Review article: uncomplicated diverticular disease of the colon

Probiotics in the gastrointestinal diseases of the elderly

Changes of the gut microflora in elderly appear to involve a reduction in numbers of healthy bacteria (lactobacilli and bifidobacteria) and an increase in numbers of potentially pathogenic species. These changes are generally described as gastrointestinal disorders and infections. This review analyses benefits of probiotics in old people, with particular interesting for the latest researches relevant to elderly people, e.g. trials examining enteric infections, antibiotic-associated diarrhea and Clostridium difficile associated diarrhea, functional bowel problems (constipation and irritable bowel syndrome), inflammatory bowel diseases, stimulation of the immune system and prevention of cancer. A growing number of researches indicates that some probiotic strains may help to maintain the health in old people, suggesting both health and cost-saving benefits in offering fermented dairy products. These benefits include: establishment of balanced intestinal microflora; improving colonization resistance and or prevention of diarrhea; reduction of fecal enzymes; reduction of serum cholesterol; reduction of potential mutagenes; reduction of lactose intolerance; synthesis of vitamins; predigestion of proteins.

Allergic predisposition, histamine and histamine receptor expression (H1R, H2R) are associated with complicated courses of sigmoid diverticulitis

BACKGROUND

We aimed to evaluate our hypothesis that allergic predisposition and expression of histamine receptors might contribute to complicated courses of sigmoid diverticulitis.

METHODS

Expression of histamine and histamine receptors (H1R, H2R) was analysed on protein level (immunohistochemistry/immunofluorescence (IF)) as well as mRNA level (reverse transcription-PCR (RT-PCR) in surgical specimen of patients (n = 101) having undergone resection for sigmoid diverticulits (n = 57 complicated diverticulitis/n = 44 non-complicated diverticulitis).

RESULTS

The mean number of comorbid diseases per patient was 1.76 ± 1.25. Thirty-nine of 101 patients (38.6%) exhibited allergic predisposition (grass poll, food, drug, pets, etc.). Comorbid diseases were significantly associated with complicated diverticulitis (p = 0.027). Complicated sigmoid diverticulitis was significantly associated with high H1R and H2R expression (p < 0.001). Furthermore, an association of complicated diverticulitis with allergic predisposition was found (odds ratio = 3.2, p = 0.0097). IF double-labelling experiments showed a strong correlation of increased histamine expression with expression of H1R and H2R on intestinal enterocytes (histamine/H1R, rho = 0.841, p < 0.0001 and histamine/H2R, rho = 0.806, p < 0.0001). The results of increased H1R and H2R expression in complicated sigmoid diverticulitis were also detected on mRNA level in a subset of patients (RT-PCR, p = 0.009).

CONCLUSIONS

Our findings suggest that allergic predisposition might be another important risk factor for complicated courses of acute sigmoid diverticulitis and linked with histamine receptor expression. Supportive therapies with antihistaminic drugs might become an option. Allergic predisposition might be worth considering when indicating surgery for sigmoid diverticulitis.

Effects of Ficus carica paste on constipation induced by a high-protein feed and movement restriction in beagles

Constipation is one of the most common functional digestive complaints worldwide. We investigated the laxative effects of figs (Ficus carica L) in a beagle model of constipation induced by high protein diet and movement restriction. The experiments were consecutively conducted over 9 weeks divided into 3 periods of 3 weeks each. All 15 beagles were subjected to a non-treatment (control) period, a constipation induction period, and a fig paste treatment period. We administered fig paste (12 g/kg daily, by gavage) for 3 weeks following a 3-week period of constipation induction in dogs. Segmental colonic transit time (CTT) was measured by counting radiopaque markers (Kolomark) using a radiograph performed every 6 h after feeding Kolomark capsules, until capsules were no longer observed. Fig paste significantly increased fecal quantity in constipated dogs, and segmental CTT was also reduced following fig paste administration. There were no significant differences in feed intake, water intake, body weight, or blood test results, between the constipation and fig paste administration periods. Our results demonstrate that fig is an effective treatment for constipation in beagles. Specifically, stool weight increased and segmental CTT decreased. Fig pastes may be useful as a complementary medicine in humans suffering from chronic constipation.

Effects of Ficus carica paste on loperamide-induced constipation in rats

OBJECTIVE

Constipation is one of the most common gastrointestinal complaints worldwide. This study examined the effects of fig (Ficus carica L.) paste for the treatment of loperamide-induced constipation in a rat model.

METHODS

Animals were divided into one normal control group and four experimental groups (0, 1, 6, and 30 g/kg). Loperamide (2 mg/kg, twice per day) was injected intraperitoneally to induce constipation in the four experimental groups. Fig paste was administered for 4 weeks to assess its anti-constipation effects.

RESULTS

Fecal pellet number, weight and water content were increased in the fig-treated groups as compared to the control group. Reductions in body weight and increased intestinal transit length were observed in the fig-treated groups. Fecal pellet number was reduced in the distal colons of the fig-treated rats. Exercise and ileum tension increased in the experimental groups as compared to the control group. According to histological analyses, the thickness of the distal colon and areas of crypt epithelial cells that produce mucin were increased in the fig-treated groups in a dose-dependent manner.

CONCLUSION

Constipation was decreased when fig fruit was fed to rats. Specifically, fecal number, weight, and water content, as well as histological parameters such as thickness and mucin areas in the distal colon were improved. Fig treatment may be a useful therapeutic and preventive strategy for chronic constipation.

Expanding applications: the potential usage of 5-aminosalicylic acid in diverticular disease

Diverticular disease is a common bowel condition, the pathogenesis of which is incompletely understood. Acute exacerbations of diverticular disease usually require dietary changes, antibiotic therapy, and may necessitate urgent surgery. Approximately 25-33% of patients experience symptomatic and acute inflammatory disease recurrence, suggesting that current long-term management is inadequate. Because inflammatory complications of diverticular disease, including diverticulitis, are similarities to inflammatory bowel diseases, evidence suggests that patients may respond to anti-inflammatory therapies used in these conditions. Here, we explore the rationale and evidence for use of inflammatory bowel disease treatment, namely 5-aminosalicylic acid (5-ASA; mesalamine), in diverticular disease, and review clinical data on the efficacy of mesalamine either alone or in combination with other agents for the treatment of diverticular disease. PubMed and conference abstracts were searched for clinical studies examining the use of mesalamine in treating diverticular disease. Studies were evaluated for treatment efficacy in symptom reduction, recurrence prevention, or improving quality of life. The results of our search suggest that single-agent mesalamine can reduce diverticular disease symptoms and improve quality of life more effectively than antibiotic treatment alone. Mesalamine in combination with antibiotics can also reduce symptoms and improve quality of life with greater efficacy than either treatment alone. Combining mesalamine and probiotics treatments may reduce recurrent attacks of diverticular disease. Further randomized, well-controlled studies are required for validation; however, it seems that mesalamine is an important agent in future diverticular disease management.

Diverticular disease of the right colon

Background

The incidence of colonic diverticular disease varies with national origin, cultural background and diet. The frequency of this disease increases with advancing age. Right-sided diverticular disease is uncommon and reported to occur in 1-2% of surgical specimens in European and American series. In contrast the disease is more prevalent and reported in 43-50% of specimens in Asian series. Various lines of evidence suggest this variation may represent hereditary differences. The aim of the study is to report all cases of right sided diverticular disease underwent surgical resection or identified during pathological examination of right hemicoloectomy specimens

Methods

A retrospective review of all surgical specimens with right sided colonic diverticular disease selected from a larger database of all colonic diverticulosis and diverticulitis surgical specimen reported between January 1993 and December 2010 at the Pathology Department McMaster University Medical Centre Canada. The clinical and pathological features of these cases were reviewed

Results

The review identified 15 cases of right colon diverticulosis. The clinical diagnoses of these cases were appendicitis, diverticulitis or adenocarcinoma. Eight cases of single congenital perforated diverticuli were identified and seven cases were incidental multiple acquired diverticuli found in specimen resected for right side colonic carcinomas/large adenomas. Laparotomy or laparoscopic assisted haemicolectomies were done for all cases. Pathological examination showed caecal wall thickening with inflammation associated with perforated diverticuli. Histology confirmed true solitary diverticuli that exhibited in two cases thick walled vessels in the submucosa and muscular layer indicating vascular malformation/angiodysplasia. Acquired diverticuli tend to be multiple and are mostly seen in specimens resected for neoplastic right colon diseases.

Conclusion

Single true diverticular disease of the right colon is usually of congenital type and affects younger age group and may be associated with angiodysplasia in some cases. Multiple false diverticuli are more seen in association with caecal carcinoma or large adenomas. These are usually asymptomatic and are more seen in older patients. However this study dose not reflects the true incidence of the disease in the general population.

Treatment of diverticular disease of the colon and prevention of acute diverticulitis: a systematic review

BACKGROUND

Diverticular disease of the colon is a common disorder, characterized by recurrent symptoms and complications such as diverticulitis, requiring hospital admissions and surgery.

OBJECTIVE

This study aimed to systematically review the evidence for medical therapy of diverticular disease in reducing symptoms and preventing acute diverticulitis.

DATA SOURCES

MEDLINE and Embase databases (1966 to February 2010).

STUDY SELECTION

The studies selected were prospective clinical trials on uncomplicated diverticular disease of the colon.

INTERVENTIONS

Four investigators independently reviewed articles, extracted data, and assessed study quality according to standardized criteria.

MAIN OUTCOME MEASURES

The main outcomes measured were improvement in symptoms, complete remission of symptoms, and prevention of acute diverticulitis.

RESULTS

We identified 31 studies, including 6 placebo-controlled trials. The methodological quality of these studies was suboptimal. Only 10 trials provided a detailed description of the patient history, 8 assessed symptoms by the use of a validated questionnaire, and 14 appropriately defined inclusion and exclusion criteria. Only one long-term double-blind placebo-controlled study was identified. This reported a significant improvement in symptoms and greater prevalence of symptom-free patients at 1 year with fiber plus rifaximin in comparison with fiber alone. The efficacy of treatment in preventing acute diverticulitis was evaluated in 11 randomized trials. Four trials compared rifaximin plus fiber vs fiber alone and failed to show a significant difference between treatments. However, cumulative data from these trials revealed a significant benefit following rifaximin and fiber (1-year rate of acute diverticulitis: 11/970 (1.1%) vs 20/690 (2.9%); P = .012), but with a number needed to treat of 57, to prevent an attack of acute diverticulitis.

LIMITATIONS

: Heterogeneity of the study design, patients' characteristics, regimens and combination of studied treatment, and outcome reporting precluded the pooling of results and limited interpretation.

CONCLUSIONS

The treatment for diverticular disease relies mainly on data from uncontrolled studies. Treatment showed some evidence of improvement in symptoms, but its role in the prevention of acute diverticulitis remains to be defined.

Absence of mucosal inflammation in uncomplicated diverticular disease

BACKGROUND

Uncomplicated diverticular disease is a common condition in patients older than 50 years. Symptoms are aspecific and overlapping with those of irritable bowel syndrome. Nowadays, patients are often treated with antinflammatory drugs (5-aminosalicilic acid).

AIM

Our purpose was to evaluate the presence of inflammation in the colonic mucosa of patients with symptomatic uncomplicated diverticular disease compared with subjects without diverticula.

METHODS

Endoscopic biopsies of colon from 10 patients with symptomatic uncomplicated diverticular disease and 10 from subjects without diverticula (controls) were taken. Specimens were homogenised and IL2, IL4, IL5, IL8, IL10, IL12p70, IL13, IFN gamma, TNF alfa (searchlight multiplex technique), TGF beta, transglutaminase type 2 and caspase 9 were measured. Histochemistry for transglutaminase type 2 and TUNEL were performed on the histological sections, in addition to morphologic evaluation, as markers of tissue remodelling and apoptosis. For statistical analysis Student's t test and Spearman correlation test were used.

RESULTS

No histological differences were detected between the patients with an uncomplicated diverticular disease and controls. Mean values of mucosal cytokines and of the other tested parameters did not show statistically significant differences between patients with uncomplicated diverticular disease and controls.

CONCLUSIONS

Even if based on a small number of patients, the study demonstrates the absence of inflammation in the mucosa of subjects affected by uncomplicated diverticular disease.

Meta-analysis: long-term therapy with rifaximin in the management of uncomplicated diverticular disease

BACKGROUND

Diverticular disease of the colon is a common gastrointestinal disease. Although most patients remain asymptomatic for their whole life, about 20-25% present symptoms related to 'diverticular disease'. Several randomised trials verified efficacy of a poorly absorbed antibiotic, such as rifaximin-α (rifaximin), in soothing symptoms and preventing diverticulitis.

AIM

To evaluate the long-term efficacy administration of rifaximin plus fibre supplementation vs. fibre supplementation alone, on symptoms and complications, in patient with symptomatic uncomplicated diverticular disease.

METHODS

Pertinent studies were selected from the Medline, and the Cochrane Library Databases, references from published articles and reviews. Conventional meta-analysis according to DerSimonian and Laird method was used for the pooling of the results. The outcomes were 1- year complete symptom relief, and 1- year complication incidence. The rate difference (RD, with 95% CI) and the Number Needed to Treat (NNT) were used as measure of the therapeutic effect on each outcome.

RESULTS

Four prospective randomised trials including 1660 patients were selected. The pooled RD for symptom relief was 29.0% (rifaximin vs. control; 95% CI 24.5-33.6%; P<0.0001; NNT=3). The pooled RD for complication rate was -1.7% in favour of rifaximin (95% CI -3.2 to -0.1%; P=0.03; NNT=59). When considering only acute diverticulitis, the pooled RD in the treatment group was -2% (95% CI -3.4 to -0.6%; P=0.0057; NNT=50).

CONCLUSIONS

In symptomatic uncomplicated diverticular disease, treatment with rifaximin plus fibre supplementation is effective in obtaining symptom relief and preventing complications at 1 year.

Clinical significance of colonic diverticulosis associated with bowel symptoms and colon polyp

This study was done to evaluate prospectively the clinical significance of colonic diverticulosis. In the 1,030 consecutive outpatients undergoing colonoscopy, the information on the demographics, the patterns of bowel symptoms, and the prevalence of colon polyp were analyzed according to the presence of colonic diverticulosis. The mean age of 1,030 patients were 52.2 yr and 59.3% were male. The prevalence of diverticulosis was 19.7% (203/1,030). Of 203 diverticulosis patients 85.2% were in proximal group, 5.4% in distal group and 9.4% in both group. Six (3.0%) patients were found to have diverticulitis. Multivariate logistic regression analysis showed that an old age, diabetes and the presence of polyp were significant factors associated with proximal or both diverticulosis. A significant difference was demonstrated between the patients of distal diverticular group and the controls for the symptom frequency scores within the previous 4 weeks. The items, which showed difference, were hard stool, urgency, flatus, chest discomfort and frequent urination. In conclusion, old age, diabetes and the presence of colon polyp were associated with proximal diverticulosis. The temporal symptoms were more frequent in distal diverticulosis than in proximal diverticulosis in the study subjects.

Natural history of acute colonic diverticular bleeding: a prospective study in 133 consecutive patients

BACKGROUND

Bleeding recurrence rate after spontaneous haemostasis of colonic diverticular haemorrhage varies in the literature, and a small minority of patients will require endoscopic, radiological or surgical intervention.

AIM

To study the natural history of colonic diverticular bleeding in consecutive patients.

METHODS

We studied prospectively consecutive patients admitted for colonic diverticular bleeding from 1997 to 2005. Data on age, gender, 30-day mortality, therapeutic modality for bleeding management and subsequent rebleeding were collected.

RESULTS

One hundred and thirty-three patients (mean age 75.7 years) were recruited. Bleeding stopped spontaneously in 123 patients (92.4%). A more interventional approach was necessary in 10 patients. Thirty-day mortality rate for first bleeding was 2.25%. Out of the 123 patients managed conservatively and submitted to an average follow-up of 47.5 months, 17 (13.8%) presented at least one recurrent diverticular bleeding. Spontaneous haemostasis was obtained in all recurrent cases except one, who died. The estimated bleeding recurrence rate was 3.8% at 1 year, 6.9% at 5 years and 9.8% at 10 years.

CONCLUSIONS

The low estimated rebleeding rate and the fact that rebleeding can be treated conservatively in most cases suggest that an aggressive approach with intervention is not justified.

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.

Diverticular disease: A therapeutic overview

Formation of colonic diverticula, via herniation of the colonic wall, is responsible for the development of diverticulosis. When diverticulosis becomes symptomatic, it becomes diverticular disease. Diverticular disease is common in Western and industrialized countries, and it is associated with numerous abdominal symptoms (including pain, bloating, nausea, diarrhea, and constipation). Standard medical therapies with antibiotics are currently recommended for patients affected by diverticular disease. However, changing concepts on the pathophysiology of the disease suggest that diverticular disease may share many of the hallmarks of inflammatory bowel diseases. On this basis, the addition of therapies using mesalazine and probiotics may enhance treatment efficacy by shortening the course of the disease and preventing recurrences.

Rifaximin in the management of colonic diverticular disease

Rifaximin is a rifamycin derivative that acts by inhibiting bacterial RNA synthesis. Since it is virtually unabsorbed after oral administration, its bioavailability within the GI tract is high, with intraluminal and fecal drug concentrations largely exceeding the minimum inhibitory concentration values observed in vitro against a broad spectrum of bacteria, including Gram-positive and Gram-negative bacteria, both aerobes and anaerobes. The GI tract, therefore, represents the primary therapeutic target and the disorders in which intestinal bacteria have a pathogenic role represent the main indication. This is the case with colonic diverticular disease. As a consequence, the broad antibacterial activity of rifaximin appears to be of value in the treatment of this clinical condition. Clinical trials have provided evidence of the substantial benefit of rifaximin in diverticular disease. Indeed, available data show the efficacy of the drug in achieving symptomatic relief in patients with uncomplicated disease. A therapeutic gain of approximately 30%, compared with fiber supplementation only, can be expected after cyclic administration of rifaximin for 12 months. However, its value in the prevention of inflammatory complications of the disease needs to be further explored. Recent studies have shown some evidence of synergy between rifaximin and mesalazine and suggest that a combined treatment could be worthwhile in selected subsets of patients with diverticular disease.

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.

Rifaximin pharmacology and clinical implications

Rifaximin is a semisynthetic, rifamycin-based non-systemic antibiotic, with a low gastrointestinal absorption and a good antibacterial activity. The antibacterial action covers Gram-positive and Gram-negative organisms, both aerobes and anaerobes. Its antimicrobial action is based on its property to bind to the beta-subunit of bacterial DNA-dependent RNA polymerase inhibiting, thereby, the bacterial RNA synthesis. Rifaximin contributes to restore gut microflora imbalance, becoming an important therapeutic agent in several organic and functional gastrointestinal diseases such as hepatic encephalopathy, small intestine bacterial overgrowth, inflammatory bowel disease and colonic diverticular disease. This antibiotic has the advantage of low microbial resistance and few systemic adverse events and is safe in all patient populations, including young children.

Health benefits of dietary fiber

Dietary fiber intake provides many health benefits. However, average fiber intakes for US children and adults are less than half of the recommended levels. Individuals with high intakes of dietary fiber appear to be at significantly lower risk for developing coronary heart disease, stroke, hypertension, diabetes, obesity, and certain gastrointestinal diseases. Increasing fiber intake lowers blood pressure and serum cholesterol levels. Increased intake of soluble fiber improves glycemia and insulin sensitivity in non-diabetic and diabetic individuals. Fiber supplementation in obese individuals significantly enhances weight loss. Increased fiber intake benefits a number of gastrointestinal disorders including the following: gastroesophageal reflux disease, duodenal ulcer, diverticulitis, constipation, and hemorrhoids. Prebiotic fibers appear to enhance immune function. Dietary fiber intake provides similar benefits for children as for adults. The recommended dietary fiber intakes for children and adults are 14 g/1000 kcal. More effective communication and consumer education is required to enhance fiber consumption from foods or supplements.

Involvement of central immunity in uncomplicated diverticular disease

OBJECTIVE

The pathogenesis of symptoms of uncomplicated diverticular disease (UDD) is unclear, but changes in gut microflora and physiologic inflammation may be implicated. The objective of the study was to investigate the distribution of gut homing lymphocytes in peripheral blood and intestinal mucosa of UDD patients, and the effects of luminal antibiotic treatment.

MATERIAL AND METHODS

Ten UDD patients and 10 age- and gender-matched healthy subjects underwent peripheral blood sampling, and colonoscopy with biopsies taken from the transverse and sigmoid colon. Treatment consisted of a 2-month course of rifaximin 1.2 g/day for 15 days/month. Blood sample and mucosal biopsies were repeated in UDD patients at the end of treatment. Flow cytometry was performed using monoclonal antibodies (CD3, CD4, CD8, CD25, CD19, CD45, CD62L, CD103).

RESULTS

In peripheral blood, both CD4+ and CD8+/CD103+ were significantly higher in patients at baseline than in controls (0.95% versus 0.36%, and 0.5% versus 0.09%, respectively). After treatment, peripheral CD4+/CD103+ decreased (0.27%), while CD8+/CD103+ did not change (0.35%); on the contrary, peripheral CD25+ increased, the CD4+ subpopulation showing significantly higher levels than those in controls. No difference was found between lymphocytes in the diverticular sigmoid mucosa of patients at baseline and those in controls, but there was a significant decrease in CD8+/CD62L+ after treatment. In the normal transverse colon, CD4+/CD62L+ of patient at baseline were significantly lower than in controls. After treatment, CD4+/CD103+ levels significantly increased, while CD8+/CD62L+ levels significantly decreased.

CONCLUSIONS

Both central and mucosal immunity may be modified in UDD patients, with an increased recruitment of CD103+ lymphocytes. A 2-month course of rifaximin appears to reduce CD103+ levels, suggesting a decrease in mobilization of mucosal homing.

Diverticulosis and colorectal cancer: between lights and shadows

The prevalence of diverticulosis and colorectal cancer (CRC) is markedly increased in the last century. Both diseases are highly frequent in Western countries and in aged people. Western diet--low in fiber and rich in dietary fat--has been largely regarded to play a major role in the pathogenesis of both conditions. A causal relationship between diverticulosis and CRC has been suggested in different studies. Epidemiologic series found a more frequent rectosigmoid localization of neoplastic lesions (advanced adenoma and CRC) in patients with diverticulosis as compared with controls, particularly in those with a previous diverticulitis episode or with an extensive disease. However, data are still controversial, with other studies failing to confirm this observation. Such discrepancy could be referred to the highly heterogeneous study design and setting in the different epidemiologic series. Pathologic studies showed that either macroscopic and microscopic chronic inflammation--which is regarded as risk factor for CRC development--is present in the colonic mucosa of some patients with diverticula. Moreover, alterations in the extracellular matrix, also involved in colorectal carcinogenesis, have been depicted in diverticulosis. In addition, an upward shifting of cell proliferation occurs in diverticular mucosa, and in nondiverticular patients with advanced adenomas. Finally, aberrant crypt foci--which are considered potential markers of CRC risk in ulcerative colitis--have been detected in colonic mucosa of patients with diverticulosis. Despite this substantial amount of evidence, however, the available data are not yet strong enough to suggest a more aggressive CRC prevention in diverticular as compared with nondiverticular subjects.

Association between colonic polyps and diverticular disease

AIM: To evaluate the association between colonic polyps and diverticular disease in Japan.

METHODS: We retrospectively reviewed the medical records of 672 consecutive patients who underwent total colonoscopy between August 2006 and April 2007 at Nishinjo Hospital, Okinawa, Japan. Patients with a history of any of the following were excluded from the study: previous polypectomy, colonic resection, and inflammatory bowel diseases. The association between colonic polyps and diverticular disease was analyzed by logistic regression analysis, adjusted for age and sex.

RESULTS: Prevalence of colonic polyps in all patients with diverticular disease was significantly higher than that in those without diverticular disease (adjusted odds ratio 1.7).

CONCLUSION: Our data showed that patients with diverticular disease have a higher risk of colonic polyps compared to those without.

Epidemiology and management of diverticular disease of the colon

The aim of this review is mainly to show the high prevalence of diverticulosis and the clinical relevance of uncomplicated and complicated diverticular disease worldwide. The prevalence of diverticular disease is directly related to the aging of the population and in western countries is diagnosed in approximately 50–65% of adult subjects. The often more frequent adoption of an incorrect dietary style, such as a low-fiber diet, and the progressive increase in the average age of western populations will increase the prevalence of this pathology and the economic burden for health systems even more so. Furthermore, the management of uncomplicated diverticular disease, segmental colitis associated to diverticula and diverticulitis, which represent the different manifestations of the symptomatic spectrum of colonic diverticulosis, are reported.

Interaction between rifaximin and dietary fibre in patients with diverticular disease

BACKGROUND

Cyclic administration of rifaximin in association with dietary fibre achieves symptomatic relief in uncomplicated diverticular disease (DD) by means of a still undefined mechanism.

AIM

To investigate the effects of a combination of rifaximin and fibre on both hydrogen production by intestinal microflora and oro-anal transit time.

METHODS

In a controlled, double-blind crossover trial, 64 patients with uncomplicated DD were given bran (20 g/day) and randomly treated with rifaximin (1200 mg/day) or a placebo for 14 days. Evaluation was based on clinical status, breath test, oro-anal transit time and faecal weight.

RESULTS

The global symptomatic score was significantly reduced after rifaximin (7.1 +/- 4.1 to 4.1 +/- 3.3; P < 0.005) but not after placebo (6.8 +/- 3.8 to 6.1 +/- 3.5). Hydrogen production significantly increased after placebo from 198 +/- 134 to 267 +/- 161 ppm/min, while Rifaximin reduced it from 222 +/- 187 to 166 +/- 131 ppm/min (P = 0.05). The total oro-anal transit time decreased from 56.1 +/- 28.2 to 51.3 +/- 28.0 h in placebo and from 54.4 +/- 31.9 to 45.1 +/- 32.4 h (P < 0.05) in rifaximin-treated patients.

CONCLUSIONS

The administration of rifamixin improves the benefits of dietary fibre in uncomplicated DD by preventing its bacterial degradation.

Efficacy of long term cyclic administration of the poorly absorbed antibiotic Rifaximin in symptomatic, uncomplicated colonic diverticular disease

AIM: To comparatively evaluate the long term efficacy of Rifaximin and dietary fibers in reducing symptoms and/or complication frequency in symptomatic, uncomplicated diverticular disease.

METHODS: 307 patients (118 males, 189 females, age range: 40-80 years) were enrolled in the study and randomly assigned to: Rifaximin (400 mg bid for 7 d every month) plus dietary fiber supplementation (at least 20 gr/d) or dietary fiber supplementation alone. The study duration was 24 mo; both clinical examination and symptoms’ questionnaire were performed every two months.

RESULTS: Both treatments reduced symptom frequency, but Rifaximin at a greater extent, when compared to basal values. Symptomatic score declined during both treatments, but a greater reduction was evident in the Rifaximin group (6.4 ± 2.8 and 6.2 ± 2.6 at enrollment, p = NS, 1.0 ± 0.7 and 2.4 ± 1.7 after 24 mo, p < 0.001, respectively). Probability of symptom reduction was higher and complication frequency lower (Kaplan-Meyer method) in the Rifaximin group (p < 0.0001 and 0.028, respectively).

CONCLUSION: In patients with symptomatic, uncomplicated diverticular disease, cyclic administration of Rifaximin plus dietary fiber supplementation is more effective in reducing both symptom and complication frequency than simple dietary fiber supplementation. Long term administration of the poorly absorbed antibiotic Rifaximin is safe and well tolerated by the patients, confirming the usefulness of this therapeutic strategy in the overall management of diverticular disease.