Does he have a Kangaroo pump? If he has a PEG tube, there is a machine called a Kangaroo pump that either insurace will pay for monthly or you can rent (ours is $600.00 a month)that you can connect to his feeding tube (and use a lot of tape so it doesnt come out)and it will dispence a few drops every few seconds into his stomach.
My fiancee, Charlie, couldnt keep a thing down due to his mucus, but the pump alows him to digest the Ensure or Boost before he gets sick. He has lost 15 lbs. It is, however a long process- 4 cans can take anywhere from 10-12 hours to pump- so doing this while he sleeps will ease this anxietyf or him. I know how much Charlie just wants to throw the pump away, but as thier support, we just have to keep on pushing and encourging!