Morphologic Basis for Developing Diverticular Disease, Diverticulitis, and Diverticular Bleeding

The Assessment of Knowledge, Awareness and Practice Regarding Diverticulitis and Its Risk Factors Among the Population of Saudi Arabia

Background The term "diverticula" refers to the existence of diverticula in the gastrointestinal tract but is mainly located in the sigmoid colon and is used to describe colonic diverticulosis. Diverticula, which are sac-like protrusions in the wall of the large bowel, are becoming more prevalent globally, in both developed and developing nations. This increase in occurrence is primarily attributed to changes in dietary and lifestyle patterns. Raising public awareness can potentially contribute to a decrease in the incidence of the disease and its associated complications. Aim This study aims to assess knowledge and awareness levels among the Saudi Arabian population regarding diverticulitis and its risk factors. Methods A descriptive cross-sectional study was conducted in Saudi Arabia between 1st January 2024 to 1st April 2024 using an online questionnaire for data collection. The target population consists of individuals who are between 18 years and 45, in Saudi Arabia without a history of diverticulitis. The study questionnaire covered participants' demographic (Western, Central, Southern, Eastern, Northern) regions, knowledge, awareness and practice of diverticulitis. Results A total of 548 eligible participants completed the study questionnaire, most of them (80.3%; 395) were from the Western region including Mecca, Medina and Jeddah. Participants' ages ranged from 18 to more than 40 years with a mean age of 30.5 ± 11.9 years old. A greater percentage (72.3%) of the participants were males compared to the percentage of females, which was 27.7%. The vast majority of the study participants had an inadequate knowledge level about diverticulitis (85.9%; 471) while only 31 (5.7%) had adequate knowledge and awareness about the disease. The most reported sources of information included study courses (6.4%), media (5.3%), and physicians (4.7%) while most respondents (83.6%) had no source. Conclusion In conclusion, aside from preventive strategies, the current study found that the public knew very little about diverticulitis, including its risk factors, clinical presentation, and diagnostic process. The two significant predictors of public awareness level were age and doctors as information sources.

Proportion of Colonic Diverticulosis and Its Associated Factors among Patients Underwent Colonoscopy

Aim: Diverticular disease is one of the most common gastrointestinal disorders to date, with a notable rising trend in developing countries. However, the proportion of colonic diverticulosis and its associated factors among patients who have undergone colonoscopy remains controversial. This study aimed to determine the local data on the proportion of diverticular disease in the community, its complications, the association of diverticulosis with diabetes mellitus and hypertension, as well as demographic characteristics. Material and Methods: A retrospective review of medical records was performed among patients who had undergone colonoscopy between January and December 2019. Demographic and clinical characteristics, the presence of diabetes mellitus, hypertension, and diverticular disease and its complications were examined, and the association of diverticular disease and its complications with demographic and clinical characteristics were analyzed. Results: Out of 221 patients, 12.7% (n=28) of them had diverticular diseases with a slightly predominant right-sided occurrence (42.9%, n=12). There were significant associations with age (p=0.002), ethnicity (p=0.011), and hypertension (p=0.036), but not with gender and diabetes mellitus (p=0.261, and p=0.334, respectively). There was no significant association between hypertension and recurrence of complicated diverticulitis (p=0.741), septic complications (p=0.678), and diverticular bleeding (p=0.243). Diabetes mellitus was significantly associated with diverticular bleeding complications (p=0.001) but not with septic complications (p=0.418) and recurrence of complicated diverticulitis (p=0.629). Conclusion: This study showed almost a similar percentage of diverticulosis compared to previous local studies. Age, ethnicity, and hypertension were associated with the presence of diverticulosis, and diabetes mellitus was associated with diverticular bleeding.

Concomitant diverticulosis among patients undergoing liver transplantation. Does it influence the length of hospitalization after the procedure?

Aim of the study

We tried to assess the influence of concomitant diverticulosis and other factors, e.g., Child-Pugh (C-P) and MELD scores, viral etiology, and presence of alcoholic disease, on short-term results of liver transplantation (LT) with an emphasis on duration of patient's hospitalization.

Material and methods

This prospective study was performed on 206 cirrhotic patients who were selected for LT. In order to assess the presence of diverticculosis we performed colonoscopy.

Results

The duration of hospitalization after LT did not differ significantly between patients with and without diverticulosis (27.5 [21.0-33.5] vs. 24.0 [18.0-32.0] days, p = 0.28). Patients with C-P class C were hospitalized longer in comparison to the class B patients. It is reflected in the positive correlation between C-P score and days of hospitalization (r = 0.22, p = 0.002). Patients with diverticulosis were significantly older (59.6 [51.1-63.3] vs. 52.9 [43.8-59.2] years, p = 0.03). Alcoholic liver disease (ALD) was associated with a greater risk of diverticulosis (OR = 3.89, 95% CI [1.13-15.87], p = 0.04).

Conclusions

Presence of diverticulosis among subjects undergoing LT did not influence the duration of hospitalization after the procedure. Significantly longer hospitalization was observed in patients with the most advanced liver disease according to C-P score. To determine the exact impact of diverticulosis on short-term results of LT additional studies are required.

Impact of Oral Probiotics in Amelioration of Immunological and Inflammatory Responses on Experimentally Induced Acute Diverticulitis

Acute diverticulitis is inflammation of a colon diverticulum; it represents a major cause of morbidity and mortality. The alteration of gut microbiota contributes to the promotion of inflammation and the development of acute diverticulitis disease. Probiotics can modify the gut microbiota, so they are considered a promising option for managing diverticulitis disease. This study aimed to investigate the potential protective effect of probiotics, alone or in combination with amoxicillin, on the experimentally induced model of acute diverticulitis disease. Forty-two rats were divided into seven groups as follows: control group: received water and food only; DSS group: received 3% dextran sulfate sodium (DSS) daily for 7 days; LPS group: injected with lipopolysaccharide (LPS) enema at the dose of (4 mg/kg); probiotics group: treated with probiotics (Lactobacillus acidophilus and Bifidobacterium lactis) each of which (4 × 108 CFU suspended in 2 ml distilled water) orally for 7 days; DSS/LPS group: received DSS and LPS; DSS/LPS treated with probiotics group; DSS/LPS treated with probiotics and amoxicillin group. The results revealed that both treatments (probiotics and probiotics-amoxicillin) attenuated DSS/LPS-induced diverticulitis, by restoring the colonic antioxidant status, ameliorating inflammation (significantly reduced TNF-α, interleukins, interferon-γ, myeloperoxidase activity, and C-reactive protein), decreasing apoptosis (through downregulating caspase-3), and reduction of the colon aerobic bacterial count. These probiotic strains were effective in preventing the development of the experimentally induced acute diverticulitis through the anti-inflammatory and immunomodulatory effects and have affected gut microbiota, so they can be considered a potential option in treating acute diverticulitis disease.

150 risk variants for diverticular disease of intestine prioritize cell types and enable polygenic prediction of disease susceptibility

We conducted a genome-wide association study (GWAS) analysis of diverticular disease (DivD) of intestine within 724,372 individuals and identified 150 independent genome-wide significant DNA variants. Integration of the GWAS results with human gut single-cell RNA sequencing data implicated gut myocyte, mesothelial and stromal cells, and enteric neurons and glia in DivD development. Ninety-five genes were prioritized based on multiple lines of evidence, including SLC9A3, a drug target gene of tenapanor used for the treatment of the constipation subtype of irritable bowel syndrome. A DivD polygenic score (PGS) enables effective risk prediction (area under the curve [AUC], 0.688; 95% confidence interval [CI], 0.645-0.732) and the top 20% PGS was associated with ∼3.6-fold increased DivD risk relative to the remaining population. Our statistical and bioinformatic analyses suggest that the mechanism of DivD is through colon structure, gut motility, gastrointestinal mucus, and ionic homeostasis. Our analyses reinforce the link between gastrointestinal disorders and the enteric nervous system through genetics.

Microbiota of the Colonic Diverticula in the Complicated Form of Diverticulitis: A Case Report

Intestinal microbiota appears to be implicated in the pathogenesis of diverticular disease. We present the case of a patient with diverticular colon disease complicated by a pelvic abscess. During the successful surgical treatment, two specimens were taken from the resected colon segment for the microbiota analysis: an inflamed and perforated diverticulum and a diverticulum without signs of inflammation. Culturing and 16S rRNA gene sequencing revealed significant changes in the microbial community structure and composition associated with the acute inflammation and perforation of the colonic diverticulum. The characteristics that are usually associated with the inflammatory process in the gut, namely reduced microbial diversity and richness, decreased Firmicutes-to-Bacteroidetes (F/B) ratio, depletion of butyrate-producing bacteria, and Enterobacteriaceae blooming, were more pronounced in the non-inflamed diverticulum rather than in the adjacent inflamed and perforated one. This is the first study of the intraluminal microbiota of the diverticular pockets, which is more relevant to the etiology of diverticular disease than mucosa-associated microbiota via biopsies and luminal microbiota via fecal samples.

Pathophysiology of Diverticular Disease: From Diverticula Formation to Symptom Generation

Diverticular disease is a common clinical problem, particularly in industrialized countries. In most cases, colonic diverticula remain asymptomatic throughout life and sometimes are found incidentally during colonic imaging in colorectal cancer screening programs in otherwise healthy subjects. Nonetheless, roughly 25% of patients bearing colonic diverticula develop clinical manifestations. Abdominal symptoms associated with diverticula in the absence of inflammation or complications are termed symptomatic uncomplicated diverticular disease (SUDD). The pathophysiology of diverticular disease as well as the mechanisms involved in the shift from an asymptomatic condition to a symptomatic one is still poorly understood. It is accepted that both genetic factors and environment, as well as intestinal microenvironment alterations, have a role in diverticula development and in the different phenotypic expressions of diverticular disease. In the present review, we will summarize the up-to-date knowledge on the pathophysiology of diverticula and their different clinical setting, including diverticulosis and SUDD.

The Potential Link between Episodes of Diverticulitis or Hemorrhoidal Proctitis and Diets with Selected Plant Foods: A Case-Control Study

Diverticulitis and hemorrhoidal proctitis in the population are significant public health problems. We studied the potential association between the intake of certain plant foods and diverticulitis or hemorrhoidal episodes through a case-control study including 410 cases and 401 controls. We used a semiquantitative food frequency questionnaire. The intake was additionally quantified according to a 24 h recall. The plant foods or derived food products were categorized by their main chemical components into ethanol, caffeine/theine/theobromine, capsaicin, alliin, acids, eugenol, and miscellaneous foods such as curcumin. The mean score for overall intake of plant foods under consideration was 6.3 points, and this was significantly higher in cases (8.5) than in controls (4.1). Overall intake was similar in cases presenting with diverticulitis or hemorrhoidal proctitis. Cases had 13 times the odds of being in the upper quartile for overall intake (>7 points), compared to controls. Explanatory logistic regression models showed that the strongest association with diverticulitis and hemorrhoidal proctitis was shown by the chemical food group of capsaicin, followed by ethanol, eugenol, caffeine/theine/theobromine, and acids. Neither alliin nor miscellaneous food groups showed any association. High, frequent consumption of capsaicin, followed by ethanol, eugenol, caffeine/theine/theobromine, and acids increase the risk of diverticulitis and hemorrhoidal proctitis.

The Effects of Diverticulum Localization and Hinchey Classification on Recurrence and Complications in Acute Colonic Diverticulitis

Objectives:

Diverticular disease of the colon is a pathology that arises from outward ballooning of the mucosa due to some weakness in the muscle layer. Diverticular disease may range from symptomatic uncomplicated diverticular disease to symptomatic disease with complications, such as acute diverticulitis or diverticular bleeding. Acute colonic diverticulitis occurs in about 10- 25% of patients.

Methods:

In this study, 134 patients who were admitted to our emergency clinic with complaints of abdominal pain between 2016-2019 and hospitalized with the diagnosis of acute diverticulitis were included. Patients’ sex, age, presence of additional disease, increase in leukocyte and C-reactive protein (CRP), localization of diverticulitis, Hinchey classification, mean length of hospital stay and treatment were evaluated. The effects of these parameters on complications and recurrence were statistically analyzed.

Results:

The length of hospital stay was statistically significantly associated positively with the Hinchey classification (p<0.001). While 18 patients who were medically treated developed recurrence later, and this rate was statistically significant (p<0.001). When one of the factors, localization, which may play a role in the severity of the disease and recurrence are examined, was evaluated concerning its results in our study, we found that rectosigmoid location is an important factor for recurrence. We found that the localization in the colon and the severity of the disease were effective in the prognosis of acute diverticulitis.

Conclusion:

We believe that localization and the severity of the disease should be taken into consideration when planning surgery in these patients.

Colonic diverticular disease

Diverticula are outpouchings of the intestinal wall and are common anatomical alterations detected in the human colon. Colonic diverticulosis (the presence of diverticula in the colon; referred to as diverticulosis) remains asymptomatic in most individuals but ~25% of individuals will develop symptomatic diverticulosis, termed colonic diverticular disease (also known as diverticular disease). Diverticular disease can range in severity from symptomatic uncomplicated diverticular disease (SUDD) to symptomatic disease with complications such as acute diverticulitis or diverticular haemorrhage. Since the early 2000s, a greater understanding of the pathophysiology of diverticulosis and diverticular disease, which encompasses genetic alterations, chronic low-grade inflammation and gut dysbiosis, has led to improvements in diagnosis and management. Diagnosis of diverticular disease relies on imaging approaches, such as ultrasonography, CT and MRI, as biomarkers alone are insufficient to establish a diagnosis despite their role in determining disease severity and progression as well as in differential diagnosis. Treatments for diverticular disease include dietary fibre, pharmacological treatments such as antibiotics (rifaximin), anti-inflammatory drugs (mesalazine) and probiotics, alone or in combination, and eventually surgery. Despite being effective in treating primary disease, their effectiveness in primary and secondary prevention of complications is still uncertain.

Pressure overload changes mesenteric afferent nerve responses in a stress-dependent way in a fasting rat model

It is well known that overload changes the mechanical properties of biological tissues and fasting changes the responsiveness of intestinal afferents. This study aimed to characterize the effect of overload on mechanosensitivity in mesenteric afferent nerves in normal and fasted Sprague-Dawley rats. Food was restricted for 7 days in the Fasting group. Jejunal whole afferent nerve firing was recorded during three distensions, i.e., ramp distension to 80 cmH₂O luminal pressure (D1), sustained distension to 120 cmH₂O for 2 min (D2), and again to 80 cmH₂O (D3). Multiunit afferent recordings were separated into low-threshold (LT) and wide-dynamic-range (WDR) single-unit activity for D1 and D3. Intestinal deformation (strain), distension load (stress), and firing frequency of mesenteric afferent nerve bundles [spike rate increase ratio (SRIR)] were compared at 20 cmH₂O and 40 cmH₂O and maximum pressure levels among distensions and groups. SRIR and stress changes showed the same pattern in all distensions. The SRIR and stress were larger in the Fasting group compared to the Control group (P < 0.01). SRIR was lower in D3 compared to D1 in controls (P < 0.05) and fasting rats (P < 0.01). Total single units and LT were significantly lower in Fasting group than in Controls at D3. LT was significantly higher in D3 than in D1 in Controls. Furthermore, correlation was found between SRIR with stress (R = 0.653, P < 0.001). In conclusion, overload decreased afferent mechanosensitivity in a stress-dependent way and was most pronounced in fasting rats. Fasting shifts LT to WDR and high pressure shifts WDR to LT in response to mechanical stimulation.

Impaired Expression of Neuregulin 1 and Nicotinic Acetylcholine Receptor β4 Subunit in Diverticular Disease

Neuregulin 1 (NRG1) regulates the expression of the nicotinic acetylcholine receptor (nAChR) and is suggested to promote the survival and maintenance of the enteric nervous system (ENS), since deficiency of its corresponding receptor complex ErbB2/ErbB3 leads to postnatal colonic aganglionosis. As diverticular disease (DD) is associated with intestinal hypoganglionosis, the NRG1-ErbB2/ErbB3 system and the nAChR were studied in patients with DD and controls. Samples of tunica muscularis of the sigmoid colon from patients with DD (n = 8) and controls (n = 11) were assessed for mRNA expression of NRG1, ErbB2, and ErbB3 and the nAChR subunits α3, α5, α7, β2, and β4. Site-specific gene expression levels of the NRG1-ErbB2/3 system were determined in myenteric ganglia harvested by laser microdissection (LMD). Localization studies were performed by immunohistochemistry for the NRG1-ErbB2/3 system and nAChR subunit β4. Rat enteric nerve cell cultures were stimulated with NRG1 or glial-cell line derived neurotrophic factor (GDNF) for 6 days and mRNA expression of the aforementioned nAchR was measured. NRG1, ErbB3, and nAChR subunit β4 expression was significantly down-regulated in both the tunica muscularis and myenteric ganglia of patients with DD compared to controls, whereas mRNA expression of ErbB3 and nAChR subunits β2, α3, α5, and α7 remained unaltered. NRG1, ErbB3, and nAChR subunit β4 immunoreactive signals were reduced in neuronal somata and the neuropil of myenteric ganglia from patients with DD compared to control. nAChR subunit β4 exhibited also weaker immunoreactive signals in the tunica muscularis of patients with DD. NRG1 treatment but not GDNF treatment of enteric nerve cell cultures significantly enhanced mRNA expression of nAchR β4. The down-regulation of NRG1 and ErbB3 in myenteric ganglia of patients with DD supports the hypothesis that intestinal hypoganglionosis observed in DD may be attributed to a lack of neurotrophic factors. Regulation of nAChR subunit β4 by NRG1 and decreased nAChR β4 in patients with DD provide evidence that a lack of NRG1 may affect the composition of enteric neurotransmitter receptor subunits thus contributing to the intestinal motility disorders previously reported in DD.

Etiopathogenetic Mechanisms in Diverticular Disease of the Colon

This article reviews epidemiological evidence of heritability and putative mechanisms in diverticular disease, with greatest attention to 3 recent studies of genetic associations with diverticular disease based on genome-wide or whole-genome sequencing studies in large patient cohorts. We provide an analysis of the biological plausibility of the significant associations with gene variants reported and highlight the relevance of ANO1, CPI-17 (aka PPP1R14A), COLQ6, COL6A1, CALCB or CALCA, COL6A1, ARHGAP15, and S100A10 to colonic neuromuscular function and tissue properties that may result in altered compliance and predispose to the development of diverticular disease. Such studies also identify candidate genes for future studies.

Diverticulosis and nine connective tissue disorders: epidemiological support for an association

Purpose: An underlying connective tissue disorder (CTD) may predispose to formation of intestinal diverticula. We assess the association of diverticulosis with nine selected CTDs, to inform the pathophysiology of diverticula. Methods: A population-based period-prevalence study. Individuals (3.5 million New Zealand residents born 1901-1986) with a health system record 1999-2016 were grouped into those with a hospital diagnosis of diverticulosis or diverticulitis (ICD-10-AM K57), and those without. Also recorded were any hospital diagnoses of nine selected CTDs. The association of exposure to diverticulosis and each CTD was assessed using logistic regressions adjusted for age, gender, ethnicity and region. Results: In all, 85,958 (2.4%) people had a hospital diagnosis of diverticulosis. Hospitalisation with diverticulosis was highly significantly associated with rectal prolapse (adjusted odds ratio [OR] = 3.9), polycystic kidney disease (OR = 3.8), heritable syndromes (Marfan or Ehlers-Danlos) (OR = 2.4), female genital prolapse (OR = 2.3), non-aortic aneurysm (OR = 2.3), aortic aneurysm (OR = 2.2), inguinal hernia (OR = 1.9) and dislocations of shoulder and other joints (OR = 1.7), but not subarachnoid haemorrhage (OR = 1.0). Conclusion: People with diverticulosis are more likely to have colonic extracellular matrix (ECM)/connective tissue alterations in anatomical areas other than the bowel, suggesting linked ECM/connective tissue pathology. Although biases may exist, the results indicate large-scale integrated studies are needed to investigate underlying genetic pathophysiology of colonic diverticula, together with fundamental biological studies to investigate cellular phenotypes and ECM changes.

Hypertension control and risk of colonic diverticulosis

BACKGROUND

The prevalence of diverticulosis has increased in our aging population, but the risk factors for diverticulosis are not fully understood. The role of hypertension in the risk of diverticulosis remains uncertain. This study investigated whether hypertension is associated with asymptomatic colorectal diverticulosis.

METHODS

This study enrolled asymptomatic patients who received a colonoscopy as part of a health check. Hypertension was defined by actual measured blood pressure. Logistic regression models were used to examine the relationship between hypertension and diverticulosis. In addition, we established three logistic regression models for covariate adjustment, and further stratified patients with hypertension into three subgroups based on their type of hypertension.

RESULTS

The study group consisted of 2748 participants, including 141 participants with diverticulosis and 2607 participants without diverticulosis. After adjustments for potential covariates, the odds ratio (OR) for having diverticulosis was 1.83 (95% confidence interval, 1.21-2.75, p = 0.004) in the hypertension group compared with the group without hypertension. In subgroup analyses, hypertension without antihypertensive medication use, and hypertension despite the use of antihypertensive medication were also significantly associated with the occurrence of asymptomatic diverticulosis (OR = 1.73, p = 0.028; OR = 2.07, p = 0.013, respectively). Current normal blood pressure under antihypertensive drug therapy was not associated with diverticulosis (OR = 1.74, p = 0.092).

CONCLUSIONS

Our findings suggest a positive association between hypertension and diverticulosis. Participants with poorly controlled blood pressure were found to have a higher risk of asymptomatic diverticulosis. Our study presents epidemiologic evidence for future prevention strategies against diverticulosis.

Ultrastructural changes of the human enteric nervous system and interstitial cells of Cajal in diverticular disease

BACKGROUND

In spite of numerous advances in understanding diverticular disease, its pathogenesis remains one of the main problems to be solved. We aimed to investigate the ultrastructural changes of the enteric nervous system in unaffected individuals, in asymptomatic patients with diverticulosis and in patients with diverticular disease.

METHODS

Transmission electron microscopy was used to analyse samples of the myenteric, outer submucosal and inner submucosal plexuses from patients without diverticula (n=9), asymptomatic patients with diverticulosis (n=7) and in patients with complicated diverticular disease (n=9). We described the structure of ganglia, interstitial cells of Cajal and enteric nerves, as well as their relationship with each other. The distribution and size of nerve processes were analysed quantitatively.

RESULTS

In complicated diverticular disease, neurons exhibited larger lipofuscin-like inclusions, their membranous organelles had larger cisterns and the nucleus showed deeper indentations. Nerve remodeling occurred in every plexus, characterised by an increased percentage of swollen and fine neurites. Interstitial cells of Cajal had looser contacts with the surrounding cells and showed cytoplasmic depletion and proliferation of the rough endoplasmic reticulum. In asymptomatic patients with diverticulosis, alterations of enteric nerves and ICC were less pronounced.

CONCLUSIONS

In conclusion, the present findings suggest that most ultrastructural changes of the enteric nervous system occur in complicated diverticular disease. The changes are compatible with damage to the enteric nervous system and reactive remodeling of enteric ganglia, nerves and interstitial cells of Cajal. Disrupted architecture of enteric plexuses might explain clinical and pathophysiological changes associated with diverticular disease.

Prevalence of alpha-1-antitrypsin deficiency carriers in a population with and without colonic diverticula. A multicentre prospective case-control study: the ALADDIN study

PURPOSE

The underling pathophysiological mechanisms that cause the formation of colonic diverticula (diverticulosis) remain unclear. Connective tissue changes due to ageing that cause changes in collagen structure of the colonic wall is one theory. Alpha-1-antitrypsin (A1AT) is a protease inhibitor known to protect connective tissue in other organs. Associations between (carriers of) A1AT deficiency and the development of colonic diverticula will be the main focus of this study.

METHODS

A multicentre prospective case-controlled study. In total, 230 patients ≥ 60 years with acute abdominal pain undergoing an abdominal computed tomography (CT) will be included. The research group consists of patients with diverticulosis and/or diverticulitis; controls are patients without diverticula (0 to ≤ 5 diverticula). Genotype analysis for A1AT deficiency will be performed.

RATIONALE

Hypothetically, connective tissue changes, in particular related to (carriers of) A1AT deficiency, can contribute to the development of diverticula and diverticulitis. We expect to find a higher prevalence of A1AT carriers in patients with diverticulosis compared to patients without diverticulosis. Having diverticulosis does not affect the general health of these individuals per se, when asymptomatic. Once an association is found, present findings can be the basis for a second study to assess the risk of developing acute diverticulitis and its disease course in carriers of A1AT deficiency. Because a large cohort is needed in the latter, we shall first perform a pilot study to investigate the likelihood of the primary hypothesis.

TRIAL REGISTRATION

Netherlands Trial register, NTR6251, NL55016.094.15.

Epidemiology, Pathophysiology, and Treatment of Diverticulitis

Diverticulitis is a prevalent gastrointestinal disorder that is associated with significant morbidity and health care costs. Approximately 20% of patients with incident diverticulitis have at least 1 recurrence. Complications of diverticulitis, such as abdominal sepsis, are less likely to occur with subsequent events. Several risk factors, many of which are modifiable, have been identified including obesity, diet, and physical inactivity. Diet and lifestyle factors could affect risk of diverticulitis through their effects on the intestinal microbiome and inflammation. Preliminary studies have found that the composition and function of the gut microbiome differ between individuals with vs without diverticulitis. Genetic factors, as well as alterations in colonic neuromusculature, can also contribute to the development of diverticulitis. Less-aggressive and more-nuanced treatment strategies have been developed. Two multicenter, randomized trials of patients with uncomplicated diverticulitis found that antibiotics did not speed recovery or prevent subsequent complications. Elective surgical resection is no longer recommended solely based on number of recurrent events or young patient age and might not be necessary for some patients with diverticulitis complicated by abscess. Randomized trials of hemodynamically stable patients who require urgent surgery for acute, complicated diverticulitis that has not improved with antibiotics provide evidence to support primary anastomosis vs sigmoid colectomy with end colostomy. Despite these advances, more research is needed to increase our understanding of the pathogenesis of diverticulitis and to clarify treatment algorithms.

Incidence, Risk Factors, and Clinical Effects of Recurrent Diverticular Hemorrhage: A Large Cohort Study

BACKGROUND & AIMS

Although recurrent diverticular hemorrhage is common, its incidence and risk factors have not been measured outside of small institutional cohorts. We analyzed the incidence of and risk factors for recurrent diverticular hemorrhage and whether discontinuing anticoagulation after diverticular hemorrhage is associated with ischemic stroke.

METHODS

We performed a retrospective cohort study of patients enrolled in the OptumInsight Clinformatics database from 2000 through 2016. Incidence rates for initial and recurrent diverticular hemorrhage were calculated by identifying patients who had hospitalizations with a primary discharge diagnosis consistent with diverticular hemorrhage. The hazard ratios of second diverticular hemorrhage associated with anticoagulants or platelet aggregation inhibitors were calculated using Cox proportional hazards regression adjusted for demographics, comorbidities, and medication use. The hazard ratio for ischemic stroke among patients who discontinued anticoagulation after diverticular hemorrhage was calculated similarly.

RESULTS

In the cohort analyzed, 14,925 patients had an initial diverticular hemorrhage; 1368 of these patients had a second episode. The unstandardized incidence rates of initial and second diverticular hemorrhage were 10.9 per 100,000 person-years (95% confidence interval [CI] 10.7-11.0) and 3625.6 per 100,000 person-years (95% CI 3436.0-3823.0). Platelet aggregation inhibitors were associated with second episodes of diverticular hemorrhage (hazard ratio 1.47; 95% CI 1.15-1.88), whereas all classes of anticoagulation agents were not associated. Among patients with a potential indication for stroke prophylaxis, those who discontinued anticoagulation after the diverticular hemorrhage had an increased hazard of ischemic stroke (hazard ratio 1.93; 95% CI 1.17-3.19).

CONCLUSIONS

In this retrospective cohort study, platelet aggregation inhibitors, but not anticoagulants, were associated with recurrent diverticular hemorrhage. Discontinuing anticoagulation was associated with increased hazard for ischemic stroke.

Inflammation management in acute diverticulitis: current perspectives

The pathogenesis of diverticular disease and acute diverticulitis is still unclear and many different hypotheses have been formulated. Seemingly, there are several related factors such as chronic inflammation, gut microbiome, obesity and the immunogenic properties of fat tissue and diet. Inflammation plays a pivotal role in diverticular disease and acute diverticulitis. The aim of the present review is to investigate the role of inflammation in diverticular disease as well as in mild and complicated acute diverticulitis with a focus on current research and treatment perspectives.

Recent advances in understanding and managing diverticulitis

In the past few decades, the increasing socioeconomic burden of acute diverticulitis (AD) has become evident, and with the growth of the population age, this significant economic impact will likely continue to rise. Furthermore, recent evidence showed an increased rate of hospital admissions especially evident among women and younger individuals. The natural history and pathophysiology of this clinical condition is still to be fully defined, and efforts continue to be made in the identification of risk factors and the establishment of relative preventive strategies. The actual therapeutic strategies aimed to modulate gut microbiota, such as rifaximin or probiotics, or to reduce mucosal inflammation, such as mesalazine, present a relatively poor efficacy for both the prevention of the first AD episode (primary prevention) and its recurrence (secondary prevention). In the last few years, the main goal achieved has been in the management of AD in that uncomplicated AD can, to a larger extent, be managed in an outpatient setting with no or little supportive therapy, a strategy that will certainly impact on the health costs of this disease. The problem of AD recurrence remains a topic of debate. The aim of this review is to present updated evidence on AD epidemiology and relative open clinical questions and to analyze in detail predisposing and protective factors with an attempt to integrate their possible modes of action into the several pathogenic mechanisms that have been suggested to contribute to this multifactorial disease. A unifying hypothesis dealing with the colonic luminal and extra-luminal microenvironments separately is provided. Finally, evidence-based changes in therapeutic management will be summarized. Because of an ascertained multifactorial pathogenesis of uncomplicated and complicated AD, it is probable that a single 'causa prima' will not be identifiable, and a better stratification of patients could allow one to pursue tailored therapeutic algorithm strategies.

No neuronal loss, but alterations of the GDNF system in asymptomatic diverticulosis

Background

Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor known to promote the survival and maintenance of neurons not only in the developing but also in the adult enteric nervous system. As diverticular disease (DD) is associated with reduced myenteric neurons, alterations of the GDNF system were studied in asymptomatic diverticulosis (diverticulosis) and DD.

Methods

Morphometric analysis for quantifying myenteric ganglia and neurons were assessed in colonic full-thickness sections of patients with diverticulosis and controls. Samples of tunica muscularis (TM) and laser-microdissected myenteric ganglia from patients with diverticulosis, DD and controls were analyzed for mRNA expression levels of GDNF, GFRA1, and RET by RT-qPCR. Myenteric protein expression of both receptors was quantified by fluorescence-immunohistochemistry of patients with diverticulosis, DD, and controls.

Results

Although no myenteric morphometric alterations were found in patients with diverticulosis, GDNF, GFRA1 and RET mRNA expression was down-regulated in the TM of patients with diverticulosis as well as DD. Furthermore GFRA1 and RET myenteric plexus mRNA expression of patients with diverticulosis and DD was down-regulated, whereas GDNF remained unaltered. Myenteric immunoreactivity of the receptors GFRα1 and RET was decreased in both asymptomatic diverticulosis and DD patients.

Conclusion

Our data provide evidence for an impaired GDNF system at gene and protein level not only in DD but also during early stages of diverticula formation. Thus, the results strengthen the idea of a disturbed GDNF-responsiveness as contributive factor for a primary enteric neuropathy involved in the pathogenesis and disturbed intestinal motility observed in DD.