The number of gastrointestinal bleeding (GIB) cases in the Afzalipour Hospital is high. At the same time, this is the reference center for endoscopic treatment of GIB patients and the treatment center for patients with COVID-19 in Kerman province. Therefore, there is an increasing need to find the cause of GIB in COVID-19 patients, and the preferred method of investigation and timely treatment should be determined to improve the prognosis and prevent mortality. This study aimed to investigate the causes of GIB and its relationship with prognosis in patients with COVID-19 hospitalized in Afzalipour Hospital, Kerman.

In this case-control study, 127 patients with positive COVID-19 were examined. 64 cases had GIB and 63 cases were without GIB. In endoscopy department, the records of patients with COVID-19 who underwent upper endoscopy in the second half of 2020 were reviewed, and those who presented with hematomas and melena were included in the study. The patients' information and then their prognosis were recorded in the checklist. To analyze the data, descriptive statistics (prevalence, mean and standard deviation) and analytical (chi-square test, Pearson correlation coefficient) was used. If the data distribution is not normal, their equivalent non-parametric tests (Fisher's test and Spearman correlation coefficient) was used. Linear and logistic regression were used to determine the predictor variables of the desired main outcome.

The mean age of cases with GIB was higher (P=0.06). There was no significant difference between two groups in terms of gender. The duration of hospitalization of patients with GIB in the ICU was higher (p=0.03). After respiratory symptoms (47.2%); Coffee ground secretions and melena (25.2%) were the most frequent compared to other digestive symptoms (P=0.001). The frequency of intubation was higher in patients with GIB (P=0.124). Arterial blood oxygen saturation was lower in patients with GIB (P=0.143). The frequency of shortness of breath was higher in patients without GIB (P=0.001). In endoscopy findings, the highest frequency was related to normal findings (21%), then other findings were erosive gastritis (17.7%), gastric ulcer (9.7%), respectively. Most patients (67.2% in patients with GIB and 78% in patients without GIB) were discharged from the hospital, while 26.6% of patients with GIB and 18.9% of patients without GIB were died (P=0.007). Intravenous anticoagulant were risk factor of GIB in case group. But there was no significant relationship between the consumption of NSAID, oral anticoagulants and antiplatelet between the two groups. Previous history of GIB and chronic liver disease was a risk factor for GIB in patients with COVID-19. But there was no significant relationship with other diseases.

This study showed that GIB in COVID-19 patients mainly occurred in the elderly patients and was mostly due to erosive gastritis and gastric ulcer. The most common manifestations were melena and hemoglobin drop. Although the length of stay in the ICU was significantly higher in patients with GIB, most of the patients were discharged from the hospital, and GIB was not related to the threat of respiratory status of the patients.