Suggest Treatment For Severe Headache, Vomiting And Fever

Hi. I was discharged from hospital today after a four day stay for severe headache/vomiting/high temp. CT/Lumbar puncture showed no trace of infection or bleeding. I was not given any antibiotics, just pain relief and anti nausea meds. Just before discharge I had a very bad smelling watery diarrhoea and this has continued for 5 hours since I have been home. Do I need to get tested or just take immodium?