases of diverticulitis, encompassing 1,106,402 person-years of follow-up. Compared with participants in the lowest quintile, the multivariable hazard ratio of diverticulitis in the highest quintile of total fiber intake was 0.86 (95% confidence interval: 0.78-0.95; P-trend = 0.002). Fiber from fruits and cereals, but not vegetables, was associated with a decreased risk of diverticulitis. Furthermore, intake of total whole fruit intake and specific fruits such as apples/pears and prunes were associated with reduced risk of diverticulitis with a multivariable hazard ratio for diverticulitis of 0.95 (0.92-0.98; P-trend < 0.001) for every serving increase of total whole fruit intake per day.

DISCUSSION

Higher intake of dietary fiber and fiber from different food sources, except for vegetable fiber, are associated with a lower risk of diverticulitis in women. A greater intake of whole fruit is also associated with reduced risk.

Progress and challenges in the management of diverticular disease: which treatment?

Diverticular disease of the colon (DDC) includes a spectrum of conditions from asymptomatic diverticulosis to symptomatic uncomplicated diverticulosis, segmental colitis associated with diverticulosis, and acute diverticulitis without or with complications that may have serious consequences. Clinical and scientific interest in DDC is increasing because of the rising incidence of all conditions within the DDC spectrum, a better, although still limited understanding of the pathogenic mechanisms involved; the increasing socioeconomic burden; and the new therapeutic options being tested. The goals of treatment in DDC are symptom and inflammation relief and preventing disease progression or recurrence. The basis for preventing disease progression remains a high-fiber diet and physical exercise, although evidence is poor. Other current strategies do not meet expectations or lack a solid mechanistic foundation; these strategies include modulation of gut microbiota or dysbiosis with rifaximin or probiotics, or using mesalazine for low-grade inflammation in uncomplicated symptomatic diverticulosis. Most acute diverticulitis is uncomplicated, and the trend is to avoid hospitalization and unnecessary antibiotic therapy, but patients with comorbidities, sepsis, or immunodeficiency should receive broad spectrum and appropriate antibiotics. Complicated acute diverticulitis may require interventional radiology or surgery, although the best surgical approach (open versus laparoscopic) remains a matter of discussion. Prevention of acute diverticulitis recurrence remains undefined, as do therapeutic strategies. Mesalazine with or without probiotics has failed to prevent diverticulitis recurrence, whereas new studies are needed to validate preliminary positive results with rifaximin. Surgery is another option, but the number of acute events cannot guide this indication. We need to identify risk factors and disease progression or recurrence mechanisms to implement appropriate preventive strategies.

Epidemiology and Pathophysiology of Diverticular Disease

Colonic diverticular disease is a common health care issue which has historically been attributed to western countries and older age population. Recent studies have shown a rise in incidence among developing countries that have adopted western diets as well as rise in prevalence among younger patients. In this article, the authors discuss the incidence, epidemiology, and pathophysiology of colonic diverticular disease.

Higher Mortality in Surgically Managed Diverticulitis is Associated with Asian Ethnicity and Right-Sided Disease

BACKGROUND

Although right-sided diverticulitis is perceived to have a higher incidence among Asians and infrequently requires surgical management in comparison with sigmoid diverticulitis, it is unknown whether differences in outcomes are due to ethnic disparity or disease pathophysiology.

OBJECTIVE

The aim of this study was to determine the surgical outcomes for Asian and non-Asian patients with diverticulitis who underwent colectomy.

DESIGN

Patients identifiable by ethnicity in the Nationwide Inpatient Sample with diverticulitis and colectomy between 2004 and 2010 were included. Univariate comparisons were made between Asian and non-Asian patients by using t tests for continuous variables and χ tests for categorical variables. Propensity score matching analysis was performed to compare Asian patients with otherwise similar non-Asian patients.

PATIENTS

Included were 58,142 non-Asian and 335 Asian patients with diverticulitis who underwent a colectomy.

MAIN OUTCOME MEASURES

The primary outcomes were in-hospital mortality, hospital length of stay, and total costs.

RESULTS

Asian patients were younger (56.1 vs. 59.2 years, p < 0.0001), were more likely to undergo a right colectomy (22.7% vs. 4.1%, p < 0.0001), and were more likely to have emergent/urgent surgery than the non-Asian patients (67.1% vs. 49.8%, p < 0.0001). Without controlling for patient/disease factors, there were statistically significant differences in mortality (non-Asian 2.2% vs. Asian 4.2%; p = 0.014), length of stay (non-Asian 8.9 vs. Asian 9.8 days; p = 0.0166), and costs (non-Asian $18,783 vs. Asian $21,901; p = 0.001). Propensity score matching comparing 333 non-Asian patients with 333 similar Asian patients showed that, whereas differences in cost and length of stay became insignificant, the difference in mortality remained statistically significant.

LIMITATIONS

The ethnicity variable was not uniformly collected by all states within the Nationwide Inpatient Sample database.

CONCLUSIONS

Among patients undergoing a colectomy for diverticulitis, a higher mortality was observed in Asian patients and right-sided disease. Future longitudinal studies comparing the natural history and outcomes of management between right- and left-sided diverticulitis are necessary to investigate whether a true ethnic disparity exists.

The genetic epidemiology of diverticulosis and diverticular disease: Emerging evidence

Diverticular disease (DD) is one of the most prevalent gastrointestinal disorders. The pathogenesis of diverticulosis and DD is controversially discussed. Current studies call the traditional concept of a fibre-deficient diet causing the development of diverticula into question. Data from two recent twin studies have provided conclusive evidence for a strong genetic component to diverticulosis. Although genomewide association studies have provided new insights into the polygenic architecture of human diseases, genomic research in diverticulosis and DD has just been started. This is an astonishing fact given the high morbidity and mortality of the disease, as well as the substantial economic burden on health care systems. For this review, we provide an update of the molecular pathobiology and summarise recent evidence supporting the hypothesis that distinct, yet unidentified genetic variants contribute to the development of diverticulosis and DD.

Management of diverticular disease

Diverticular disease is a common condition in Western countries and the incidence and prevalence of the disease is increasing. The pathogenetic factors involved include structural changes in the gut that increase with age, a diet low in fibre and rich in meat, changes in intestinal motility, the concept of enteric neuropathy and an underlying genetic background. Current treatment strategies are hampered by insufficient options to stratify patients according to individual risk. One of the main reasons is the lack of an all-encompassing classification system of diverticular disease. In response, the German Society for Gastroenterology and Digestive Diseases (DGVS) has proposed a classification system as part of its new guideline for the diagnosis and management of diverticular disease. The classification system includes five main types of disease: asymptomatic diverticulosis, acute uncomplicated and complicated diverticulitis, as well as chronic diverticular disease and diverticular bleeding. Here, we review prevention and treatment strategies stratified by these five main types of disease, from prevention of the first attack of diverticulitis to the management of chronic complications and diverticular bleeding.

Risk Factors for Diverticulosis, Diverticulitis, Diverticular Perforation, and Bleeding: A Plea for More Subtle History Taking

Background

Diverticulosis is a very common condition. Around 20% of diverticula carriers are believed to suffer from diverticular disease during their lifetime. This makes diverticular disease one of the clinically and economically most significant conditions in gastroenterology. The etiopathogenesis of diverticulosis and diverticular disease is not well understood. Epidemiological studies allowed to define risk factors for the development of diverticulosis and the different disease entities associated with it, in particular diverticulitis, perforation, and diverticular bleeding.

Methods

A comprehensive literature search was performed, and the current knowledge about risk factors for diverticulosis and associated conditions reviewed.

Results

Non-controllable risk factors like age, sex, and genetics, and controllable risk factors like foods, drinks, and physical activity were identified, as well as comorbidities and drugs which increase or decrease the risk of developing diverticula or of suffering from complications. In naming risk factors, it is of utmost importance to differentiate between diverticulosis and the different disease entities.

Conclusion

Risk factors for diverticulosis and diverticular disease may give a clue towards the possible etiopathogenesis of the conditions. More importantly, knowledge of comorbidities and particularly drugs conferring a risk for development of complicated disease is crucial for patient management.

Risk factors for recurrence of right colonic uncomplicated diverticulitis after first attack

PURPOSE

Most patients with acute right colonic uncomplicated diverticulitis can be managed conservatively. The aim of this study was to assess the clinical and radiologic risk factors for recurrence in patients with right colonic uncomplicated diverticulitis.

METHODS

The present survey included 469 patients who were successfully managed conservatively for the first episode of right colonic uncomplicated diverticulitis between 2002 and 2012 in a referral center, and records were reviewed from collected data. Patients were divided into two groups: a nonrecurrent and a recurrent group. The clinical and radiologic features of all patients were analyzed to identify possible risk factors for recurrence. The Kaplan-Meier method and Cox regression were used.

RESULTS

Seventy-four (15.8 %) patients had recurrence, and 15 (3.2 %) received surgery at recurrence within a median follow-up of 59 months. The mean recurrence interval after the first attack was 29 months. In univariate and multivariate analyses, risk factors for recurrence were confirmed multiple diverticula (relative risk [RR], 2.62; 95 % confidence interval [CI], 1.56-4.40) and intraperitoneally located diverticulitis (RR, 3.73; 95 % CI, 2.13-6.52). Of 66 patients with two risk factors, 36 (54.5 %) had recurrence and 10 (15.2 %) received surgery at recurrence.

CONCLUSIONS

In patients with right colonic uncomplicated diverticulitis who have multiple diverticula and intraperitoneally located diverticulitis, the possibility of recurrence and surgical rate are high. Poor outcome may be cautioned in these patients.

Source of dietary fibre and diverticular disease incidence: a prospective study of UK women

BACKGROUND

Previous prospective studies have found the incidence of intestinal diverticular disease decreased with increasing intakes of dietary fibre, but associations by the fibre source are less well characterised. We assessed these associations in a large UK prospective study of middle-aged women.

METHODS AND FINDINGS

During 6 (SD 1) years follow-up of 690 075 women without known diverticular disease who had not changed their diet in the last 5 years, 17 325 were admitted to hospital or died with diverticular disease. Dietary fibre intake was assessed using a validated 40-item food questionnaire and remeasured 1 year later in 4265 randomly-selected women. Mean total dietary fibre intake at baseline was 13.8 (SD 5.0) g/day, of which 42% came from cereals, 22% from fruits, 19% from vegetables (not potatoes) and 15% from potatoes. The relative risk (95% CI) for diverticular disease per 5 g/day fibre intake was 0.86 (0.84 to 0.88). There was significant heterogeneity by the four main sources of fibre (p<0.0001), with relative risks, adjusted for each of the other sources of dietary fibre of 0.84 (0.81 to 0.88) per 5 g/day for cereal, 0.81 (0.77 to 0.86) per 5 g/day for fruit, 1.03 (0.93 to 1.14) per 5 g/day for vegetable and 1.04 (1.02 to 1.07) per 1 g/day for potato fibre.

CONCLUSIONS

A higher intake of dietary fibre is associated with a reduced risk of diverticular disease. The associations with diverticular disease appear to vary by fibre source, and the reasons for this variation are unclear.

Diverticular disease: reconsidering conventional wisdom

Colonic diverticula are common in developed countries and complications of colonic diverticulosis are responsible for a significant burden of disease. Several recent publications have called into question long-held beliefs about diverticular disease. Contrary to conventional wisdom, studies have not shown that a high-fiber diet protects against asymptomatic diverticulosis. The risk of developing diverticulitis among individuals with diverticulosis is lower than the 10% to 25% proportion that commonly is quoted, and may be as low as 1% over 11 years. Nuts and seeds do not increase the risk of diverticulitis or diverticular bleeding. It is unclear whether diverticulosis, absent diverticulitis, or overt colitis is responsible for chronic gastrointestinal symptoms or worse quality of life. The role of antibiotics in acute diverticulitis has been challenged by a large randomized trial that showed no benefit in selected patients. The decision to perform elective surgery should be made on a case-by-case basis and not routinely after a second episode of diverticulitis, when there has been a complication, or in young people. A colonoscopy should be performed to exclude colon cancer after an attack of acute diverticulitis but may not alter outcomes among individuals who have had a colonoscopy before the attack. Given these surprising findings, it is time to reconsider conventional wisdom about diverticular disease.

Constipation and a low-fiber diet are not associated with diverticulosis

BACKGROUND & AIMS

Asymptomatic diverticulosis is commonly attributed to constipation caused by a low-fiber diet, although evidence for this mechanism is limited. We examined the associations between constipation and low dietary fiber intake with risk of asymptomatic diverticulosis.

METHODS

We performed a cross-sectional study that analyzed data from 539 individuals with diverticulosis and 1569 without (controls). Participants underwent colonoscopy and assessment of diet, physical activity, and bowel habits. Our analysis was limited to participants with no knowledge of their diverticular disease to reduce the risk of biased responses.

RESULTS

Constipation was not associated with an increased risk of diverticulosis. Participants with less frequent bowel movements (<7/wk) had reduced odds of diverticulosis compared with those with regular bowel movements (7/wk) (odds ratio [OR], 0.56; 95% confidence interval [CI], 0.40-0.80). Those reporting hard stools also had reduced odds (OR, 0.75; 95% CI, 0.55-1.02). There was no association between diverticulosis and straining (OR, 0.85; 95% CI, 0.59-1.22) or incomplete bowel movement (OR, 0.85; 95% CI, 0.61-1.20). We found no association between dietary fiber intake and diverticulosis (OR, 0.96; 95% CI, 0.71-1.30) in comparing the highest quartile with the lowest (mean intake, 25 vs 8 g/day).

CONCLUSIONS

In our cross-sectional, colonoscopy-based study, neither constipation nor a low-fiber diet was associated with an increased risk of diverticulosis.

Alcohol consumption is a risk factor for colonic diverticulosis

BACKGROUND AND AIM

The exact factors predisposing to colonic diverticulosis other than age are unknown.

METHODS

Cross-sectional study of asymptomatic subjects undergoing screening colonoscopy. A detailed dietary and social questionnaire was completed on all participants. A worldwide review of the literature was performed to further investigate any association between identified risk factors and diverticulosis.

RESULTS

Seven hundred forty-six consecutive individuals were enrolled (mean age, 61.1±8.3 y; female: male=0.98). Overall, the prevalence of diverticulosis was 32.8% (95% CI, 29.5-36.2). Diverticula were left-sided, right-sided, or both in 71.5%, 5.8%, and 22.7% of affected subjects, respectively. On univariate analysis, age, sex, adenomatous polyps, advanced neoplasia (adenoma≥1 cm, villous histology, or cancer), aspirin, and alcohol use were significantly associated with diverticulosis. Diet, body mass index, physical activity, and bowel habits were not associated with the disease. On multivariate analysis, increasing age (P<0.001), advanced neoplasia (P=0.021), and alcohol consumption (P<0.001) were significantly associated with diverticulosis. The adjusted odds ratio for diverticulosis in alcohol users was 1.91 (1.36 to 2.69), with increasing prevalence with higher alcohol consumption (P-value for trend=0.001). When the prevalence of diverticulosis reported from 18 countries was analyzed against alcohol use, there was a strong correlation with national per-capita alcohol consumption rates (Pearson correlation coefficient r=0.68; P=0.002).

CONCLUSIONS

Alcohol use is a significant risk factor for colonic diverticulosis and may offer a partial explanation for the existing East-West paradox in disease prevalence and phenotype. Further studies are needed to investigate this association and its putative pathophysiological mechanisms.

Coexistent widespread small intestinal and colonic diverticular disease

A 73-year-old woman with a history of multiple abdominal surgery and sigmoid diverticulosis presented with severe constipation refractory to conservative management. As a result, she had developed food aversion and cachexia. Patient opted for laparotomy and defunctioning ileostomy to improve quality of life. At laparotomy, extensive diverticulae involving the small and large bowels were identified. Defunctioning ileostomy was performed. The patient regained her quality of life and reinstituted normal diet. Histology revealed marked serosal fibrosis and pulsion diverticulae.

Diverticular disease as a chronic illness: evolving epidemiologic and clinical insights

Diverticular disease imposes a significant burden on Western and industrialized societies. The traditional pathogenesis model posits that low dietary fiber predisposes to diverticulosis, and fecalith obstruction prompts acute diverticulitis that is managed with broad-spectrum antibiotics or surgery. However, a growing body of knowledge is shifting the paradigm of diverticular disease from an acute surgical illness to a chronic bowel disorder composed of recurrent abdominal symptoms and considerable psychosocial impact. New research implicates a role for low-grade inflammation, sensory-motor nerve damage, and dysbiosis in a clinical picture that mimics irritable bowel syndrome (IBS) and even inflammatory bowel disease (IBD). Far from being an isolated event, acute diverticulitis may be the catalyst for chronic symptoms including abdominal pain, cramping, bloating, diarrhea, constipation, and "post-diverticulitis IBS." In addition, studies reveal lower health-related quality of life in patients with chronic diverticular disease vs. controls. Health-care providers should maintain a high index of suspicion for the multifaceted presentations of diverticular disease, and remain aware that it might contribute to long-term emotional distress beyond traditional diverticulitis attacks. These developments are prompting a shift in therapeutic approaches from widespread antimicrobials and supportive care to the use of probiotics, mesalamine, and gut-directed antibiotics. This review addresses the emerging literature regarding epidemiology, pathophysiology, and management of chronic, symptomatic diverticular disease, and provides current answers to common clinical questions.

Diet and risk of diverticular disease in Oxford cohort of European Prospective Investigation into Cancer and Nutrition (EPIC): prospective study of British vegetarians and non-vegetarians

OBJECTIVE

To examine the associations of a vegetarian diet and dietary fibre intake with risk of diverticular disease.

DESIGN

Prospective cohort study.

SETTING

The EPIC-Oxford study, a cohort of mainly health conscious participants recruited from around the United Kingdom.

PARTICIPANTS

47,033 men and women living in England or Scotland of whom 15,459 (33%) reported consuming a vegetarian diet.

MAIN OUTCOME MEASURES

Diet group was assessed at baseline; intake of dietary fibre was estimated from a 130 item validated food frequency questionnaire. Cases of diverticular disease were identified through linkage with hospital records and death certificates. Hazard ratios and 95% confidence intervals for the risk of diverticular disease by diet group and fifths of intake of dietary fibre were estimated with multivariate Cox proportional hazards regression models.

RESULTS

After a mean follow-up time of 11.6 years, there were 812 cases of diverticular disease (806 admissions to hospital and six deaths). After adjustment for confounding variables, vegetarians had a 31% lower risk (relative risk 0.69, 95% confidence interval 0.55 to 0.86) of diverticular disease compared with meat eaters. The cumulative probability of admission to hospital or death from diverticular disease between the ages of 50 and 70 for meat eaters was 4.4% compared with 3.0% for vegetarians. There was also an inverse association with dietary fibre intake; participants in the highest fifth (≥25.5 g/day for women and ≥26.1 g/day for men) had a 41% lower risk (0.59, 0.46 to 0.78; P<0.001 trend) compared with those in the lowest fifth (<14 g/day for both women and men). After mutual adjustment, both a vegetarian diet and a higher intake of fibre were significantly associated with a lower risk of diverticular disease.

CONCLUSIONS

Consuming a vegetarian diet and a high intake of dietary fibre were both associated with a lower risk of admission to hospital or death from diverticular disease.

Demographic determinants of risk, colon distribution and density scores of diverticular disease

AIM: To investigate associations between ethnicity, age and sex and the risk, colon distribution and density scores of diverticular disease (DD).

METHODS: Barium enemas were examined in 1000 patients: 410 male, 590 female; 760 whites, 62 Asians, 44 black africans (BAs), and 134 other blacks (OBs). Risks and diverticula density of left-sided DD (LSDD) and right-sided-component DD (RSCDD = right-sided DD + right and left DD + Pan-DD) were compared using logistic regression.

RESULTS: Four hundred and forty-seven patients had DD (322 LSDD and 125 RSCDD). Adjusted risks: (1) LSDD: each year increase in age increased the odds by 6% (95% CI: 5-8, SE: 0.8%, P < 0.001); Asians: odds ratio (OR): 0.23 (95% CI: 0.10-0.53, SE: 0.1, P≤ 0.001) and OBs: OR: 0.25 (95% CI: 0.14-0.43, SE: 0.07, P≤ 0.001) appeared protected vs Whites; (2) RSCDD: each year increase in age increased the odds by 4% (95% CI: 2-6, SE: 1%, P < 0.001); females were 0.60 times (95% CI: 0.40-0.90, SE: 0.12, P = 0.01) less likely than males to have RSCDD; BAs were 3.51 times (95% CI: 1.70-7.24, SE: 1.30, P < 0.001) more likely than Whites to have RSCDD; and (3) DD density scores: each year increase in age increased the odds of high-density scores by 4% (95% CI: 1-6, SE: 1%, P < 0.001); RSCDD was 2.77 times (95% CI: 1.39-3.32, SE: 0.67, P < 0.001) more likely to be of high density than LSDD. No further significant differences were found in the adjusted models.

CONCLUSION: Right colonic DD might be more common and has higher diverticula density in the west than previously reported. BAs appear predisposed to DD, whereas other ethnic differences appear conserved following migration.

Review article: the current and evolving treatment of colonic diverticular disease

BACKGROUND

Formation of colonic diverticula, via herniation of the colonic wall, is responsible for the development of diverticulosis and consequently diverticular disease. Diverticular disease can be associated with numerous debilitating abdominal and gastrointestinal symptoms (including pain, bloating, nausea, constipation and diarrhoea).

AIMS

To review the state of treatment for diverticular disease and its complications, and briefly discuss potential future therapies.

METHODS

PubMed and recent conference abstracts were searched for articles describing the treatment of diverticular disease.

RESULTS

Many physicians will recommend alterations to lifestyle and increasing fibre consumption. Empirical antibiotics remain the mainstay of therapy for patients with diverticular disease and rifaximin seems to be the best choice. In severe or relapsing disease, surgical intervention is often the only remaining treatment option. Although novel treatment options are yet to become available, the addition of therapies based on mesalazine (mesalamine) and probiotics may enhance treatment efficacy.

CONCLUSIONS

Data suggest that diverticular disease may share many of the hallmarks of other, better-characterized inflammatory bowel diseases; however, treatment options for patients with diverticular disease are scarce, revolving around antibiotic treatment and surgery. There is a need for a better understanding of the fundamental mechanisms of diverticular disease to design treatment regimens accordingly.

Diet, ageing and genetic factors in the pathogenesis of diverticular disease

Diverticular disease (DD) is an age-related disorder of the large bowel which may affect half of the population over the age of 65 in the UK. This high prevalence ranks it as one of the most common bowel disorders in western nations. The majority of patients remain asymptomatic but there are associated life-threatening co-morbidities, which, given the large numbers of people with DD, translates into a considerable number of deaths per annum. Despite this public health burden, relatively little seems to be known about either the mechanisms of development or causality. In the 1970s, a model of DD formulated the concept that diverticula occur as a consequence of pressure-induced damage to the colon wall amongst those with a low intake of dietary fiber. In this review, we have examined the evidence regarding the influence of ageing, diet, inflammation and genetics on DD development. We argue that the evidence supporting the barotrauma hypothesis is largely anecdotal. We have also identified several gaps in the knowledge base which need to be filled before we can complete a model for the etiology of diverticular disease.

Distribution of colon neoplasia in Chinese patients: implications for endoscopic screening strategies

OBJECTIVES

Our aim was to measure the prevalence and distribution of colonic neoplasia in Chinese adults, and to estimate the sensitivity of sigmoidoscopic screening strategies for detecting those with advanced neoplasia.

METHODS

Asymptomatic, average-risk Chinese adults aged 50 years or older underwent screening colonoscopy. The prevalence and distribution of colonic neoplasia and advanced neoplasia (defined as an adenoma >or=10 mm or with villous, high-grade dysplastic, or malignant features) were reviewed retrospectively and the outcomes of various sigmoidoscopic screening strategies estimated.

RESULTS

Of 1,382 individuals (833 men, 549 women; mean age 58.8 years) included, 243 (18%) had colorectal neoplasia and 72 (5.2%) had advanced neoplasia. Neoplasia prevalence was significantly higher in male and older patients. No significant differences were observed in neoplasia distribution between men and women. Overall, 24 patients had advanced neoplasia in the proximal colon, of whom four had synchronous distal neoplasia. The estimated sensitivity for detecting patients with advanced neoplasia was 72% if we assumed screening sigmoidoscopy was performed, with follow-up colonoscopy for those with distal neoplasia; 165 patients would need to undergo colonoscopy. If, instead, we assumed follow-up colonoscopy was done only for patients with distal advanced neoplasia, the estimated sensitivity would decrease slightly to 71%, but the number of colonoscopies would decrease substantially to 51.

CONCLUSION

In average-risk Chinese adults, screening sigmoidoscopy is estimated to detect more than two-thirds of patients with advanced neoplasia. In Chinese societies with limited health-care resources, performing colonoscopy only on patients with distal advanced neoplasia is a screening approach that optimizes the return rate on colonoscopic capacity.

Longitudinal muscle shows abnormal relaxation responses to nitric oxide and contains altered levels of NOS1 and elastin in uncomplicated diverticular disease

OBJECTIVE

Recent evidence challenges the 'low-fibre/high-colonic intraluminal pressure' hypothesis of diverticular disease (DD) and raises the possibility that other mechanisms are involved. Although bowel wall smooth muscle is known to be hypercontractile in DD, the nature of its relaxation is unknown. The present study investigated colonic smooth muscle responses to nitric oxide, as well as the smooth muscle contents of neural nitric oxide and elastin associated with the disease.

METHOD

Immunohistochemical/image analysis of antibodies to nitric oxide synthase (NOS1), co-localized with protein gene product (PGP) and to elastin, was performed on three histological sections of sigmoid colons from 20 patients (10 DD, 10 controls) following resections for rectal tumours. Organ bath experiments examined smooth muscle responsiveness to nitroprusside, a nitric oxide donor.

RESULTS

Uncomplicated diverticular longitudinal muscle showed lower nitric oxide immunoreactivity compared with controls: median percentage surface area of NOS1 over PGP was 26.0% (range 0.5-58.3), controls 45.0% (35.0-70.1; P = 0.018). Median percentage surface area of elastin was elevated, 21.3% (10.6-45.6), controls 8.2% (1.7-13.5; P = 0.0002), together with a low sensitivity to nitroprusside [mean - log EC(50) 5.3 (SD 0.5), controls 6.6 (SD 0.5), difference 1.3, 95% CI 0.8-1.7; P < 0.0001] and there were lower maximum relaxation responses to nitroprusside compared with controls: median percentage (relaxation induced by nitroprussside/contraction induced by bethanecol) was 52.0%, range (20.0-92.0), controls 100.0% (71.0-125.0), P < 0.0001. No statistically significant differences were found in circular muscle, at the sample size studied.

CONCLUSION

This study established, for the first time, specific abnormalities in longitudinal muscle relaxation and contents of neural nitric oxide and elastin in uncomplicated DD. These findings may have important implications for both colon structure and function in the disease.

Diverticular Disease in Patients with Colon Cancer: Subgroup Analysis of National Surgical Adjuvant Breast and Bowel Project Protocol C-06

BACKGROUND

Similar epidemiologic characteristics suggest a common etiology for colon cancer (CC) and diverticular disease of the colon (DD). The relationship between the 2 diseases is still unclear, and the impact of DD in patients diagnosed with CC on disease-free survival (DFS) and overall survival (OS) is unknown. National Surgical Adjuvant Breast and Bowel Project (NASBP) protocol C-06 is a clinical trial comparing oral uracil/tegafur/leucovorin with 5-fluorouracil/leucovorin in patients with resected stage II/III carcinoma of the colon.

PATIENTS AND METHODS

The NASBP enrolled 1,608 patients who had undergone potentially curative resection for stage II/III colon cancer from 256 medical sites between February 14, 1997, and March 31, 1999.

RESULTS

Pathology reports from 1561 eligible patients retrospectively reviewed for the presence of DD revealed that 160 (10.2%) had this disease. The median ages of patients with CC and DD and without DD were 67 and 61 years, respectively (P < 0.05). The majority of patients were white, and Hispanic patients were better represented in the group with DD (P < 0.05). Colon cancer was located in the rectosigmoid in 46.88% of patients with DD and in 31.92% of patients without DD (P < 0.05). A baseline diagnosis of DD made no significant contribution to DFS or OS without adjustment for confoundin factors (P = 0.2 and P = 0.32, respectively) or adjusted for Dukes classification and age (P = 0.49 and P = 0.68, respectively).

CONCLUSION

The prevalence of DD in patients diagnosed and treated for CC was 10.2%. Patients with CC with and without DD differed from each other with respect to age, tumor location, and ethnicity. There was no negative impact of having DD on DFS and OS in patients treated for stage II/III CC.

Diverticular disease of the colon: ethnic differences in frequency

BACKGROUND

Colonic diverticular disease is more common in Western populations than in developing countries.

AIM

To determine whether the frequency of colonic diverticular disease is different in British patients of Indian-subcontinent Asian origin compared with other ethnic groups.

METHODS

All colonoscopies performed over a 3-year period in a London hospital were studied. Patients of Indian-subcontinent Asian origin were identified by name.

RESULTS

Five of 134 Indian-subcontinent Asian males (4%) had colonic diverticular disease, compared with 278 of 1268 patients of other ethnic groups (22%; P < 0.001). Five of 91 Indian-subcontinent Asian females (6%) had colonic diverticular disease, compared with 333 of 1486 patients of other ethnic groups (23%; P < 0.001). Although patients of Indian-subcontinent Asian origin (54.8 +/- 15.8 years) were younger than those of other ethnic groups (60.3 +/- 17.8 years; P < 0.0001), the ethnic difference in the frequency of diverticular disease persisted even when age was taken into account.

CONCLUSION

There is a lower frequency of colonic diverticular disease in Indian-subcontinent Asians presenting for colonoscopy, compared with other ethnic groups. This cannot be explained by sex or age differences. Our findings require confirmation, but may provide opportunities for research into the aetiology of colonic diverticular disease.

Pathophysiological aspects of diverticular disease of colon and role of large bowel motility

Colonic diverticular disease (diverticulosis) is one of the most common gastrointestinal disorders in Western countries. This disorder is strictly related to aging and fibre intake, and still bears a discrete amount of morbidity. Numerous etiological co-factors have to date been implicated in the pathogenesis of the disease, yet the supporting evidence is still far from absolute. The present review considers the pathophysiology of colonic diverticular disease, with a special emphasis on factors related to abnormal colonic motility.

Pathophysiology of diverticular disease

There is substantial evidence that colonic diverticulosis is related to civilization, industrialization and a "Western" lifestyle and diet, being described as "a disease of Western civilization". Its increased incidence during the 20th century and the morbidity and mortality associated with complications, demand that this condition should receive greater attention in terms of aetiology, prevention and management. It is generally believed that low dietary fibre and ageing are the two main pathogenic factors involved in this disease. Physiological studies have also demonstrated that there is a higher intraluminal pressure in the large bowel with diverticula. This chapter provides the evidence currently available for the pathophysiology of colonic diverticulosis and discusses its aetiological factors, including low dietary fibre, ageing and intraluminal pressure as well as extracelluar matrix such as collagen and elastin. The difference between the left-sided diverticulosis commonly seen in Caucasians and the right-sided predominantly observed in Asians is also presented.

Clinical features and differential diagnosis of diverticular disease

Colonic diverticulosis occurs in the majority of Western populations with age, but only a small proportion of people experience symptoms. Diverticular disease usually presents with either haemorrhage or diverticulitis. A quarter of patients with diverticulitis will develop complications including perforation, fistulation, obstruction or stricture. This chapter deals with the natural history, risk factors, clinical features and differential diagnoses of symptomatic diverticular disease.

Boswell Award of the SAVA: 1991. Dr. D. G. Catton

Colonic diverticula are protrusions of the mucosa through the outer muscular layers, which are usually abnormally thickened, to form narrow necked pouches. Diverticular disease of the colon covers a wide clinical spectrum: from an incidental finding to symptomatic uncomplicated disease to diverticulitis. A quarter of patients with diverticulitis will develop potentially life-threatening complications including perforation, fistulae, obstruction or stricture. In Western countries diverticular disease predominantly affects the left colon, its prevalence increases with age and its causation has been linked to a low dietary fibre intake. Right-sided diverticular disease is more commonly seen in Asian populations and affects younger patients. Its pathogenesis and relationship to left-sided diverticular disease remains unclear. Diverticular disease of the colon is a significant cause of morbidity and mortality in the Western world and its frequency has increased throughout the whole of the 20th century. Since it is a disease of the elderly, and with an aging population, it can be expected to occupy an increasing portion of the surgical and gastroenterological workload. It is uncertain what symptoms uncomplicated diverticular disease gives rise to: there is an overlap with irritable bowel syndrome. Diagnosis is primarily by barium enema and colonoscopy, but more sophisticated imaging procedures such as computed tomography (CT) are increasingly being used to assess and treat complications such as abscess or fistula, or to provide alternative diagnoses if diverticulosis is not confirmed. Initial therapy for uncomplicated diverticulitis is supportive, including monitoring, bowel rest and antibacterials. CT is used to guide percutaneous drainage of abscesses to avoid surgery or allow it to be performed as an elective procedure. Surgery is indicated for complications of acute diverticulitis, including failure of medical treatment, gross perforation, and abscess formation that cannot be resolved by percutaneous drainage. Complications of chronic diverticulitis (fistula formation, stricture and obstruction) are also usually treated surgically. However, the indications for, and the timing and staging of operations for diverticular disease are often difficult decisions requiring sound clinical judgement. Factors such as the number of episodes of inflammation, the age of the patient, and his/her overall medical condition play a role in determining whether or not a patient should undergo surgical resection. Laparoscopic surgery may be associated with less pain, less morbidity and shorter hospital stays, but its exact role is yet to be defined. Diverticular disease of the colon is the most common cause of acute lower gastrointestinal haemorrhage, which can be massive. Although the majority of patients stop bleeding spontaneously, angiographic and surgical treatment may be required, while the place of endoscopic haemostasis remains to be established.