Introduction
Diarrhea, vomiting and fever are common symptoms in children, while the
fifth most common clinical findings of COVID-19 disease are
gastrointestinal symptoms. On the other hand, the hypothesis that
SARS-CoV-2 is much lower in children than in adults has been questioned.
And the evidence suggests that prevalence of SARS-CoV-2 in children is
not 2%, but 15%. [1] Now, the question arises that, in which
patients should we suspect SARS-CoV-2 related gastroenteritis given that
diarrhea can have viral, bacterial, parasitic, and non-infectious
causes?
Clinical studies have shown that, expression of the
Angiotensin-Converting Enzyme 2 (ACE2) is not only high in the lung AT2
cells, but also in GI tract especially upper esophagus, liver,
epithelial cells and absorptive enterocytes from ileum and colon [2,
3] and then, gastrointestinal symptoms such as diarrhea will occur.
According to studies, intestinal involvement and diarrhea is seen in 2%
to 50% of COVID-19 cases, as well as in 20 to 30 % of cases,
gastrointestinal findings such as diarrhea are the first presentation of
the disease and pulmonary symptoms appear in the following days. So
involvement of the gastrointestinal tract and lungs may occur
independently of each other.[4]
Usually at this stage of the disease, there is diarrhea without mucus
and blood, but if there are complications such as pseudomembranous
colitis, intussusception and HUS, there will be exudative diarrhea.
Although in COVID-19 disease, diarrhea may be due to drug side effects,
but the gastrointestinal tract can be directly involved through ACE2
receptors and indirectly through the gut lung axis. Also in Multi
systemic inflammatory syndrome (MIS-C) caused by SARS-CoV-2, diarrhea
can be watery or exudative. The average duration of diarrhea in COVID 19
is 4 days and the frequency of defecation varies from 3 to 30 times per
day.[4, 5] The number of virus particles in the feces of patients
with diarrhea is higher than in patients without diarrhea, and the virus
is excreted in the feces for several weeks.
Intestinal involvement in COVID-19 has been reported in up to 50% of
studies. The duration of hospitalization, duration of elevated liver
enzymes, coagulopathy and high inflammatory markers in patients with
diarrhea are higher than patients without diarrhea, and if these
conditions are observed, the patient’s prognosis is worse.[4, 6, 7]