Elecare for CMPI and reflux

My LO has a CMPI and was on Nutrimagen. He did great for about a week and a half and then seemed to regressed. He started having mucus in his stool again and I noticed reflux symptoms. He was sleeping horribly (which was a drastic change, he was sleeping 4-5 hours a night prior) up every hour.

I took him to a GI doctor because his ped chalked it up to "colic". The GI doc advised to switch to Elecare.. started him on it today. Just curious if anyone else has their LO's on Elecare or went through something similar?