Just wondering if patients that cannot eat find an IV satisfying, or do they find themselves starving all day long?
In the hospital, they usually pass a tube through the nose down to the stomach (duodenum, actually), and feed them liquid food. (That’s not an IV, which means “intravenous”.)
I’m not sure how well that minimizes hunger pangs.
I thought IVs were for meds and stuff like saline. Feeding tubes are called nasogastric tubes.
ETA: late again due to finding a cite.
Normally, IVs only provide fluids and electrolytes (and ‘sugar’). If someone cannot eat long-term, and they cannot be fed into the stomach via a tube (through the nose or in a surgical hole through the belly) for any number of reasons, they can receive parenteral nutrition. This is still IV, but also contains virtually everything the body needs (such as vitamins, fats, proteins, electrolytes, trace elements, even medications sometimes).
As for feelings of hunger, typically these patients are too sick to care or otherwise have zero appetite.
Now, if someone cannot eat or drink after midnight for a surgical procedure tomorrow, but they have an IV running, that’s a different matter. Yeah, they’re starving. 
mmm
I was hospitalized at age 16 for a perintonsular abcess. I couldn’t eat for week, and the doctor started me back with jello and soup. I was starving. begged him to let me have solid food. He told me I probably wouldn’t be able to swallow it, but put in the order.
I have never looked forward to a meal so much in my life, before or since. When the dinner tray came I was practically drooling. It didn’t hurt any that the hospital was actually known for having good food.
The tray arrived…and the order hadn’t been changed. Soup and jello. I put the cover back on it, pushed it away and started crying. When the orderly came to pick up the tray and saw I hadn’t touched it, he asked me what was wrong. I still couldn’t talk, so I used my little notepad to tell him my sad story. He went back to the kitchen and got me a tray of real food.
It was some sort of fish almondine. I was able to get down about two bites.
Best food I’ve ever tasted. An IV line can save you from malnutrition but you’re still hungry.
One of my second cousins was born severely developmentally disabled and had to be fed with a stomach tube. He would get fussy when he was hungry and the fussiness would subside after he was fed.
You can be “fed” several ways if you can’t eat food, depending on what you need, how long you need it and what parts of your system are precluding you from eating food.
Say you have no teeth. You can still eat mashed, ground, pureed and soft foods. Your stomach and intestines still work, so you swallow the food and digest as normal from there.
OK, what if you can’t swallow? Then we can give you nutrients directly into your stomach, either with a naogastric tube (“ng tube”), which goes into the nose, down the throat and into the stomach, or with a gastric tube (“g-tube”) which is surgically implanted through a hole in your abdomen. We can put nutrients through the tube, basically like a shake, although it doesn’t need to taste good. We can also crush up some medicines and put them through the tube and get them to your stomach that way. From there, digestion proceeds as normal.
What if you are too weak to eat, or your doctor doesn’t want you to eat because you’re going to have surgery, or you’ve been very ill with vomiting and diarrhea and you can’t keep food down or you don’t have a stomach? Basically, we’re looking to bypass the stomach and intestines here. That’s when we’ll look into IV solutions. If you just have a bad tummy bug and you’re dehydrated from a few days of throwing up, we’re not too concerned about nutrients - you probably have enough reserves in your body to see you through a while without food. We are very concerned about water, though. So your standard rehydrating solution is going to be Saline, or a similar solution which has added electrolytes (called Lactated Ringers). It’s going to go through a small tube right into your bloodstream, no digestion required. We can also put some medicines through that same small tube, but only one thing can go through the tube at a time - that’s why if you need IV saline and IV medicine, they’re going to put two IV’s in, or they’re going to hang a “piggyback” with the medicine, which stops the saline while the medicine is running.
If your digestive system is out of order for longer than a week or so, then they’ll order something called Parenteral Nutrition - which literally means nutrition outside of the digestive tract. This is also IV, but it’s more than just water and electrolytes. This is a specially formulated bag of nutrients, often with another bag (a “piggyback”) of lipids, or fats. A patient can have partial parenteral nutrition, if they can eat some food but not enough to sustain them, or they can have total parenteral nutrition, if they can’t eat at all. Total parenteral nutrition, or TPN, is usually done through a more or less permanent tube that’s inserted into one of the larger blood vessels, not the tiny ones in your hand or forearm. There’s generally a “port” in the upper arm or near the shoulder where the tube can be accessed, and that line is used *only *for TPN, not for giving medications or drawing blood.
Now…to answer the OP: it depends. Generally, people who are very sick don’t have an appetite. One of the things we like to see, in fact, is a hungry patient, because it’s a sign they’re feeling better! But, of course, there are exceptions, and some people really do miss eating. Sometimes a patient who is NPO (not taking food by mouth) can chew on ice chips to satisfy the urge to chew and swallow something. But it’s not hunger like you feel at 5:30 before dinner’s ready, because there’s not the blood sugar triggers and the person’s cells aren’t really crying out for nutrients - but yes, there can be a “hunger” of habit and wanting to put something in your mouth, chew and swallow it.
That just raises the question: Can mogwai be fed on an IV after midnight?