My father-in-law is COVID-19 positive, and he vomits whatever he eats. Is this a gastro problem?

Hi doctor,

My father-in-law is affected by the Coronavirus. He tested COVID-19 positive and then tested negative a week later. For the past 20 days, he is not able to eat anything. Every time he vomits what he eats even after medication provided by the government hospital along with Emiset. He got a stroke and had infections in the lungs during the active infection. As per the CT (computed tomography) scan, he had some minor blocks in the brain. Now 15 liters of oxygen was provided to him. He has hiccups continuously. Under critical care treatment, his pulse drops slightly today. He used to go unconscious repeatedly and fell in the ward. He had ulcer complaints and kidney problems during the high salt levels, and he is under medication for five years. As per hospital, now they only can concentrate on his current health conditions. He does not even identify us sometimes. He did not sleep well for nearly eight days, even with sleeping pills and injection, and he has a headache. His sugar and blood pressure are normal. Is this a gastro problem or something serious?