The new coronavirus disease (COVID–19) causes gastrointestinal symptoms as well as respiratory symptoms. We report a case of massive refractory diarrhea from the perspective of gut microbiota. A 60–year–old man was transferred with dyspnea. He was diagnosed as having COVID–19 and was intubated on mechanical ventilation with extracorporeal membrane oxygenation. He was administered anti–viral drug therapy and antibiotics. He suffered from diarrhea from day 12 and produced a maximum of about 6,384mL/day of watery diarrhea on day 21. He required massive transfusion and catecholamines for circulatory support. Adsorbents, pectin–containing oligomeric formulas and synbiotics were administered, which decreased the amounts of diarrhea. After day 30, the amount of diarrhea decreased to less than 1,000mL/day. Fecal metagenomic analysis showed the proportions of Enterococcus and Staphylococcus in the phylum Firmicutes were the most dominate at the genus level. The proportion of Bacteroidetes was less than 1%, and the gut microbiota had dramatically changed. Thereafter, his diarrhea decreased to occasional instances, and he was transferred to another ward on day 104. Therapy for intestinal complications might be important in treating COVID–19. Intestinal therapy such as adsorbents might be effective in patients with massive diarrhea.
新型コロナウイルス感染症（COVID–19）に伴う難治性大量下痢症の1例(A case of refractory massive diarrhea in a patient with COVID–19)