Can a restaurant refuse service to a customer - health hazard? (IA)

Trigger Warning - bodily fluids.

I am posting this for a friend who is dealing with this situation. She works at a restaurant, and a new customer has went to this restaurant a few times in the past couple months. Not sure exactly what medical condition this customer has, but she has open sores all over her legs that leak pus. The customer wears shorts so the pus leaks all over the booth, floor, etc. She’s also gone to the restaurants public bathroom and left a trail of bodily fluids from her table to the bathroom, and on the bathroom floor. The customer does not even attempt to clean up after herself, so staff end up having to wipe and disinfect the area after she leaves. Servers have complained, but management is telling staff that they can’t refuse service to her because of this. Other customers have also complained/left the restaurant that were sitting near this person.

I know management is trying to avoid being sued, but legally can the restaurant refuse service to this customer? My friend has health related anxiety so this is obviously triggering it. I will pass on any information commented to my friend. Thank you.