To the Editor: A 67-year-old man with a history of chronic obstructive pulmonary disease, coronary artery disease, and diabetes mellitus presented with a five-day history of diarrhea. He reported three to four watery, nonbloody bowel movements per day. He did not report fevers, chills, cough, or shortness of breath. On presentation, he was afebrile and hemodynamically stable. He was breathing comfortably with oxygen saturation at 92% on his usual 3 L of oxygen at home. His lungs were clear to auscultation. Laboratory testing was notable for thrombocytopenia with a platelet count of 102 × 10³ per μL (102 × 10⁹ per L) and an elevated aspartate transaminase level of 96 U per L (1.60 μkat per L). He was negative for Clostridium difficile infection. Twelve hours into his hospitalization, he had a fever of 102°F (38.9°C) and a new cough. His oxygen requirement increased to 6 L to maintain an oxygen saturation greater than 88%. Chest radiography demonstrated bilateral interstitial opacities. Testing for coronavirus disease 2019 (COVID-19) was performed, and treatment with broad-spectrum antibiotics, and albuterol and ipratropium (Atrovent) through a metered-dose inhaler were initiated. He became increasingly hypoxic, requiring intubation and transfer to the intensive care unit. His COVID-19 test result subsequently returned positive.

Most patients with COVID-19 present with respiratory symptoms and signs. The Centers for Disease Control and Prevention currently recommends testing patients who have fever, cough, or shortness of breath, prioritizing those who are hospitalized or who are at highest risk of complications.¹ A case series of 138 hospitalized patients found that the most common symptoms of COVID-19 are fever (98.6%), fatigue (69.6%), dry cough (59.4%), myalgias (34.8%), and dyspnea (31.2%). Gastrointestinal symptoms such as diarrhea (10.1%), nausea (10.1%), vomiting (3.6%), and abdominal pain (2.2%) were less common.² However, another report suggests that many patients with COVID-19 may experience gastrointestinal symptoms, with 50.3% (n = 103) reporting a digestive symptom (anorexia, diarrhea, vomiting, or abdominal pain) at the time of admission.³ A case series of 1,141 patients hospitalized with COVID-19 found that 183 patients (16%) presented with only gastrointestinal symptoms.⁴

The clinical spectrum of COVID-19 is wide and not completely understood. Unexplained digestive symptoms, such as diarrhea, should raise the level of suspicion for COVID-19, even in the absence of respiratory features.