Diarrhoea in adults with coronavirus disease—beyond incidence and mortality: a systematic review and meta-analysis

Diarrhoea is a relatively common manifestation of coronavirus disease (COVID-19), but there is no systematic review which comprehensively describes it beyond its incidence and impact on prognosis. This study aims to provide a detailed systematic review of diarrhoea in adults with COVID-19. A PUBMED and Scopus search (until 7 September 2020) was performed. Studies that were limited to describing incidence of diarrhoea and its effect on prognosis were excluded. Twenty-six papers including 7860 patients with COVID-19 were subjected to synthesis. Mean duration of diarrhoea was 4.2 (3.6–4.9) days (range 1–16 days), whereas mean bowel movement count was 4.6 (3.8–5.3) and maximum was 20 per day. Diarrhoea started on an average 5.1 (3.8–6.5) days after disease onset but was the first manifestation in 4.3% patients. Stool occult blood was detected in 6.8% of patients with diarrhoea, while 53.3% cases had watery diarrhoea. Patients with diarrhoea also had elevated faecal calprotectin. Viral genome in faeces was detected more often in patients with diarrhoea and most often in patients without respiratory symptoms. Fever, myalgia and respiratory symptoms were observed with the same incidence in patients with and without diarrhoea. Similarly, there were no differences noted in complete blood count and most inflammation biomarkers between patients with and without diarrhoea. However, nausea, vomiting abdominal pain, sneezing and headache were more common in patients with diarrhoea. Diarrhoea was the main manifestation of COVID-19 in 6.1% of cases and this form of the disease had specific features. Diarrhoea in COVID-19 needs further investigation.