Risk of acute gastroenteritis following COVID-19 exposure: a retrospective population-based analysis conducted in England

Severe COVID-19 is associated with immune dysregulation, microbiome disruption, and increased vulnerability to secondary infections. However, the longer-term risk of acute gastroenteritis (AGE) following COVID-19 remains poorly studied. We compared AGE incidence among community-managed and hospitalised COVID-19 patients with test-negative controls and hospitalised sepsis patients.

Methods

We conducted a retrospective cohort study using electronic healthcare data. Patients with a recorded SARS-CoV-2 PCR test between 01 March 2020 and 01 March 2022 were allocated to test-negative, community COVID-19, or hospitalised COVID-19 cohorts. A hospitalised sepsis cohort was assembled for an age-, sex- and time-matched analysis. AGE incidence rates were calculated for the two years before enrolment and during follow-up. Negative binomial regression and conditional Poisson models estimated incidence rate ratios (IRRs) adjusting for demographic and clinical covariates.

Results

Among 788 103 patients, AGE incidence in the pre-pandemic period was higher among individuals later hospitalised with COVID-19 or sepsis compared with community cases. During follow-up, AGE incidence was slightly lower in community COVID-19 cases than test-negative controls (adjusted IRR 0·88 [95% CI 0·85–0·92]), but substantially higher among hospitalised COVID-19 patients (IRR 5·80 [95% CI: 5·38–6·25]). Matched analyses confirmed increased AGE rates compared with community controls (IRR 4·63 [95% CI: 4·15–5·17]) and hospitalised sepsis controls (IRR 1·41 [95% CI 1·21–1·64]).

Conclusions

COVID-19 hospitalisation is associated with a marked increase in AGE risk after discharge, exceeding that associated with sepsis hospitalisation. By contrast, lower AGE rates in community COVID-19 cases likely reflect baseline differences rather than protective effects of infection. Overall, these findings demonstrate heightened post-discharge vulnerability to gastrointestinal illness after COVID-19 hospitalisation and support the need for improved follow-up and surveillance strategies.

Funding

National Institute for Health Research