key: cord-323751-ofz4htdb
authors: Liu, Yuzhi; Xiang, Lingya; Deng, Kai
title: Focusing on gastrointestinal symptoms in COVID-19 is far from enough
date: 2020-05-18
journal: Gastroenterology
DOI: 10.1053/j.gastro.2020.05.043
sha: 
doc_id: 323751
cord_uid: ofz4htdb

nan

We had great interest in the article by Yael R et al [1] . It confirmed that the gastrointestinal symptoms (especially for diarrhea) were common in COVID-19 patients . In comparison with the other reports on this topic [2, 3] , this case-control study can provide more significance and credibility owing to the correction of baseline status for gastrointestinal symptoms in non-COVID-19 patients. However, we do have some concerns about it.

Firstly, the setting of the control group was arbitrary. The distribution and detail of various diseases were unclear (lung diseases or others). It may reduce the reliability benefited from case-control study.

Secondly, the evaluation of gastrointestinal symptoms mainly depended on the subjective judgement of patients, which might be inaccurate and misunderstood. It was imperfect that no objective evidence from laboratory or imaging examination confirmed the final conclusion.

Thirdly, huge heterogeneity existed among the non-severe, severe and critical groups classified by the COVID-19 Guidance [4] . The subgroup analysis was performed on the basis of the ward where the COVID-19 patients stayed (hospital or ICU admission). It was lack of accuracy and rigor for differentiating the condition status in COVID-19 patients. It may neutralize the differences relating to various degrees of COVID-19.

In response to the shortcomings above, our clinical data can provide more additional evidences to refine this topic on COVID-19. For balancing the baseline status in control groups, 122 non-COVID-19 pneumonia, 99 lung tumors and 248 healthy subjects participating medical examination, who were definitely excluded from COVID-19, were randomly recruited for comparative analysis at the corresponding period. In Renmin Hospital of Wuhan University (January to March, 2020), 148 COVID-19 patients with their information about gastrointestinal symptoms and fecal examination were recruited.

The informed consent was waived for this minimal risk study approved by the ethics committee. For adding the objective evidence, the gastrointestinal symptoms and fecal examination results were simultaneously collected and analyzed. It was observed that the incidence of diarrhea in COVOD-19 pneumonia group was significantly higher than that of non-COVID-19 pneumonia and lung tumor groups (both P < .01). In comparative analysis of fecal examination results, the change of fecal property with accordance to diarrhea was confirmed in the COVID-19 group (all P < .001). The erythrocyte, leukocyte and occult blood (OB) in feces can be used as indirect predictors for gastrointestinal damage. After excluding the critical cases from COVID-19 group, the detection rates of erythrocyte, leukocyte and OB in feces were not higher than those of the control groups (non-COVID-19 pneumonia, lung tumor and healthy subject).

For rigorous analysis, the patients in COVID-19 group were divided into three subgroups (76 no-severe, 55 severe and 17 critical cases). No significant difference was found (all P > .05) in the subgroup analysis (severe vs. non-severe, critical vs. non-critical, and survivor vs. non-survivor) of gastrointestinal symptoms, except for anorexia between survivors and non-survivors (P = .009). In the subgroup analysis of fecal examination results, the detection rates of leukocytes and OB in feces were only significant different between critical and non-critical group (both P < .001). In the survival analysis, the abnormal results of leukocyte and OB in feces were obviously associated with higher mortality risk (Log-rank test, P < .001). The detail data were shown in supplementary Table 1 .

Actually, over 80% COVID-19 patients are non-critical cases [5] . The risk for abnormal fecal examination (erythrocyte, leukocyte and/or OB) results in non-critical COVID-19 may be similar to baseline status of others lung diseases, but the risk in critical COVID-19 increased obviously. The appearance of erythrocyte, leukocyte and OB in feces represented the gastrointestinal damage, and indicated the increased risk of death in case of the exclusion of underlying diseases in gastrointestinal tract. It is known that gastrointestinal ulcer and bleeding is common in critical patients, especially in those with respiratory failure [6, 7] . High possibility of multiple organ dysfunction syndrome (MODS) in critical COVID-19 cases can increase the risk of secondary damage in gastrointestinal tract, resulting in the occurrence of abnormal fecal examination. Meanwhile, the occurrence of gastrointestinal damage can prompt gastrointestinal dysfunction which accelerate the process from MODS to death.

Consequently, the abnormal fecal examination results may be used as risk factors of mortality in COVID-19 patients, especially for critical cases.

Among the gastrointestinal symptoms relative to COVID-19, the diarrhea is confirmed as the most common one. But it is not comprehensive to simply focus on these gastrointestinal symptoms. For gastrointestinal evaluation, the fecal examination is a simple and economic test which may provide more valuable information about gastrointestinal damage and prognostic risk.

World Health Organization: Clinical management of severe acute respiratory infection when Novel coronavirus (nCoV) infection is suspected: Interim Guidance