WRONG! You can not discriminate against someone due to illness. Now if they don't call in/have doctors note, then they can be terminated.
When the person finally contacts the employer, they will need documentation from a doctor noting they were ill for however long (and no, they do not need to explain what - HIPAA confidentiality).
Where do you get your info, you need much more than a doctor's note...also you can discriminate on illness it's not a protected class (race, color, religion, sex, national origin, disability, genetic information, or age)...pregnancy can be a reason not to hire someone. You can also still be removed from duty if the pregnancy prevents one from doing the job properly, so there are loopholes in that.
First...outside of pregnancy all bets are off and even then I am sure they can re-assign you to another position. This is the one holy grail that's been established and most company's don't want to go there. Companies also are not required to give 'sick time' with pay.
FMLA is not automatic. You have to be working a year plus 1250 hours (for most this would be almost 2 years of employment) prior to the leave request/situation. Your employer needs to employ at least 50 employees. You also have to be hospitalized or a situation where multiple leaves are needed due to a treatment plan. Just calling in sick and going to a doctor multiple times can still warrant a termination. Going to a doctor and finding out you have cancer and need to go in for treatment 3 times a week over a period of time is much different.
What you get is about 3 months of time and it can be without pay. If you go beyond that, you can be terminated.
This is the basics....California is the best for maternity leave I think you can be out almost a full year and still make half your pay.
My company offers long and short time leave. It's tiered on time in service, but after about 7 years you can make 100% pay for the first 6 weeks and then it drops off over the next 6 weeks.