My son is much older so his experience would be a bit different, however, he did do the EN for six weeks. He used the NG tube overnight (and he has continued with it as maintenance/supplement at 1/2 dose). He inserts the tube nightly and removes in the morning.
I do have a friend whose daughter is approx. 10 years old, she did exclusive EN over the summer and left the tube in - she had no problem. At his age, there would probably have to be a bit more care when 'playing' as it wouldn't be too difficult to pull out the tube while playing 'rough'. (No harm/pain would come from pulling it out suddenly, however, that would then require a reinsertion.)
GIs seem to differ re additional fluids with exclusive EN but, our GI allowed my son to have broth, clear juices (apple, etc with NO fibre or pulp), popsicles, freezies, etc. If your son's GI allows this... I arranged with my sons school to keep some freezies in their freezer and I sent him broth to have at lunch with his friends. The broth was a big help as he would have broth again for 'dinner'...
Although my son had his entire dosage overnight, as MLP said, this is probably not possible for younger children. As well, by having the dosage only overnight, my son did struggle a bit with hunger by the time evening came. I would imagine the hunger is alleviated by daytime NG feeds or by drinking shakes.
:ghug: