Formula Allergy- again

Little man had a rough night last night.  He threw up multiple times and by this morning had developed a terrible rash all over his body.  He looked miserable- eyes bloodshot and sunken in.  He was very agitated.  He was having an allergic reaction to the new formula that we started yesterday.  We stopped that formula and returned to the previous formula, Elecare, and decided during rounds, to "regress" a bit- which is necessary- to get success by feeding him continuous for 18 hours a day at a slow rate and 6 hours off.  Hopefully, his body just needs time to heal and will be successful at this plan and eventually we can build from there.  He wrenched in pain and threw up two more times this afternoon; however, we suspect it was due to residual of yesterday's formula was still in his stomach.  Prayerfully, he will have a better night!  They did an echo today just to make sure cardiac is not the cause of his feeding issues.  Thanks to God, his heart function showed some improvement since the last echo from 7/31.  The size of his heart has also gotten smaller on X-rays, which is good news, as well.  It seems so crazy that with all of his heart issues, GI issues are what is keeping him in the hospital.  We pray that cardiac continues to stay strong and his reflux is controlled with our new formula and rate.