To examine the relationship between gastroenteritis and the risk of microscopic colitis (MC), a casecontrolled study was carried out of 5 adult patients with MC diagnosed between 1990 and 2016 in Sweden, matched up to 5 general population controls according to age, sex, calendar year and county. Cases of MC were identified using systematized nomenclature of medicine codes from the ESPRESSO study, a cohort of gastrointestinal pathology reports from all 28 pathology centers in Sweden. Logistic regression modeling that was used to estimate adjusted odds ratio (aORs), and 95% confidence intervals (CIs).
Through December 2016, 13,466 MC cases were matched to 64,479 controls. The prevalence of previous diagnosed gastrointestinal infection was 7.5% among patients with MC, which was significantly higher than controls (3%). After adjustment, gastroenteritis was associated with an increased risk of MC (aOR 2.63). Among specific pathogens, Clostridioides difficile (aOR 4.39), Norovirus (aOR 2.87), and Escherichia species (aOR 3.82), but not Salmonella species, were associated with an increased risk of MC.
The association between gastrointestinal infections and risk of MC was stronger for the collagenous subtype (aOR 3.23), as compared with lymphocytic colitis (aOR 2.51). The associations remain significant after adjustment for immunemediated conditions and polypharmacy than when compared with unaffected siblings.
It was concluded in a nationwide study that gastrointestinal infection, particularly C. difficile, is associated with an increased risk of subsequent MC.