COVID-19(8) SARS-CoV-2(6) Intravenous immunoglobulin(4) Gastrointestinal(4) post-viral.(4) intractable(4) reflected(4) Symptom(4) autoimmune dysautonomia(4) over(4) elevated(4) ganglionic(4) antibody(4) Sweat(4) nausea(4) the patient(4) autonomic(4) viral infection(4) IVIG(4) autoimmune gastrointestinal dysmotility (AGID)(4) bowel(4) treated(4) treatable(4) Treatment(4) SARS-COV-2 infection(4) Autoimmune(4) impairment(4) required(4) baseline(4) PCR(3)