The answer varies from state to state. In NY, medical assistants can't administer medications, assess patients, or give injections. They can take vitals and provide other types of services.
It gives you a healthy digestive system, and it cleans it out. It can also help with weight control, since high-fiber foods make you feel full quicker.
If you were to only drink salt water the pressure in your blood would be very high, and a possible over-dose of the minerals in salt water leading to blury vision, migranes and kidney failure.