Which should I try Neocate or Elecare?

Enfamil Gentease in the hospital (did fine with it)

Day 3: Carnation Good Start and breastmilk – Had very very bad gas, crying and became very constipated.

Then tried Regular Enfamil and and breastmilk and got diaherra and extreme gas

Then went to Lactose Free and got so constipated he had to be cleaned out by our doctor and had blood in his poop (doctor says from a tear).

Then went to Alimentum formula and still was very very gassy and always crying in pain, grunting, straining.

Then tried Gentlease and his bowel movements were normal and soft, but smelled like rotten eggs and he still had tons and tons of gas and still constant crying, grunting, straining.

Finally went to Nutramigen and started Axid for silent reflux.

So that is where we are now. He is having normal bowel movements, but grunts and strains and his stomach gets hard as a rock. Does not sleep longer than 1 1/2 hours at a time to be wakened by gas or grunting and straining. It is like he is constipated or trying to have a bowel movement 24 hours a day, but his poops are normal.

So now we are going to try Neocate or Elecare. We have a GI appt. Monday morning, but I can’t keep him on the Nutramigen over the weekend. He is in to much pain. I got free samples of both from the Childrens Hospital, but now am confused on which one to start with.

Is there a difference? Did you have success on one v/s the other. Does anyone know what a GI specialist normally starts infants off on.

Thanks so much!!Wendy