Hi Lizknits,
Sorry that your son is struggling with EEN. It's hard, and your son has done well to make it this far!
My daughter just could not drink the formula; we tried a lot of different brands and flavors, but all of them made her gag and feel sick. She was scared by the idea of the NG tube, but for her, it ended up being a good thing. Once it was in, she didn't have to taste the formula, and it made our relationship with her so much better because we weren't always begging her to try to drink it. The tube was very uncomfortable for her for 2 days, and then she hardly noticed it. During her EEN period, she chose to leave the tube in all the time, but now that she's doing supplemental EN at night, she's putting the tube in herself at night and removing it in the morning. Many kids are able to do that; there's a great video on youtube where a girl explains how to put in the tube.
Compliance was also easier for her because her doctor allowed her to get 10% of her calories from food. I know not all doctors allow that (and there's debate over whether that compromises the effectiveness of EEN), but most do allow a few foods, such as clear broth, clear popsicles, or hard candy. You might check with your doctor to see if you could add a few things.
We also tried not to eat in front of my daughter while she was doing EEN, and we avoided events with food.
Finally, E really did not want to do supplemental EN once the EEN period was done. I think because she was feeling so much better, she just didn't understand why it was still important. We didn't give her a choice about it--we treat it like a medicine. However, we did incentivize it--we give her $25 a week for doing it. That's a *lot* of money for her, and it completely changed her attitude about it.
Good luck--hope it gets easier for your son. I noticed from your other post that your son isn't on any other medicines yet. Are there any plans for a maintenance medicine? Usually EEN is just used to induce remission until another medicine can take over.