When it was time to feed her, caretakers would have attached a syringe to the end of her tube, and pulled out the plunger to see how much fluid came out of her stomach. If there wasn't too much in there already, they'd fill up the syringe with a commercial liquid diet product like Ensure. (A single meal consists of 2 or 3 cans, or you can use regular food that's been liquefied in a blender.) It's also possible that Schiavo received continuous feeding using a 24-hour pumping mechanism, which is used for patients at higher risk for regurgitation and aspiration pneumonia.
http://slate.msn.com/id/2115227/ <-- Link
Doesn't sound like too much of a hassle. My wife is undertaking a special procedure at this very minute, heating some soup and spreading egg salad on some bread.
I haven't found information regarding "tube in" tube out" chronology, most of the search engine hits are current events.
It is used for people who have a problem with their digestive system, and can't take food through the stomach or intestines. It is pumped into your bloodstream through a wide bore (pic)more permanent line intravenously. I was on one myself when my pancreas failed. It's extraordinarily expensive, and if a feeding tube can be used, it is.
How you feed a person at home is quite different than how an institution does. They have to follow protocol to prevent lawsuits. As I said, it is NOT something care homes do for convienience. They are prone to infections as well.