My granddaughter is having the same problems....She is almost 5 mo's old now and has not left the hospital since her birth. She had MI at birth and had surgery, she didn't have the reconnection until alittle over a month ago, she has only gained 2 pounds since her birth and the just did a G tube on the 17th of this month. She is on progestamil thur the G tube and also on TPN. TPN can cause liver damage and for a while Graycie was yellow on and off for months. They said she cannot gain weight rite now without the TPN and i have researched this. I asked her GI dr about a new TPN that is not FDA approved at this time but is having great results, it is made with Omega 3 instead of the Omega 6 that they usually use and it does not affect the liver and in some cases will reverse the liver damage already done. They said they do have it at the hospital and can use it for compassionate use. You might want to ask her GI dr about this. Also ask about viokase, which is an enzeme that allows her to digest the nutrients easier and is used on preterm babies. Sorry this is so long but i can really relate to you and am going thru the same thing with my granddaughter. Ask questions until you understand what and why they are doing what they are doing. It will put your mind at rest and make you feel more empowered. I dont remember the name of the TPN rite now but i will look it up for you if you want. God Bless