Question about Neocate and cramping?

Cody is almost 5 months old. We are on night 2 with Neocate. Cody has been on Nutramegin for 4 months and was doing just okay. He is on the proper dose of Prevacid according to marci’s kids site but is fussy pretty much 80 % of our day. Tonight he screamed for about 2 hours on and off.It seemd like he was having really bad stomach cramps. They came in waves We have’t had a night like that in a long time. I am not sure if I should discontinue the neocate or just keep pumping it in him. I add oatmeal to his bottles, but I was doing that before. Should I stop doing that? I know they say it takes a good week to 2 weeks when trying a new formula, but I don’t want to put Cody through many more nights like this. What do think??? Thanks for any help you can give!