Gaviscon won't stop the reflux it will just ease the discomfort of the reflux. Like if we took gaviscon for heartburn. It could obviously be something else so I would advise letting your Dr know. Both my babies have had reflux and gaviscon done nothing for them (except cause constipation). They both needed omeprazole for a while to treat the reflux.
What other symptoms? X maybe observe for milk allergy & take back to gp x