Hi, my 78 yr old mother has had diarrhea all day, nauseated she did actually throw up 2x this morning.. Now she tells her stool is black and may have a small grade fever.. She has a supra pubic cath which was just replaced 3 weeks ago due to having hernia repair. in your opinion, could this be just a virus or should I take her to ER for possible infection (staph)..Need advice thank you