Sorry to hear about your son. I'm not sure what you mean by a jej feed, I am eating normally.
Actually this blockage, whatever the cause, was the first incident since my operation last December - perforation through an old surgery to my duodenum. I don't know all the fancy terms the doctors used to describe this. I've been feeling great since this last blockage, the operation and ileostomy made a huge difference. I can eat raw fruit again!
One thing I am doing differently is drinking more water in between meals, then not eating and drinking together at the same time. I am hungry almost all the time so it's not hard to get my saliva going - I think this is very important to assist digestion and providing enzymes to the stomach and intestine. Also, taking small bites, chewing lots so it's almost liquid before I swallow, and taking it very s-l-o-w during the meal.
I am eating no more leftovers to reduce bad bacteria. I am trying to eat lots of protein (chicken today) and rice, with a light sauce (mild butter chicken sauce, milk, yoghurt).
Does he feel pain before he vomits? Can he fast for a day or so, or can you blend food so it is soft and smooth? Might help reduce inflammation.