Reflux/colic= milk help!!

[ck202020]

hiya hope someone can help me !...
My son who's now 11 weeks (was born 3 weeks early, weighed 5lb 4) started suffering from colic ( or what I thought was colic?) From about 4 weeks...
Finally changed his milk to a comfort one (hipp) as the health visitor told me too, felt like it worked for a few weeks but now he seems like hes suffering from reflux help ?!
He seems happy, feeding well (now 11lb), smiling, sleeping ok BUT hes now bringing up clear liquid, coughing and sometimes has bad breath and grunting in his sleep...
Should I now go back to normal hipp milk as now hes older ?
Give him a little water inbetween feeds ?
Orrrr... ?

Thanks x

We found the Cow and Gate Comfort milk to help with the colic and were prescribed baby gaviscon by the Gp which seemed to help but it did cause constipation which then gave us another problem to sort out unfortunately. Thankfully my baby grew out of the colic and reflux at around 16 weeks and we stopped using the gaviscon.