Diverticulosis is not associated with altered gut microbiota nor is it predictive of future diverticulitis: a population-based colonoscopy study.

BACKGROUND: The etiopathogenesis of diverticular disease is unknown. OBJECTIVE: To compare the fecal and mucosa-associated microbiota between participants with and without diverticulosis and participants who later developed diverticulitis versus those that did not from a population-based study. METHODS: The PopCol study, conducted in Stockholm, Sweden, invited a random sample of 3556 adults to participate, of which 745 underwent colonoscopy. Overall, 130 participants (17.5%) had diverticulosis. 16S rRNA gene sequencing was conducted on available sigmoid biopsy samples from 529 and fecal samples from 251 individuals. We identified individuals who subsequently developed acute diverticulitis up to 13 years after sample collection. In a case-control design matching for gender, age (+/-5 years), smoking and antibiotic exposure, we compared taxonomic composition, richness and diversity of the microbiota between participants with or without diverticulosis, and between participants who later developed acute diverticulitis versus those who did not. RESULTS: No differences in microbiota richness or diversity were observed between participants with or without diverticulosis, nor for those who developed diverticulitis compared with those who did not. No bacterial taxa were significantly different between participants with diverticulosis compared with those without diverticulosis. Individuals who later developed acute diverticulitis (2.8%) had a higher abundance of genus Comamonas than those who did not (p = .027). CONCLUSIONS: In a population-based cohort study the only significant difference was that those who later develop diverticulitis had more abundance of genus Comamonas. The significance of Comamonas is unclear, suggesting a limited role for the gut microbiota in the etiopathogenesis of diverticular disease.

The risk of colorectal cancer after an attack of uncomplicated diverticulitis.

OBJECTIVE: According to clinical guidelines, a colonoscopy is recommended after an attack of diverticulitis in order to exclude colorectal cancer (CRC). This is based on studies prior to the use of computerized tomography (CT) for confirmation of the diagnosis. We aimed to investigate the findings of a subsequent colonoscopy after an attack of uncomplicated diverticulitis. MATERIAL AND METHODS: The study cohort consisted of all patients with the diagnosis of uncomplicated diverticulitis, who underwent a subsequent colonoscopy 6-8 weeks later during a 6-years period in the National University Hospital of Iceland. The diagnosis of diverticulitis was based on clinical symptoms verified with a CT of the abdomen. Relevant clinical information was obtained from medical records and from the Icelandic Cancer Registry. RESULTS: A total of 282 patients had uncomplicated diverticulitis and 199 patients underwent endoscopy. Two patients had CRC (0.7%), diagnosed with diverticulitis but did not recover clinically. All other patients recovered clinically. Colonic polyps were found in 33 of 195 (17%) cases. In 19/33 (58%) cases the histology demonstrated hyperplastic polyps, and in 13/33 (39%) adenoma with mild dysplasia. Only 1/33 (3%) of the colonic polyps were >1 cm in size. CONCLUSIONS: Among patients experiencing an attack of uncomplicated diverticulitis the frequency of CRC was equal to what might be expected compared to the average risk in the population. In these patients a routine colonoscopy in the absence of other clinical signs of CRC seems hardly necessary, if the clinical course is uneventful and the patient recovers.

Inflammatory Bowel Disease Is not Linked to a Higher Rate of Adverse Events in Colonoscopy-a Nationwide Population-based Study in Sweden.

BACKGROUND AND AIMS: Inflammatory bowel disease may cause long-standing inflammation and fibrosis and may increase the risk of adverse events in colonoscopy. We evaluated whether inflammatory bowel disease and other potential risk factors are associated with bleeding or perforation in a nationwide, population-based, Swedish study. METHODS: Data from 969 532 colonoscopies, including 164 012 [17%] on inflammatory bowel disease patients, between 2003 and 2019, were retrieved from the National Patient Registers. ICD-10 codes for bleeding [T810] and perforation [T812] within 30 days of the colonoscopy were recorded. Multivariable logistic regression was used to test if inflammatory bowel disease status, inpatient setting, time period, general anaesthesia, age, sex, endoscopic procedures, and antithrombotic treatment were associated with higher odds for bleeding and perforation. RESULTS: Bleeding and perforation were reported in 0.19% and 0.11% of all colonoscopies, respectively. Bleeding [odds ratio 0.66, p <0.001] and perforation [odds ratio 0.79, p <0.033] were less likely in colonoscopies in individuals with inflammatory bowel disease status. Bleeding and perforation were more common in inpatient than in outpatient inflammatory bowel disease colonoscopies. The odds for bleeding but not perforation increased between 2003 to 2019. General anaesthesia was associated with double the odds for perforation. CONCLUSIONS: Individuals with inflammatory bowel disease did not have more adverse events compared with individuals without inflammatory bowel disease status. However, the inpatient setting was associated with more adverse events, particularly in inflammatory bowel disease status. General anaesthesia was associated with a greater risk of perforation.