So had my son on similac advance he did fine first two weeks spit up occasionally n then turned for worst vomiting everywhere so I switched him to enfamil AR cause I read it's really good for spitting up well then he became extremely fussy was having trouble with BM so nurse recommended prune juice mix with water throughout day which is making him go atleast once or twice a day and bowel movements looks normal but he is now still horribly fussy took him to doc she said he probably has acid reflux and prescribed him 3/4 ml of Zantac twice a day I started it tonight and he is worse then ever he was up from 6:30-1am n now again woke up at 3 am and is so uncomfortable and has literally drank almost 12 oz in that short period of time where it's normally 6oz like he is uncomfortable yet starving but then he is spitting up cause he is over eating any suggestions I'm almost thinking he might have an allergies to formula in tired of waiting on doc I need sleep and I know he is overtired he is 5 weeks normally he would go to sleep 6pm-10:30 feed him n then wake up At 2:30 n back up at 5:30 but i gave him the meds at 10:00 n he was up the whole time from 6pm-1am n then back up at 3am so he has literally slept 2 hours from 6pm-3am help if you have any suggestions formula change or similar experience he maybe slept 9 hours total in a 24 hour period of time that ain't right for a 5 weeks old I'm open to try new formula soy anything please help!