Feeding tubes come in many forms. There are NG tubes (down the nose and into the stomach), OG tubes (down the mouth and into the stomach), G tubes (into the belly), and G/J tubes (one line into the belly and one straight into the intestines), among others. We have experience with NG tubes (LB and LK in the NICU), OG tube (LK in the NICU), and G tubes (LE). LB also had TPN, which is IV nutrition, while she was in the NICU.
People have feeding tubes for a variety of reasons. Some people do not have the skills to eat. My preemies in the NICU had to master the suck, swallow, breathe pattern. Before they got it down, they were fed through tubes to prevent them from burning too many calories learning how to eat. They also could exhaust themselves trying to eat and their tiny bodies could not keep up. Some people have them because their insides do not work properly. For some people, this means that their stomach cannot handle anything in it, and for others it means their intestines do not work right. Either way, the tube allows them to eat and receive the nutrition they need.
Some people, like LE, could eat and eat and eat by mouth but could not gain weight. She got her tube for her Failure to Thrive and volume sensitivity. She uses the tube now for fluids, finishing her feeds, and medicine. She quite literally would not be alive today without the tube. It is a lifeline, and I am grateful for it.