This is so weird that I can't remember if I had an NG tube after my colon resection or liver resection. I would think I would have had one after the liver resection, as it was a very long open (way open) abdominal surgery. It helps that I'm always completely amnesic for three days after general anesthesia .
Anyway, just speaking as a nurse, if anyone has to get and NG while they are awake, it may help if you ask your nurse to put the first 6 or so inches of the tube in a cup of ice before inserting it, and second, remember, even though you won't feel like it, to swallow, swallow, swallow while it is being put in. Ask them if you could have a few tiny sips of water while they are putting it in. This makes it significantly easier to get the tube down, and will distract you in the process. Taking any of these tubes out should really be no big deal. The catheter has a balloon that it inflated after the tube is inserted (which is what keeps it in the bladder), once that balloon is deflated by your nurse, which is done by aspirating from a tube within the tube, the catheter will basically fall out on it's own. Easy-peasy. NG tube removal? Count backwards from 10 slowly--the tube will be out long before you get to ten. JP drain, same deal. You'll do fine!
Best of luck,
Bev