Prior to symptoms, an Ebola patient is not infectious. Once symptoms appear, they become progressively more infectious as time goes by.
Although many bodily fluids are mentioned as possibly being contaminated with virus, this paper shows that there actually is not virus in most bodily fluids. Few of the fluids had detectable viral RNA, and fewer still had culturable virus. The presence of RNA alone means nothing, if virus cannot be cultured from the same sample.
Now, that paper was limited and the methodology was not ideal, so I would be hesitant to say that the fluids found to be free of culturable virus would always be non-infective in every patient. Clearly, a more robust study needs to be done.
What I will say is that any bodily fluid contaminated with blood (even in quantities too small to see) is likely to be contagious.
In any case, a patient who has advanced far enough in the disease to be contagious through direct contact is ill enough to be in ICU in an ID unit. He or she is not traveling around potentially leaving a trail of infected vomit or feces.
Norovirus and the common cold are both highly contagious, far more than Ebola. You don't have to be in the same room as someone to catch either of those two diseases from them.
Even in an ICU the patient can trail infectious fluids all over the room they occupy. Not only physicians, but nursing staff, CNAs and janitors, lab personnel, kitchen workers delivering meals are all exposed to these fluids. Unlike most pontificating here, I will be on the front line caring for anyone in my institution that may have Ebola. If I come in contact with any suspected or diagnosed Ebola patients, my little one is on her way to relatives for the duration of the time I care for them and 21 days after. I am well aware of isolation techniques and a veteran of 30 years medical practice, including when HIV was an unknown quantity. This is one I am concerned enough about to isolate myself from family if I encounter an infected individual.
And sorry, to get infected with the common cold, influenza or norovirus, you still have to come in contact with infectious body fluids. The isolation on all of those is contact and droplet the same as ebola. It is orders of magnitude easier to contact ebola than other blood borne illnesses such as HIV and hepatitis C, both of which I deal with on a daily basis.